diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-xiic.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xiic.c | 1388 |
1 files changed, 1075 insertions, 313 deletions
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index 3d0f0520c1b4..28015d77599d 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -1,22 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * i2c-xiic.c * Copyright (c) 2002-2007 Xilinx Inc. * Copyright (c) 2009-2010 Intel Corporation * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - * - * * This code was implemented by Mocean Laboratories AB when porting linux * to the automotive development board Russellville. The copyright holder * as seen in the header is Intel corporation. @@ -30,19 +17,25 @@ */ #include <linux/kernel.h> #include <linux/module.h> -#include <linux/init.h> #include <linux/errno.h> +#include <linux/err.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/i2c.h> #include <linux/interrupt.h> -#include <linux/wait.h> -#include <linux/i2c-xiic.h> +#include <linux/completion.h> +#include <linux/platform_data/i2c-xiic.h> #include <linux/io.h> #include <linux/slab.h> -#include <linux/of_i2c.h> +#include <linux/of.h> +#include <linux/clk.h> +#include <linux/pm_runtime.h> +#include <linux/iopoll.h> +#include <linux/spinlock.h> #define DRIVER_NAME "xiic-i2c" +#define DYNAMIC_MODE_READ_BROKEN_BIT BIT(0) +#define SMBUS_BLOCK_READ_MIN_LEN 3 enum xilinx_i2c_state { STATE_DONE, @@ -50,50 +43,126 @@ enum xilinx_i2c_state { STATE_START }; +enum xiic_endian { + LITTLE, + BIG +}; + +enum i2c_scl_freq { + REG_VALUES_100KHZ = 0, + REG_VALUES_400KHZ = 1, + REG_VALUES_1MHZ = 2 +}; + /** * struct xiic_i2c - Internal representation of the XIIC I2C bus - * @base: Memory base of the HW registers - * @wait: Wait queue for callers - * @adap: Kernel adapter representation - * @tx_msg: Messages from above to be sent - * @lock: Mutual exclusion - * @tx_pos: Current pos in TX message - * @nmsgs: Number of messages in tx_msg - * @state: See STATE_ - * @rx_msg: Current RX message - * @rx_pos: Position within current RX message + * @dev: Pointer to device structure + * @base: Memory base of the HW registers + * @completion: Completion for callers + * @adap: Kernel adapter representation + * @tx_msg: Messages from above to be sent + * @lock: Mutual exclusion + * @tx_pos: Current pos in TX message + * @nmsgs: Number of messages in tx_msg + * @rx_msg: Current RX message + * @rx_pos: Position within current RX message + * @endianness: big/little-endian byte order + * @clk: Pointer to AXI4-lite input clock + * @state: See STATE_ + * @singlemaster: Indicates bus is single master + * @dynamic: Mode of controller + * @prev_msg_tx: Previous message is Tx + * @quirks: To hold platform specific bug info + * @smbus_block_read: Flag to handle block read + * @input_clk: Input clock to I2C controller + * @i2c_clk: I2C SCL frequency + * @atomic: Mode of transfer + * @atomic_lock: Lock for atomic transfer mode + * @atomic_xfer_state: See STATE_ */ struct xiic_i2c { - void __iomem *base; - wait_queue_head_t wait; - struct i2c_adapter adap; - struct i2c_msg *tx_msg; - spinlock_t lock; - unsigned int tx_pos; - unsigned int nmsgs; - enum xilinx_i2c_state state; - struct i2c_msg *rx_msg; - int rx_pos; + struct device *dev; + void __iomem *base; + struct completion completion; + struct i2c_adapter adap; + struct i2c_msg *tx_msg; + struct mutex lock; + unsigned int tx_pos; + unsigned int nmsgs; + struct i2c_msg *rx_msg; + int rx_pos; + enum xiic_endian endianness; + struct clk *clk; + enum xilinx_i2c_state state; + bool singlemaster; + bool dynamic; + bool prev_msg_tx; + u32 quirks; + bool smbus_block_read; + unsigned long input_clk; + unsigned int i2c_clk; + bool atomic; + spinlock_t atomic_lock; /* Lock for atomic transfer mode */ + enum xilinx_i2c_state atomic_xfer_state; +}; + +struct xiic_version_data { + u32 quirks; +}; + +/** + * struct timing_regs - AXI I2C timing registers that depend on I2C spec + * @tsusta: setup time for a repeated START condition + * @tsusto: setup time for a STOP condition + * @thdsta: hold time for a repeated START condition + * @tsudat: setup time for data + * @tbuf: bus free time between STOP and START + */ +struct timing_regs { + unsigned int tsusta; + unsigned int tsusto; + unsigned int thdsta; + unsigned int tsudat; + unsigned int tbuf; }; +/* Reg values in ns derived from I2C spec and AXI I2C PG for different frequencies */ +static const struct timing_regs timing_reg_values[] = { + { 5700, 5000, 4300, 550, 5000 }, /* Reg values for 100KHz */ + { 900, 900, 900, 400, 1600 }, /* Reg values for 400KHz */ + { 380, 380, 380, 170, 620 }, /* Reg values for 1MHz */ +}; #define XIIC_MSB_OFFSET 0 -#define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET) +#define XIIC_REG_OFFSET (0x100 + XIIC_MSB_OFFSET) /* * Register offsets in bytes from RegisterBase. Three is added to the * base offset to access LSB (IBM style) of the word */ -#define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */ -#define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */ -#define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */ -#define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */ -#define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */ -#define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */ -#define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */ -#define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */ -#define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */ -#define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */ +#define XIIC_CR_REG_OFFSET (0x00 + XIIC_REG_OFFSET) /* Control Register */ +#define XIIC_SR_REG_OFFSET (0x04 + XIIC_REG_OFFSET) /* Status Register */ +#define XIIC_DTR_REG_OFFSET (0x08 + XIIC_REG_OFFSET) /* Data Tx Register */ +#define XIIC_DRR_REG_OFFSET (0x0C + XIIC_REG_OFFSET) /* Data Rx Register */ +#define XIIC_ADR_REG_OFFSET (0x10 + XIIC_REG_OFFSET) /* Address Register */ +#define XIIC_TFO_REG_OFFSET (0x14 + XIIC_REG_OFFSET) /* Tx FIFO Occupancy */ +#define XIIC_RFO_REG_OFFSET (0x18 + XIIC_REG_OFFSET) /* Rx FIFO Occupancy */ +#define XIIC_TBA_REG_OFFSET (0x1C + XIIC_REG_OFFSET) /* 10 Bit Address reg */ +#define XIIC_RFD_REG_OFFSET (0x20 + XIIC_REG_OFFSET) /* Rx FIFO Depth reg */ +#define XIIC_GPO_REG_OFFSET (0x24 + XIIC_REG_OFFSET) /* Output Register */ + +/* + * Timing register offsets from RegisterBase. These are used only for + * setting i2c clock frequency for the line. + */ +#define XIIC_TSUSTA_REG_OFFSET (0x28 + XIIC_REG_OFFSET) /* TSUSTA Register */ +#define XIIC_TSUSTO_REG_OFFSET (0x2C + XIIC_REG_OFFSET) /* TSUSTO Register */ +#define XIIC_THDSTA_REG_OFFSET (0x30 + XIIC_REG_OFFSET) /* THDSTA Register */ +#define XIIC_TSUDAT_REG_OFFSET (0x34 + XIIC_REG_OFFSET) /* TSUDAT Register */ +#define XIIC_TBUF_REG_OFFSET (0x38 + XIIC_REG_OFFSET) /* TBUF Register */ +#define XIIC_THIGH_REG_OFFSET (0x3C + XIIC_REG_OFFSET) /* THIGH Register */ +#define XIIC_TLOW_REG_OFFSET (0x40 + XIIC_REG_OFFSET) /* TLOW Register */ +#define XIIC_THDDAT_REG_OFFSET (0x44 + XIIC_REG_OFFSET) /* THDDAT Register */ /* Control Register masks */ #define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */ @@ -136,18 +205,15 @@ struct xiic_i2c { #define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS) -/* The following constants are used with the following macros to specify the - * operation, a read or write operation. - */ -#define XIIC_READ_OPERATION 1 -#define XIIC_WRITE_OPERATION 0 - /* * Tx Fifo upper bit masks. */ #define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */ #define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */ +/* Dynamic mode constants */ +#define MAX_READ_LENGTH_DYNAMIC 255 /* Max length for dynamic read */ + /* * The following constants define the register offsets for the Interrupt * registers. There are some holes in the memory map for reserved addresses @@ -161,6 +227,14 @@ struct xiic_i2c { #define XIIC_RESET_MASK 0xAUL +#define XIIC_PM_TIMEOUT 1000 /* ms */ +/* timeout waiting for the controller to respond */ +#define XIIC_I2C_TIMEOUT (msecs_to_jiffies(1000)) +/* timeout waiting for the controller finish transfers */ +#define XIIC_XFER_TIMEOUT (msecs_to_jiffies(10000)) +/* timeout waiting for the controller finish transfers in micro seconds */ +#define XIIC_XFER_TIMEOUT_US 10000000 + /* * The following constant is used for the device global interrupt enable * register, to enable all interrupts for the device, this is the only bit @@ -171,49 +245,104 @@ struct xiic_i2c { #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos) #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos) -static void xiic_start_xfer(struct xiic_i2c *i2c); +static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num); static void __xiic_start_xfer(struct xiic_i2c *i2c); +static int xiic_i2c_runtime_suspend(struct device *dev) +{ + struct xiic_i2c *i2c = dev_get_drvdata(dev); + + clk_disable(i2c->clk); + + return 0; +} + +static int xiic_i2c_runtime_resume(struct device *dev) +{ + struct xiic_i2c *i2c = dev_get_drvdata(dev); + int ret; + + ret = clk_enable(i2c->clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + return ret; + } + + return 0; +} + +/* + * For the register read and write functions, a little-endian and big-endian + * version are necessary. Endianness is detected during the probe function. + * Only the least significant byte [doublet] of the register are ever + * accessed. This requires an offset of 3 [2] from the base address for + * big-endian systems. + */ + static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value) { - iowrite8(value, i2c->base + reg); + if (i2c->endianness == LITTLE) + iowrite8(value, i2c->base + reg); + else + iowrite8(value, i2c->base + reg + 3); } static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg) { - return ioread8(i2c->base + reg); + u8 ret; + + if (i2c->endianness == LITTLE) + ret = ioread8(i2c->base + reg); + else + ret = ioread8(i2c->base + reg + 3); + return ret; } static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value) { - iowrite16(value, i2c->base + reg); + if (i2c->endianness == LITTLE) + iowrite16(value, i2c->base + reg); + else + iowrite16be(value, i2c->base + reg + 2); } static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value) { - iowrite32(value, i2c->base + reg); + if (i2c->endianness == LITTLE) + iowrite32(value, i2c->base + reg); + else + iowrite32be(value, i2c->base + reg); } static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg) { - return ioread32(i2c->base + reg); + u32 ret; + + if (i2c->endianness == LITTLE) + ret = ioread32(i2c->base + reg); + else + ret = ioread32be(i2c->base + reg); + return ret; } static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask) { u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); + xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask); } static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask) { u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); + xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask); } static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask) { u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); + xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask); } @@ -223,19 +352,140 @@ static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask) xiic_irq_en(i2c, mask); } -static void xiic_clear_rx_fifo(struct xiic_i2c *i2c) +static int xiic_clear_rx_fifo(struct xiic_i2c *i2c) { u8 sr; + unsigned long timeout; + + timeout = jiffies + XIIC_I2C_TIMEOUT; for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET); !(sr & XIIC_SR_RX_FIFO_EMPTY_MASK); - sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) + sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) { xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); + if (time_after(jiffies, timeout)) { + dev_err(i2c->dev, "Failed to clear rx fifo\n"); + return -ETIMEDOUT; + } + } + + return 0; +} + +static int xiic_wait_tx_empty(struct xiic_i2c *i2c) +{ + u8 isr; + unsigned long timeout; + + timeout = jiffies + XIIC_I2C_TIMEOUT; + for (isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); + !