diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-microchip-corei2c.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-microchip-corei2c.c | 224 |
1 files changed, 196 insertions, 28 deletions
diff --git a/drivers/i2c/busses/i2c-microchip-corei2c.c b/drivers/i2c/busses/i2c-microchip-corei2c.c index 0b0a1c4d17ca..492bf4c34722 100644 --- a/drivers/i2c/busses/i2c-microchip-corei2c.c +++ b/drivers/i2c/busses/i2c-microchip-corei2c.c @@ -76,6 +76,8 @@ #define CORE_I2C_FREQ (0x14) #define CORE_I2C_GLITCHREG (0x18) #define CORE_I2C_SLAVE1_ADDR (0x1c) +#define CORE_I2C_SMBUS_MSG_WR (0x0) +#define CORE_I2C_SMBUS_MSG_RD (0x1) #define PCLK_DIV_960 (CTRL_CR2) #define PCLK_DIV_256 (0) @@ -93,27 +95,35 @@ * @base: pointer to register struct * @dev: device reference * @i2c_clk: clock reference for i2c input clock + * @msg_queue: pointer to the messages requiring sending * @buf: pointer to msg buffer for easier use * @msg_complete: xfer completion object * @adapter: core i2c abstraction * @msg_err: error code for completed message * @bus_clk_rate: current i2c bus clock rate * @isr_status: cached copy of local ISR status + * @total_num: total number of messages to be sent/received + * @current_num: index of the current message being sent/received * @msg_len: number of bytes transferred in msg * @addr: address of the current slave + * @restart_needed: whether or not a repeated start is required after current message */ struct mchp_corei2c_dev { void __iomem *base; struct device *dev; struct clk *i2c_clk; + struct i2c_msg *msg_queue; u8 *buf; struct completion msg_complete; struct i2c_adapter adapter; int msg_err; + int total_num; + int current_num; u32 bus_clk_rate; u32 isr_status; u16 msg_len; u8 addr; + bool restart_needed; }; static void mchp_corei2c_core_disable(struct mchp_corei2c_dev *idev) @@ -222,6 +232,47 @@ static int mchp_corei2c_fill_tx(struct mchp_corei2c_dev *idev) return 0; } +static void mchp_corei2c_next_msg(struct mchp_corei2c_dev *idev) +{ + struct i2c_msg *this_msg; + u8 ctrl; + + if (idev->current_num >= idev->total_num) { + complete(&idev->msg_complete); + return; + } + + /* + * If there's been an error, the isr needs to return control + * to the "main" part of the driver, so as not to keep sending + * messages once it completes and clears the SI bit. + */ + if (idev->msg_err) { + complete(&idev->msg_complete); + return; + } + + this_msg = idev->msg_queue++; + + if (idev->current_num < (idev->total_num - 1)) { + struct i2c_msg *next_msg = idev->msg_queue; + + idev->restart_needed = next_msg->flags & I2C_M_RD; + } else { + idev->restart_needed = false; + } + + idev->addr = i2c_8bit_addr_from_msg(this_msg); + idev->msg_len = this_msg->len; + idev->buf = this_msg->buf; + + ctrl = readb(idev->base + CORE_I2C_CTRL); + ctrl |= CTRL_STA; + writeb(ctrl, idev->base + CORE_I2C_CTRL); + + idev->current_num++; +} + static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev) { u32 status = idev->isr_status; @@ -238,8 +289,6 @@ static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev) ctrl &= ~CTRL_STA; writeb(idev->addr, idev->base + CORE_I2C_DATA); writeb(ctrl, idev->base + CORE_I2C_CTRL); - if (idev->msg_len == 0) - finished = true; break; case STATUS_M_ARB_LOST: idev->msg_err = -EAGAIN; @@ -247,10 +296,14 @@ static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev) break; case STATUS_M_SLAW_ACK: case STATUS_M_TX_DATA_ACK: - if (idev->msg_len > 0) + if (idev->msg_len > 0) { mchp_corei2c_fill_tx(idev); - else - last_byte = true; + } else { + if (idev->restart_needed) + finished = true; + else + last_byte = true; + } break; case STATUS_M_TX_DATA_NACK: case STATUS_M_SLAR_NACK: @@ -287,7 +340,7 @@ static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev) mchp_corei2c_stop(idev); if (last_byte || finished) - complete(&idev->msg_complete); + mchp_corei2c_next_msg(idev); return IRQ_HANDLED; } @@ -311,21 +364,48 @@ static irqreturn_t mchp_corei2c_isr(int irq, void *_dev) return ret; } -static int mchp_corei2c_xfer_msg(struct mchp_corei2c_dev *idev, - struct i2c_msg *msg) +static int mchp_corei2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) { - u8 ctrl; + struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap); + struct i2c_msg *this_msg = msgs; unsigned long time_left; + u8 ctrl; - idev->addr = i2c_8bit_addr_from_msg(msg); - idev->msg_len = msg->len; - idev->buf = msg->buf; + mchp_corei2c_core_enable(idev); + + /* + * The isr controls the flow of a transfer, this info needs to be saved + * to a location that it can access the queue information from. + */ + idev->restart_needed = false; + idev->msg_queue = msgs; + idev->total_num = num; + idev->current_num = 0; + + /* + * But the first entry to the isr is triggered by the start in this + * function, so the first message needs to be "dequeued". + */ + idev->addr = i2c_8bit_addr_from_msg(this_msg); + idev->msg_len = this_msg->len; + idev->buf = this_msg->buf; idev->msg_err = 0; - reinit_completion(&idev->msg_complete); + if (idev->total_num > 1) { + struct i2c_msg *next_msg = msgs + 1; - mchp_corei2c_core_enable(idev); + idev->restart_needed = next_msg->flags & I2C_M_RD; + } + + idev->current_num++; + idev->msg_queue++; + reinit_completion(&idev->msg_complete); + + /* + * Send the first start to pass control to the isr + */ ctrl = readb(idev->base + CORE_I2C_CTRL); ctrl |= CTRL_STA; writeb(ctrl, idev->base + CORE_I2C_CTRL); @@ -335,32 +415,120 @@ static int mchp_corei2c_xfer_msg(struct mchp_corei2c_dev *idev, if (!time_left) return -ETIMEDOUT; - return idev->msg_err; + if (idev->msg_err) + return idev->msg_err; + + return num; } -static int mchp_corei2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, - int num) +static u32 mchp_corei2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static int mchp_corei2c_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags, + char read_write, u8 command, + int size, union i2c_smbus_data *data) { + struct i2c_msg msgs[2]; struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap); - int i, ret; + u8 tx_buf[I2C_SMBUS_BLOCK_MAX + 2]; + u8 rx_buf[I2C_SMBUS_BLOCK_MAX + 1]; + int num_msgs = 1; + + msgs[CORE_I2C_SMBUS_MSG_WR].addr = addr; + msgs[CORE_I2C_SMBUS_MSG_WR].flags = 0; - for (i = 0; i < num; i++) { - ret = mchp_corei2c_xfer_msg(idev, msgs++); - if (ret) - return ret; + if (read_write == I2C_SMBUS_READ && size <= I2C_SMBUS_BYTE) + msgs[CORE_I2C_SMBUS_MSG_WR].flags = I2C_M_RD; + + if (read_write == I2C_SMBUS_WRITE && size <= I2C_SMBUS_WORD_DATA) + msgs[CORE_I2C_SMBUS_MSG_WR].len = size; + + if (read_write == I2C_SMBUS_WRITE && size > I2C_SMBUS_BYTE) { + msgs[CORE_I2C_SMBUS_MSG_WR].buf = tx_buf; + msgs[CORE_I2C_SMBUS_MSG_WR].buf[0] = command; } - return num; -} + if (read_write == I2C_SMBUS_READ && size >= I2C_SMBUS_BYTE_DATA) { + msgs[CORE_I2C_SMBUS_MSG_WR].buf = tx_buf; + msgs[CORE_I2C_SMBUS_MSG_WR].buf[0] = command; + msgs[CORE_I2C_SMBUS_MSG_RD].addr = addr; + msgs[CORE_I2C_SMBUS_MSG_RD].flags = I2C_M_RD; + num_msgs = 2; + } -static u32 mchp_corei2c_func(struct i2c_adapter *adap) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + if (read_write == I2C_SMBUS_READ && size > I2C_SMBUS_QUICK) + msgs[CORE_I2C_SMBUS_MSG_WR].len = 1; + + switch (size) { + case I2C_SMBUS_QUICK: + msgs[CORE_I2C_SMBUS_MSG_WR].buf = NULL; + return 0; + case I2C_SMBUS_BYTE: + if (read_write == I2C_SMBUS_WRITE) + msgs[CORE_I2C_SMBUS_MSG_WR].buf = &command; + else + msgs[CORE_I2C_SMBUS_MSG_WR].buf = &data->byte; + break; + case I2C_SMBUS_BYTE_DATA: + if (read_write == I2C_SMBUS_WRITE) { + msgs[CORE_I2C_SMBUS_MSG_WR].buf[1] = data->byte; + } else { + msgs[CORE_I2C_SMBUS_MSG_RD].len = size - 1; + msgs[CORE_I2C_SMBUS_MSG_RD].buf = &data->byte; + } + break; + case I2C_SMBUS_WORD_DATA: + if (read_write == I2C_SMBUS_WRITE) { + msgs[CORE_I2C_SMBUS_MSG_WR].buf[1] = data->word & 0xFF; + msgs[CORE_I2C_SMBUS_MSG_WR].buf[2] = (data->word >> 8) & 0xFF; + } else { + msgs[CORE_I2C_SMBUS_MSG_RD].len = size - 1; + msgs[CORE_I2C_SMBUS_MSG_RD].buf = rx_buf; + } + break; + case I2C_SMBUS_BLOCK_DATA: + if (read_write == I2C_SMBUS_WRITE) { + int data_len; + + data_len = data->block[0]; + msgs[CORE_I2C_SMBUS_MSG_WR].len = data_len + 2; + for (int i = 0; i <= data_len; i++) + msgs[CORE_I2C_SMBUS_MSG_WR].buf[i + 1] = data->block[i]; + } else { + msgs[CORE_I2C_SMBUS_MSG_RD].len = I2C_SMBUS_BLOCK_MAX + 1; + msgs[CORE_I2C_SMBUS_MSG_RD].buf = rx_buf; + } + break; + default: + return -EOPNOTSUPP; + } + + mchp_corei2c_xfer(&idev->adapter, msgs, num_msgs); + if (read_write == I2C_SMBUS_WRITE || size <= I2C_SMBUS_BYTE_DATA) + return 0; + + switch (size) { + case I2C_SMBUS_WORD_DATA: + data->word = (rx_buf[0] | (rx_buf[1] << 8)); + break; + case I2C_SMBUS_BLOCK_DATA: + if (rx_buf[0] > I2C_SMBUS_BLOCK_MAX) + rx_buf[0] = I2C_SMBUS_BLOCK_MAX; + /* As per protocol first member of block is size of the block. */ + for (int i = 0; i <= rx_buf[0]; i++) + data->block[i] = rx_buf[i]; + break; + } + + return 0; } static const struct i2c_algorithm mchp_corei2c_algo = { .master_xfer = mchp_corei2c_xfer, .functionality = mchp_corei2c_func, + .smbus_xfer = mchp_corei2c_smbus_xfer, }; static int mchp_corei2c_probe(struct platform_device *pdev) @@ -462,7 +630,7 @@ MODULE_DEVICE_TABLE(of, mchp_corei2c_of_match); static struct platform_driver mchp_corei2c_driver = { .probe = mchp_corei2c_probe, - .remove_new = mchp_corei2c_remove, + .remove = mchp_corei2c_remove, .driver = { .name = "microchip-corei2c", .of_match_table = mchp_corei2c_of_match, |