(isr & XIIC_INTR_TX_EMPTY_MASK); + isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET)) { + if (time_after(jiffies, timeout)) { + dev_err(i2c->dev, "Timeout waiting at Tx empty\n"); + return -ETIMEDOUT; + } + } + + return 0; +} + +/** + * xiic_setclk - Sets the configured clock rate + * @i2c: Pointer to the xiic device structure + * + * The timing register values are calculated according to the input clock + * frequency and configured scl frequency. For details, please refer the + * AXI I2C PG and NXP I2C Spec. + * Supported frequencies are 100KHz, 400KHz and 1MHz. + * + * Return: 0 on success (Supported frequency selected or not configurable in SW) + * -EINVAL on failure (scl frequency not supported or THIGH is 0) + */ +static int xiic_setclk(struct xiic_i2c *i2c) +{ + unsigned int clk_in_mhz; + unsigned int index = 0; + u32 reg_val; + + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, + "%s entry, i2c->input_clk: %ld, i2c->i2c_clk: %d\n", + __func__, i2c->input_clk, i2c->i2c_clk); + + /* If not specified in DT, do not configure in SW. Rely only on Vivado design */ + if (!i2c->i2c_clk || !i2c->input_clk) + return 0; + + clk_in_mhz = DIV_ROUND_UP(i2c->input_clk, 1000000); + + switch (i2c->i2c_clk) { + case I2C_MAX_FAST_MODE_PLUS_FREQ: + index = REG_VALUES_1MHZ; + break; + case I2C_MAX_FAST_MODE_FREQ: + index = REG_VALUES_400KHZ; + break; + case I2C_MAX_STANDARD_MODE_FREQ: + index = REG_VALUES_100KHZ; + break; + default: + dev_warn(i2c->adap.dev.parent, "Unsupported scl frequency\n"); + return -EINVAL; + } + + /* + * Value to be stored in a register is the number of clock cycles required + * for the time duration. So the time is divided by the input clock time + * period to get the number of clock cycles required. Refer Xilinx AXI I2C + * PG document and I2C specification for further details. + */ + + /* THIGH - Depends on SCL clock frequency(i2c_clk) as below */ + reg_val = (DIV_ROUND_UP(i2c->input_clk, 2 * i2c->i2c_clk)) - 7; + if (reg_val == 0) + return -EINVAL; + + xiic_setreg32(i2c, XIIC_THIGH_REG_OFFSET, reg_val - 1); + + /* TLOW - Value same as THIGH */ + xiic_setreg32(i2c, XIIC_TLOW_REG_OFFSET, reg_val - 1); + + /* TSUSTA */ + reg_val = (timing_reg_values[index].tsusta * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUSTA_REG_OFFSET, reg_val - 1); + + /* TSUSTO */ + reg_val = (timing_reg_values[index].tsusto * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUSTO_REG_OFFSET, reg_val - 1); + + /* THDSTA */ + reg_val = (timing_reg_values[index].thdsta * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_THDSTA_REG_OFFSET, reg_val - 1); + + /* TSUDAT */ + reg_val = (timing_reg_values[index].tsudat * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TSUDAT_REG_OFFSET, reg_val - 1); + + /* TBUF */ + reg_val = (timing_reg_values[index].tbuf * clk_in_mhz) / 1000; + xiic_setreg32(i2c, XIIC_TBUF_REG_OFFSET, reg_val - 1); + + /* THDDAT */ + xiic_setreg32(i2c, XIIC_THDDAT_REG_OFFSET, 1); + + return 0; } -static void xiic_reinit(struct xiic_i2c *i2c) +static int xiic_reinit(struct xiic_i2c *i2c) { + int ret; + xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK); + ret = xiic_setclk(i2c); + if (ret) + return ret; + /* Set receive Fifo depth to maximum (zero based). */ xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1); @@ -246,12 +496,17 @@ static void xiic_reinit(struct xiic_i2c *i2c) xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK); /* make sure RX fifo is empty */ - xiic_clear_rx_fifo(i2c); + ret = xiic_clear_rx_fifo(i2c); + if (ret) + return ret; /* Enable interrupts */ - xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); + if (!i2c->atomic) + xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); + + xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK); - xiic_irq_clr_en(i2c, XIIC_INTR_AAS_MASK | XIIC_INTR_ARB_LOST_MASK); + return 0; } static void xiic_deinit(struct xiic_i2c *i2c) @@ -265,29 +520,152 @@ static void xiic_deinit(struct xiic_i2c *i2c) xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK); } +static void xiic_smbus_block_read_setup(struct xiic_i2c *i2c) +{ + u8 rxmsg_len, rfd_set = 0; + + /* + * Clear the I2C_M_RECV_LEN flag to avoid setting + * message length again + */ + i2c->rx_msg->flags &= ~I2C_M_RECV_LEN; + + /* Set smbus_block_read flag to identify in isr */ + i2c->smbus_block_read = true; + + /* Read byte from rx fifo and set message length */ + rxmsg_len = xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); + + i2c->rx_msg->buf[i2c->rx_pos++] = rxmsg_len; + + /* Check if received length is valid */ + if (rxmsg_len <= I2C_SMBUS_BLOCK_MAX) { + /* Set Receive fifo depth */ + if (rxmsg_len > IIC_RX_FIFO_DEPTH) { + /* + * When Rx msg len greater than or equal to Rx fifo capacity + * Receive fifo depth should set to Rx fifo capacity minus 1 + */ + rfd_set = IIC_RX_FIFO_DEPTH - 1; + i2c->rx_msg->len = rxmsg_len + 1; + } else if ((rxmsg_len == 1) || + (rxmsg_len == 0)) { + /* + * Minimum of 3 bytes required to exit cleanly. 1 byte + * already received, Second byte is being received. Have + * to set NACK in read_rx before receiving the last byte + */ + rfd_set = 0; + i2c->rx_msg->len = SMBUS_BLOCK_READ_MIN_LEN; + } else { + /* + * When Rx msg len less than Rx fifo capacity + * Receive fifo depth should set to Rx msg len minus 2 + */ + rfd_set = rxmsg_len - 2; + i2c->rx_msg->len = rxmsg_len + 1; + } + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rfd_set); + + return; + } + + /* Invalid message length, trigger STATE_ERROR with tx_msg_len in ISR */ + i2c->tx_msg->len = 3; + i2c->smbus_block_read = false; + dev_err(i2c->adap.dev.parent, "smbus_block_read Invalid msg length\n"); +} + static void xiic_read_rx(struct xiic_i2c *i2c) { - u8 bytes_in_fifo; + u8 bytes_in_fifo, cr = 0, bytes_to_read = 0; + u32 bytes_rem = 0; int i; bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1; - dev_dbg(i2c->adap.dev.parent, "%s entry, bytes in fifo: %d, msg: %d" - ", SR: 0x%x, CR: 0x%x\n", - __func__, bytes_in_fifo, xiic_rx_space(i2c), - xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), - xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, + "%s entry, bytes in fifo: %d, rem: %d, SR: 0x%x, CR: 0x%x\n", + __func__, bytes_in_fifo, xiic_rx_space(i2c), + xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); if (bytes_in_fifo > xiic_rx_space(i2c)) bytes_in_fifo = xiic_rx_space(i2c); - for (i = 0; i < bytes_in_fifo; i++) + bytes_to_read = bytes_in_fifo; + + if (!i2c->dynamic) { + bytes_rem = xiic_rx_space(i2c) - bytes_in_fifo; + + /* Set msg length if smbus_block_read */ + if (i2c->rx_msg->flags & I2C_M_RECV_LEN) { + xiic_smbus_block_read_setup(i2c); + return; + } + + if (bytes_rem > IIC_RX_FIFO_DEPTH) { + bytes_to_read = bytes_in_fifo; + } else if (bytes_rem > 1) { + bytes_to_read = bytes_rem - 1; + } else if (bytes_rem == 1) { + bytes_to_read = 1; + /* Set NACK in CR to indicate slave transmitter */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr | + XIIC_CR_NO_ACK_MASK); + } else if (bytes_rem == 0) { + bytes_to_read = bytes_in_fifo; + + /* Generate stop on the bus if it is last message */ + if (i2c->nmsgs == 1) { + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_MSMS_MASK); + } + + /* Make TXACK=0, clean up for next transaction */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_NO_ACK_MASK); + } + } + + /* Read the fifo */ + for (i = 0; i < bytes_to_read; i++) { i2c->rx_msg->buf[i2c->rx_pos++] = xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET); + } - xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, - (xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ? - IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1); + if (i2c->dynamic) { + u8 bytes; + + /* Receive remaining bytes if less than fifo depth */ + bytes = min_t(u8, xiic_rx_space(i2c), IIC_RX_FIFO_DEPTH); + bytes--; + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, bytes); + } +} + +static bool xiic_error_check(struct xiic_i2c *i2c) +{ + bool status = false; + u32 pend, isr, ier; + + isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); + ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); + pend = isr & ier; + + if ((pend & XIIC_INTR_ARB_LOST_MASK) || + ((pend & XIIC_INTR_TX_ERROR_MASK) && + !(pend & XIIC_INTR_RX_FULL_MASK))) { + xiic_reinit(i2c); + status = true; + if (i2c->tx_msg || i2c->rx_msg) + i2c->atomic_xfer_state = STATE_ERROR; + } + return status; } static int xiic_tx_fifo_space(struct xiic_i2c *i2c) @@ -303,58 +681,83 @@ static void xiic_fill_tx_fifo(struct xiic_i2c *i2c) len = (len > fifo_space) ? fifo_space : len; - dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n", - __func__, len, fifo_space); + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n", + __func__, len, fifo_space); while (len--) { u16 data = i2c->tx_msg->buf[i2c->tx_pos++]; - if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) { + + if (!xiic_tx_space(i2c) && i2c->nmsgs == 1) { /* last message in transfer -> STOP */ - data |= XIIC_TX_DYN_STOP_MASK; - dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); + if (i2c->dynamic) { + data |= XIIC_TX_DYN_STOP_MASK; + } else { + u8 cr; + int status; + + /* Wait till FIFO is empty so STOP is sent last */ + status = xiic_wait_tx_empty(i2c); + if (status) + return; + + /* Write to CR to stop */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_MSMS_MASK); + } + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__); } xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); + + if (i2c->atomic && xiic_error_check(i2c)) + return; } } -static void xiic_wakeup(struct xiic_i2c *i2c, int code) +static void xiic_wakeup(struct xiic_i2c *i2c, enum xilinx_i2c_state code) { i2c->tx_msg = NULL; i2c->rx_msg = NULL; i2c->nmsgs = 0; i2c->state = code; - wake_up(&i2c->wait); + complete(&i2c->completion); } -static void xiic_process(struct xiic_i2c *i2c) +static irqreturn_t xiic_process(int irq, void *dev_id) { + struct xiic_i2c *i2c = dev_id; u32 pend, isr, ier; u32 clr = 0; + int xfer_more = 0; + int wakeup_req = 0; + enum xilinx_i2c_state wakeup_code = STATE_DONE; + int ret; /* Get the interrupt Status from the IPIF. There is no clearing of * interrupts in the IPIF. Interrupts must be cleared at the source. * To find which interrupts are pending; AND interrupts pending with * interrupts masked. */ + mutex_lock(&i2c->lock); isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET); ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET); pend = isr & ier; - dev_dbg(i2c->adap.dev.parent, "%s entry, IER: 0x%x, ISR: 0x%x, " - "pend: 0x%x, SR: 0x%x, msg: %p, nmsgs: %d\n", - __func__, ier, isr, pend, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), + dev_dbg(i2c->adap.dev.parent, "%s: IER: 0x%x, ISR: 0x%x, pend: 0x%x\n", + __func__, ier, isr, pend); + dev_dbg(i2c->adap.dev.parent, "%s: SR: 0x%x, msg: %p, nmsgs: %d\n", + __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET), i2c->tx_msg, i2c->nmsgs); - - /* Do not processes a devices interrupts if the device has no - * interrupts pending - */ - if (!pend) - return; + dev_dbg(i2c->adap.dev.parent, "%s, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); /* Service requesting interrupt */ if ((pend & XIIC_INTR_ARB_LOST_MASK) || - ((pend & XIIC_INTR_TX_ERROR_MASK) && - !(pend & XIIC_INTR_RX_FULL_MASK))) { + ((pend & XIIC_INTR_TX_ERROR_MASK) && + !(pend & XIIC_INTR_RX_FULL_MASK))) { /* bus arbritration lost, or... * Transmit error _OR_ RX completed * if this happens when RX_FULL is not set @@ -367,18 +770,28 @@ static void xiic_process(struct xiic_i2c *i2c) * fifos and the next message is a TX with len 0 (only addr) * reset the IP instead of just flush fifos */ - xiic_reinit(i2c); + ret = xiic_reinit(i2c); + if (ret < 0) + dev_dbg(i2c->adap.dev.parent, "reinit failed\n"); - if (i2c->tx_msg) - xiic_wakeup(i2c, STATE_ERROR); - - } else if (pend & XIIC_INTR_RX_FULL_MASK) { + if (i2c->rx_msg) { + wakeup_req = 1; + wakeup_code = STATE_ERROR; + } + if (i2c->tx_msg) { + wakeup_req = 1; + wakeup_code = STATE_ERROR; + } + /* don't try to handle other events */ + goto out; + } + if (pend & XIIC_INTR_RX_FULL_MASK) { /* Receive register/FIFO is full */ - clr = XIIC_INTR_RX_FULL_MASK; + clr |= XIIC_INTR_RX_FULL_MASK; if (!i2c->rx_msg) { dev_dbg(i2c->adap.dev.parent, - "%s unexpexted RX IRQ\n", __func__); + "%s unexpected RX IRQ\n", __func__); xiic_clear_rx_fifo(i2c); goto out; } @@ -404,49 +817,36 @@ static void xiic_process(struct xiic_i2c *i2c) i2c->tx_msg++; dev_dbg(i2c->adap.dev.parent, "%s will start next...\n", __func__); - - __xiic_start_xfer(i2c); + xfer_more = 1; } } - } else if (pend & XIIC_INTR_BNB_MASK) { - /* IIC bus has transitioned to not busy */ - clr = XIIC_INTR_BNB_MASK; - - /* The bus is not busy, disable BusNotBusy interrupt */ - xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK); - - if (!i2c->tx_msg) - goto out; - - if ((i2c->nmsgs == 1) && !i2c->rx_msg && - xiic_tx_space(i2c) == 0) - xiic_wakeup(i2c, STATE_DONE); - else - xiic_wakeup(i2c, STATE_ERROR); - - } else if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { + } + if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) { /* Transmit register/FIFO is empty or ½ empty */ - clr = pend & - (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK); + clr |= (pend & + (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)); if (!i2c->tx_msg) { dev_dbg(i2c->adap.dev.parent, - "%s unexpexted TX IRQ\n", __func__); + "%s unexpected TX IRQ\n", __func__); goto out; } - xiic_fill_tx_fifo(i2c); - - /* current message sent and there is space in the fifo */ - if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) { + if (xiic_tx_space(i2c)) { + xiic_fill_tx_fifo(i2c); + } else { + /* current message fully written */ dev_dbg(i2c->adap.dev.parent, "%s end of message sent, nmsgs: %d\n", __func__, i2c->nmsgs); - if (i2c->nmsgs > 1) { + /* Don't move onto the next message until the TX FIFO empties, + * to ensure that a NAK is not missed. + */ + if (i2c->nmsgs > 1 && (pend & XIIC_INTR_TX_EMPTY_MASK)) { i2c->nmsgs--; i2c->tx_msg++; - __xiic_start_xfer(i2c); + xfer_more = 1; } else { xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); @@ -454,21 +854,47 @@ static void xiic_process(struct xiic_i2c *i2c) "%s Got TX IRQ but no more to do...\n", __func__); } - } else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1)) - /* current frame is sent and is last, - * make sure to disable tx half - */ - xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); - } else { - /* got IRQ which is not acked */ - dev_err(i2c->adap.dev.parent, "%s Got unexpected IRQ\n", - __func__); - clr = pend; + } } + + if (pend & XIIC_INTR_BNB_MASK) { + /* IIC bus has transitioned to not busy */ + clr |= XIIC_INTR_BNB_MASK; + + /* The bus is not busy, disable BusNotBusy interrupt */ + xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK); + + if (i2c->tx_msg && i2c->smbus_block_read) { + i2c->smbus_block_read = false; + /* Set requested message len=1 to indicate STATE_DONE */ + i2c->tx_msg->len = 1; + } + + if (!i2c->tx_msg) + goto out; + + wakeup_req = 1; + + if (i2c->nmsgs == 1 && !i2c->rx_msg && + xiic_tx_space(i2c) == 0) + wakeup_code = STATE_DONE; + else + wakeup_code = STATE_ERROR; + } + out: dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr); xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr); + if (xfer_more) + __xiic_start_xfer(i2c); + if (wakeup_req) + xiic_wakeup(i2c, wakeup_code); + + WARN_ON(xfer_more && wakeup_req); + + mutex_unlock(&i2c->lock); + return IRQ_HANDLED; } static int xiic_bus_busy(struct xiic_i2c *i2c) @@ -478,167 +904,420 @@ static int xiic_bus_busy(struct xiic_i2c *i2c) return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0; } -static int xiic_busy(struct xiic_i2c *i2c) +static int xiic_wait_not_busy(struct xiic_i2c *i2c) { int tries = 3; int err; - if (i2c->tx_msg) - return -EBUSY; - /* for instance if previous transfer was terminated due to TX error * it might be that the bus is on it's way to become available * give it at most 3 ms to wake */ err = xiic_bus_busy(i2c); while (err && tries--) { - mdelay(1); + if (i2c->atomic) + udelay(1000); + else + usleep_range(1000, 1100); err = xiic_bus_busy(i2c); } return err; } +static void xiic_recv_atomic(struct xiic_i2c *i2c) +{ + while (xiic_rx_space(i2c)) { + if (xiic_getreg32(i2c, XIIC_IISR_OFFSET) & XIIC_INTR_RX_FULL_MASK) { + xiic_read_rx(i2c); + + /* Clear Rx full and Tx error interrupts. */ + xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | + XIIC_INTR_TX_ERROR_MASK); + } + if (xiic_error_check(i2c)) + return; + } + + i2c->rx_msg = NULL; + xiic_irq_clr_en(i2c, XIIC_INTR_TX_ERROR_MASK); + + /* send next message if this wasn't the last. */ + if (i2c->nmsgs > 1) { + i2c->nmsgs--; + i2c->tx_msg++; + __xiic_start_xfer(i2c); + } +} + static void xiic_start_recv(struct xiic_i2c *i2c) { - u8 rx_watermark; + u16 rx_watermark; + u8 cr = 0, rfd_set = 0; struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg; - /* Clear and enable Rx full interrupt. */ - xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK); + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + + /* Disable Tx interrupts */ + xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK | XIIC_INTR_TX_EMPTY_MASK); + + if (i2c->dynamic) { + u8 bytes; + u16 val; + + /* Clear and enable Rx full interrupt. */ + xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | + XIIC_INTR_TX_ERROR_MASK); + + /* + * We want to get all but last byte, because the TX_ERROR IRQ + * is used to indicate error ACK on the address, and + * negative ack on the last received byte, so to not mix + * them receive all but last. + * In the case where there is only one byte to receive + * we can check if ERROR and RX full is set at the same time + */ + rx_watermark = msg->len; + bytes = min_t(u8, rx_watermark, IIC_RX_FIFO_DEPTH); - /* we want to get all but last byte, because the TX_ERROR IRQ is used - * to inidicate error ACK on the address, and negative ack on the last - * received byte, so to not mix them receive all but last. - * In the case where there is only one byte to receive - * we can check if ERROR and RX full is set at the same time - */ - rx_watermark = msg->len; - if (rx_watermark > IIC_RX_FIFO_DEPTH) - rx_watermark = IIC_RX_FIFO_DEPTH; - xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1); + if (rx_watermark > 0) + bytes--; + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, bytes); - if (!(msg->flags & I2C_M_NOSTART)) /* write the address */ xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, - (msg->addr << 1) | XIIC_READ_OPERATION | - XIIC_TX_DYN_START_MASK); + i2c_8bit_addr_from_msg(msg) | + XIIC_TX_DYN_START_MASK); + + /* If last message, include dynamic stop bit with length */ + val = (i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0; + val |= msg->len; + + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, val); - xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); + xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); + } else { + /* + * If previous message is Tx, make sure that Tx FIFO is empty + * before starting a new transfer as the repeated start in + * standard mode can corrupt the transaction if there are + * still bytes to be transmitted in FIFO + */ + if (i2c->prev_msg_tx) { + int status; + + status = xiic_wait_tx_empty(i2c); + if (status) + return; + } + + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + + /* Set Receive fifo depth */ + rx_watermark = msg->len; + if (rx_watermark > IIC_RX_FIFO_DEPTH) { + rfd_set = IIC_RX_FIFO_DEPTH - 1; + } else if (rx_watermark == 1) { + rfd_set = rx_watermark - 1; + + /* Set No_ACK, except for smbus_block_read */ + if (!(i2c->rx_msg->flags & I2C_M_RECV_LEN)) { + /* Handle single byte transfer separately */ + cr |= XIIC_CR_NO_ACK_MASK; + } + } else if (rx_watermark == 0) { + rfd_set = rx_watermark; + } else { + rfd_set = rx_watermark - 2; + } + /* Check if RSTA should be set */ + if (cr & XIIC_CR_MSMS_MASK) { + /* Already a master, RSTA should be set */ + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_REPEATED_START_MASK) & + ~(XIIC_CR_DIR_IS_TX_MASK)); + } + + xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rfd_set); + + /* Clear and enable Rx full and transmit complete interrupts */ + xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | + XIIC_INTR_TX_ERROR_MASK); + + /* Write the address */ + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, + i2c_8bit_addr_from_msg(msg)); + + /* Write to Control Register,to start transaction in Rx mode */ + if ((cr & XIIC_CR_MSMS_MASK) == 0) { + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_MSMS_MASK) + & ~(XIIC_CR_DIR_IS_TX_MASK)); + } + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, "%s end, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + } - xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, - msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0)); if (i2c->nmsgs == 1) /* very last, enable bus not busy as well */ xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK); /* the message is tx:ed */ i2c->tx_pos = msg->len; + + i2c->prev_msg_tx = false; + + /* Enable interrupts */ + if (!i2c->atomic) + xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); + else + xiic_recv_atomic(i2c); +} + +static void xiic_send_rem_atomic(struct xiic_i2c *i2c) +{ + while (xiic_tx_space(i2c)) { + if (xiic_tx_fifo_space(i2c)) { + u16 data; + + data = i2c->tx_msg->buf[i2c->tx_pos]; + i2c->tx_pos++; + if (!xiic_tx_space(i2c) && i2c->nmsgs == 1) { + /* last message in transfer -> STOP */ + if (i2c->dynamic) { + data |= XIIC_TX_DYN_STOP_MASK; + } else { + u8 cr; + int status; + + /* Wait till FIFO is empty so STOP is sent last */ + status = xiic_wait_tx_empty(i2c); + if (status) + return; + + /* Write to CR to stop */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & + ~XIIC_CR_MSMS_MASK); + } + } + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); + } + if (xiic_error_check(i2c)) + return; + } + + if (i2c->nmsgs > 1) { + i2c->nmsgs--; + i2c->tx_msg++; + __xiic_start_xfer(i2c); + } else { + xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK); + } } static void xiic_start_send(struct xiic_i2c *i2c) { + u8 cr = 0; + u16 data; struct i2c_msg *msg = i2c->tx_msg; - xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK); - - dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d, " - "ISR: 0x%x, CR: 0x%x\n", - __func__, msg, msg->len, xiic_getreg32(i2c, XIIC_IISR_OFFSET), - xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + if (!i2c->atomic) { + dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d", + __func__, msg, msg->len); + dev_dbg(i2c->adap.dev.parent, "%s entry, ISR: 0x%x, CR: 0x%x\n", + __func__, xiic_getreg32(i2c, XIIC_IISR_OFFSET), + xiic_getreg8(i2c, XIIC_CR_REG_OFFSET)); + } - if (!(msg->flags & I2C_M_NOSTART)) { + if (i2c->dynamic) { /* write the address */ - u16 data = ((msg->addr << 1) & 0xfe) | XIIC_WRITE_OPERATION | - XIIC_TX_DYN_START_MASK; - if ((i2c->nmsgs == 1) && msg->len == 0) + data = i2c_8bit_addr_from_msg(msg) | + XIIC_TX_DYN_START_MASK; + + if (i2c->nmsgs == 1 && msg->len == 0) /* no data and last message -> add STOP */ data |= XIIC_TX_DYN_STOP_MASK; xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); - } - xiic_fill_tx_fifo(i2c); + /* Clear any pending Tx empty, Tx Error and then enable them */ + xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | + XIIC_INTR_TX_ERROR_MASK | + XIIC_INTR_BNB_MASK | + ((i2c->nmsgs > 1 || xiic_tx_space(i2c)) ? + XIIC_INTR_TX_HALF_MASK : 0)); - /* Clear any pending Tx empty, Tx Error and then enable them. */ - xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK | - XIIC_INTR_BNB_MASK); -} + xiic_fill_tx_fifo(i2c); + } else { + /* + * If previous message is Tx, make sure that Tx FIFO is empty + * before starting a new transfer as the repeated start in + * standard mode can corrupt the transaction if there are + * still bytes to be transmitted in FIFO + */ + if (i2c->prev_msg_tx) { + int status; -static irqreturn_t xiic_isr(int irq, void *dev_id) -{ - struct xiic_i2c *i2c = dev_id; + status = xiic_wait_tx_empty(i2c); + if (status) + return; + } + /* Check if RSTA should be set */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + if (cr & XIIC_CR_MSMS_MASK) { + /* Already a master, RSTA should be set */ + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, (cr | + XIIC_CR_REPEATED_START_MASK | + XIIC_CR_DIR_IS_TX_MASK) & + ~(XIIC_CR_NO_ACK_MASK)); + } - spin_lock(&i2c->lock); - /* disable interrupts globally */ - xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0); + /* Write address to FIFO */ + data = i2c_8bit_addr_from_msg(msg); + xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data); - dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__); + /* Fill fifo */ + xiic_fill_tx_fifo(i2c); - xiic_process(i2c); + if ((cr & XIIC_CR_MSMS_MASK) == 0) { + /* Start Tx by writing to CR */ + cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET); + xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr | + XIIC_CR_MSMS_MASK | + XIIC_CR_DIR_IS_TX_MASK); + } - xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); - spin_unlock(&i2c->lock); + /* Clear any pending Tx empty, Tx Error and then enable them */ + xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | + XIIC_INTR_TX_ERROR_MASK | + XIIC_INTR_BNB_MASK); + } - return IRQ_HANDLED; + i2c->prev_msg_tx = true; + + if (i2c->atomic && !i2c->atomic_xfer_state) + xiic_send_rem_atomic(i2c); } static void __xiic_start_xfer(struct xiic_i2c *i2c) { - int first = 1; int fifo_space = xiic_tx_fifo_space(i2c); - dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n", - __func__, i2c->tx_msg, fifo_space); + + if (!i2c->atomic) + dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n", + __func__, i2c->tx_msg, fifo_space); if (!i2c->tx_msg) return; + if (i2c->atomic && xiic_error_check(i2c)) + return; + i2c->rx_pos = 0; i2c->tx_pos = 0; i2c->state = STATE_START; - while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) { - if (!first) { - i2c->nmsgs--; - i2c->tx_msg++; - i2c->tx_pos = 0; - } else - first = 0; - - if (i2c->tx_msg->flags & I2C_M_RD) { - /* we dont date putting several reads in the FIFO */ - xiic_start_recv(i2c); - return; - } else { - xiic_start_send(i2c); - if (xiic_tx_space(i2c) != 0) { - /* the message could not be completely sent */ - break; - } - } + if (i2c->tx_msg->flags & I2C_M_RD) { + /* we dont date putting several reads in the FIFO */ + xiic_start_recv(i2c); + } else { + xiic_start_send(i2c); + } +} + +static int xiic_start_xfer(struct xiic_i2c *i2c, struct i2c_msg *msgs, int num) +{ + bool broken_read, max_read_len, smbus_blk_read; + int ret, count; - fifo_space = xiic_tx_fifo_space(i2c); + if (i2c->atomic) + spin_lock(&i2c->atomic_lock); + else + mutex_lock(&i2c->lock); + + if (i2c->tx_msg || i2c->rx_msg) { + dev_err(i2c->adap.dev.parent, + "cannot start a transfer while busy\n"); + ret = -EBUSY; + goto out; } - /* there are more messages or the current one could not be completely - * put into the FIFO, also enable the half empty interrupt + i2c->atomic_xfer_state = STATE_DONE; + + /* In single master mode bus can only be busy, when in use by this + * driver. If the register indicates bus being busy for some reason we + * should ignore it, since bus will never be released and i2c will be + * stuck forever. */ - if (i2c->nmsgs > 1 || xiic_tx_space(i2c)) - xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK); + if (!i2c->singlemaster) { + ret = xiic_wait_not_busy(i2c); + if (ret) { + /* If the bus is stuck in a busy state, such as due to spurious low + * pulses on the bus causing a false start condition to be detected, + * then try to recover by re-initializing the controller and check + * again if the bus is still busy. + */ + dev_warn(i2c->adap.dev.parent, "I2C bus busy timeout, reinitializing\n"); + ret = xiic_reinit(i2c); + if (ret) + goto out; + ret = xiic_wait_not_busy(i2c); + if (ret) + goto out; + } + } -} + i2c->tx_msg = msgs; + i2c->rx_msg = NULL; + i2c->nmsgs = num; -static void xiic_start_xfer(struct xiic_i2c *i2c) -{ - unsigned long flags; + if (!i2c->atomic) + init_completion(&i2c->completion); + + /* Decide standard mode or Dynamic mode */ + i2c->dynamic = true; + + /* Initialize prev message type */ + i2c->prev_msg_tx = false; + + /* + * Scan through nmsgs, use dynamic mode when none of the below three + * conditions occur. We need standard mode even if one condition holds + * true in the entire array of messages in a single transfer. + * If read transaction as dynamic mode is broken for delayed reads + * in xlnx,axi-iic-2.0 / xlnx,xps-iic-2.00.a IP versions. + * If read length is > 255 bytes. + * If smbus_block_read transaction. + */ + for (count = 0; count < i2c->nmsgs; count++) { + broken_read = (i2c->quirks & DYNAMIC_MODE_READ_BROKEN_BIT) && + (i2c->tx_msg[count].flags & I2C_M_RD); + max_read_len = (i2c->tx_msg[count].flags & I2C_M_RD) && + (i2c->tx_msg[count].len > MAX_READ_LENGTH_DYNAMIC); + smbus_blk_read = (i2c->tx_msg[count].flags & I2C_M_RECV_LEN); + + if (broken_read || max_read_len || smbus_blk_read) { + i2c->dynamic = false; + break; + } + } + + ret = xiic_reinit(i2c); + if (!ret) + __xiic_start_xfer(i2c); - spin_lock_irqsave(&i2c->lock, flags); - xiic_reinit(i2c); - /* disable interrupts globally */ - xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0); - spin_unlock_irqrestore(&i2c->lock, flags); +out: + if (i2c->atomic) + spin_unlock(&i2c->atomic_lock); + else + mutex_unlock(&i2c->lock); - __xiic_start_xfer(i2c); - xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK); + return ret; } static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) @@ -649,173 +1328,256 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)); - err = xiic_busy(i2c); + err = pm_runtime_resume_and_get(i2c->dev); + if (err < 0) + return err; + + err = xiic_start_xfer(i2c, msgs, num); + if (err < 0) + goto out; + + err = wait_for_completion_timeout(&i2c->completion, XIIC_XFER_TIMEOUT); + mutex_lock(&i2c->lock); + if (err == 0) { /* Timeout */ + i2c->tx_msg = NULL; + i2c->rx_msg = NULL; + i2c->nmsgs = 0; + err = -ETIMEDOUT; + } else { + err = (i2c->state == STATE_DONE) ? num : -EIO; + } + mutex_unlock(&i2c->lock); + +out: + pm_runtime_put_autosuspend(i2c->dev); + return err; +} + +static int xiic_xfer_atomic(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) +{ + struct xiic_i2c *i2c = i2c_get_adapdata(adap); + u32 status_reg; + int err; + + err = xiic_i2c_runtime_resume(i2c->dev); if (err) return err; - i2c->tx_msg = msgs; - i2c->nmsgs = num; + i2c->atomic = true; + err = xiic_start_xfer(i2c, msgs, num); + if (err < 0) + return err; + + err = readl_poll_timeout_atomic(i2c->base + XIIC_SR_REG_OFFSET, + status_reg, !(status_reg & XIIC_SR_BUS_BUSY_MASK), + 1, XIIC_XFER_TIMEOUT_US); - xiic_start_xfer(i2c); + if (err) /* Timeout */ + err = -ETIMEDOUT; - if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || - (i2c->state == STATE_DONE), HZ)) - return (i2c->state == STATE_DONE) ? num : -EIO; - else { + spin_lock(&i2c->atomic_lock); + if (err || i2c->state) { i2c->tx_msg = NULL; i2c->rx_msg = NULL; i2c->nmsgs = 0; - return -ETIMEDOUT; } + + err = (i2c->atomic_xfer_state == STATE_DONE) ? num : -EIO; + spin_unlock(&i2c->atomic_lock); + + i2c->atomic = false; + xiic_i2c_runtime_suspend(i2c->dev); + + return err; } static u32 xiic_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; } static const struct i2c_algorithm xiic_algorithm = { - .master_xfer = xiic_xfer, - .functionality = xiic_func, + .xfer = xiic_xfer, + .xfer_atomic = xiic_xfer_atomic, + .functionality = xiic_func, }; -static struct i2c_adapter xiic_adapter = { - .owner = THIS_MODULE, - .name = DRIVER_NAME, - .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, - .algo = &xiic_algorithm, +static const struct i2c_adapter xiic_adapter = { + .owner = THIS_MODULE, + .class = I2C_CLASS_DEPRECATED, + .algo = &xiic_algorithm, }; +#if defined(CONFIG_OF) +static const struct xiic_version_data xiic_2_00 = { + .quirks = DYNAMIC_MODE_READ_BROKEN_BIT, +}; + +static const struct of_device_id xiic_of_match[] = { + { .compatible = "xlnx,xps-iic-2.00.a", .data = &xiic_2_00 }, + { .compatible = "xlnx,axi-iic-2.1", }, + {}, +}; +MODULE_DEVICE_TABLE(of, xiic_of_match); +#endif static int xiic_i2c_probe(struct platform_device *pdev) { struct xiic_i2c *i2c; struct xiic_i2c_platform_data *pdata; + const struct of_device_id *match; struct resource *res; int ret, irq; u8 i; + u32 sr; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - goto resource_missing; - - irq = platform_get_irq(pdev, 0); - if (irq < 0) - goto resource_missing; - - pdata = (struct xiic_i2c_platform_data *) pdev->dev.platform_data; - - i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); + i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; - if (!request_mem_region(res->start, resource_size(res), pdev->name)) { - dev_err(&pdev->dev, "Memory region busy\n"); - ret = -EBUSY; - goto request_mem_failed; - } + match = of_match_node(xiic_of_match, pdev->dev.of_node); + if (match && match->data) { + const struct xiic_version_data *data = match->data; - i2c->base = ioremap(res->start, resource_size(res)); - if (!i2c->base) { - dev_err(&pdev->dev, "Unable to map registers\n"); - ret = -EIO; - goto map_failed; + i2c->quirks = data->quirks; } + i2c->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(i2c->base)) + return PTR_ERR(i2c->base); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + pdata = dev_get_platdata(&pdev->dev); + /* hook up driver to tree */ platform_set_drvdata(pdev, i2c); i2c->adap = xiic_adapter; i2c_set_adapdata(&i2c->adap, i2c); i2c->adap.dev.parent = &pdev->dev; i2c->adap.dev.of_node = pdev->dev.of_node; + snprintf(i2c->adap.name, sizeof(i2c->adap.name), + DRIVER_NAME " %s", pdev->name); + + mutex_init(&i2c->lock); + spin_lock_init(&i2c->atomic_lock); + + i2c->clk = devm_clk_get_enabled(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk), + "failed to enable input clock.\n"); + + i2c->dev = &pdev->dev; + pm_runtime_set_autosuspend_delay(i2c->dev, XIIC_PM_TIMEOUT); + pm_runtime_use_autosuspend(i2c->dev); + pm_runtime_set_active(i2c->dev); + pm_runtime_enable(i2c->dev); + + /* SCL frequency configuration */ + i2c->input_clk = clk_get_rate(i2c->clk); + ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &i2c->i2c_clk); + /* If clock-frequency not specified in DT, do not configure in SW */ + if (ret || i2c->i2c_clk > I2C_MAX_FAST_MODE_PLUS_FREQ) + i2c->i2c_clk = 0; + + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, + xiic_process, IRQF_ONESHOT, + pdev->name, i2c); + + if (ret < 0) { + dev_err_probe(&pdev->dev, ret, "Cannot claim IRQ\n"); + goto err_pm_disable; + } - xiic_reinit(i2c); + i2c->singlemaster = + of_property_read_bool(pdev->dev.of_node, "single-master"); - spin_lock_init(&i2c->lock); - init_waitqueue_head(&i2c->wait); - ret = request_irq(irq, xiic_isr, 0, pdev->name, i2c); - if (ret) { - dev_err(&pdev->dev, "Cannot claim IRQ\n"); - goto request_irq_failed; + /* + * Detect endianness + * Try to reset the TX FIFO. Then check the EMPTY flag. If it is not + * set, assume that the endianness was wrong and swap. + */ + i2c->endianness = LITTLE; + xiic_setreg32(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK); + /* Reset is cleared in xiic_reinit */ + sr = xiic_getreg32(i2c, XIIC_SR_REG_OFFSET); + if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK)) + i2c->endianness = BIG; + + ret = xiic_reinit(i2c); + if (ret < 0) { + dev_err_probe(&pdev->dev, ret, "Cannot xiic_reinit\n"); + goto err_pm_disable; } /* add i2c adapter to i2c tree */ ret = i2c_add_adapter(&i2c->adap); if (ret) { - dev_err(&pdev->dev, "Failed to add adapter\n"); - goto add_adapter_failed; + xiic_deinit(i2c); + goto err_pm_disable; } if (pdata) { /* add in known devices to the bus */ for (i = 0; i < pdata->num_devices; i++) - i2c_new_device(&i2c->adap, pdata->devices + i); + i2c_new_client_device(&i2c->adap, pdata->devices + i); } - of_i2c_register_devices(&i2c->adap); + dev_dbg(&pdev->dev, "mmio %08lx irq %d scl clock frequency %d\n", + (unsigned long)res->start, irq, i2c->i2c_clk); return 0; -add_adapter_failed: - free_irq(irq, i2c); -request_irq_failed: - xiic_deinit(i2c); - iounmap(i2c->base); -map_failed: - release_mem_region(res->start, resource_size(res)); -request_mem_failed: - kfree(i2c); +err_pm_disable: + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); return ret; -resource_missing: - dev_err(&pdev->dev, "IRQ or Memory resource is missing\n"); - return -ENOENT; } -static int xiic_i2c_remove(struct platform_device *pdev) +static void xiic_i2c_remove(struct platform_device *pdev) { struct xiic_i2c *i2c = platform_get_drvdata(pdev); - struct resource *res; + int ret; /* remove adapter & data */ i2c_del_adapter(&i2c->adap); - xiic_deinit(i2c); - - free_irq(platform_get_irq(pdev, 0), i2c); - - iounmap(i2c->base); + ret = pm_runtime_get_sync(i2c->dev); - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (res) - release_mem_region(res->start, resource_size(res)); + if (ret < 0) + dev_warn(&pdev->dev, "Failed to activate device for removal (%pe)\n", + ERR_PTR(ret)); + else + xiic_deinit(i2c); - kfree(i2c); - - return 0; + pm_runtime_put_sync(i2c->dev); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_dont_use_autosuspend(&pdev->dev); } -#if defined(CONFIG_OF) -static const struct of_device_id xiic_of_match[] = { - { .compatible = "xlnx,xps-iic-2.00.a", }, - {}, +static const struct dev_pm_ops xiic_dev_pm_ops = { + SET_RUNTIME_PM_OPS(xiic_i2c_runtime_suspend, + xiic_i2c_runtime_resume, NULL) }; -MODULE_DEVICE_TABLE(of, xiic_of_match); -#endif static struct platform_driver xiic_i2c_driver = { .probe = xiic_i2c_probe, - .remove = xiic_i2c_remove, + .remove = xiic_i2c_remove, .driver = { - .owner = THIS_MODULE, .name = DRIVER_NAME, .of_match_table = of_match_ptr(xiic_of_match), + .pm = &xiic_dev_pm_ops, }, }; module_platform_driver(xiic_i2c_driver); +MODULE_ALIAS("platform:" DRIVER_NAME); MODULE_AUTHOR("info@mocean-labs.com"); MODULE_DESCRIPTION("Xilinx I2C bus driver"); MODULE_LICENSE("GPL v2"); -MODULE_ALIAS("platform:"DRIVER_NAME); |