diff options
Diffstat (limited to 'drivers/spi/spi-microchip-core.c')
| -rw-r--r-- | drivers/spi/spi-microchip-core.c | 631 |
1 files changed, 0 insertions, 631 deletions
diff --git a/drivers/spi/spi-microchip-core.c b/drivers/spi/spi-microchip-core.c deleted file mode 100644 index 5b6af55855ef..000000000000 --- a/drivers/spi/spi-microchip-core.c +++ /dev/null @@ -1,631 +0,0 @@ -// SPDX-License-Identifier: (GPL-2.0) -/* - * Microchip CoreSPI SPI controller driver - * - * Copyright (c) 2018-2022 Microchip Technology Inc. and its subsidiaries - * - * Author: Daire McNamara <daire.mcnamara@microchip.com> - * Author: Conor Dooley <conor.dooley@microchip.com> - * - */ - -#include <linux/clk.h> -#include <linux/delay.h> -#include <linux/err.h> -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/io.h> -#include <linux/module.h> -#include <linux/of.h> -#include <linux/platform_device.h> -#include <linux/spi/spi.h> - -#define MAX_LEN (0xffff) -#define MAX_CS (1) -#define DEFAULT_FRAMESIZE (8) -#define FIFO_DEPTH (32) -#define CLK_GEN_MODE1_MAX (255) -#define CLK_GEN_MODE0_MAX (15) -#define CLK_GEN_MIN (0) -#define MODE_X_MASK_SHIFT (24) - -#define CONTROL_ENABLE BIT(0) -#define CONTROL_MASTER BIT(1) -#define CONTROL_RX_DATA_INT BIT(4) -#define CONTROL_TX_DATA_INT BIT(5) -#define CONTROL_RX_OVER_INT BIT(6) -#define CONTROL_TX_UNDER_INT BIT(7) -#define CONTROL_SPO BIT(24) -#define CONTROL_SPH BIT(25) -#define CONTROL_SPS BIT(26) -#define CONTROL_FRAMEURUN BIT(27) -#define CONTROL_CLKMODE BIT(28) -#define CONTROL_BIGFIFO BIT(29) -#define CONTROL_OENOFF BIT(30) -#define CONTROL_RESET BIT(31) - -#define CONTROL_MODE_MASK GENMASK(3, 2) -#define MOTOROLA_MODE (0) -#define CONTROL_FRAMECNT_MASK GENMASK(23, 8) -#define CONTROL_FRAMECNT_SHIFT (8) - -#define STATUS_ACTIVE BIT(14) -#define STATUS_SSEL BIT(13) -#define STATUS_FRAMESTART BIT(12) -#define STATUS_TXFIFO_EMPTY_NEXT_READ BIT(11) -#define STATUS_TXFIFO_EMPTY BIT(10) -#define STATUS_TXFIFO_FULL_NEXT_WRITE BIT(9) -#define STATUS_TXFIFO_FULL BIT(8) -#define STATUS_RXFIFO_EMPTY_NEXT_READ BIT(7) -#define STATUS_RXFIFO_EMPTY BIT(6) -#define STATUS_RXFIFO_FULL_NEXT_WRITE BIT(5) -#define STATUS_RXFIFO_FULL BIT(4) -#define STATUS_TX_UNDERRUN BIT(3) -#define STATUS_RX_OVERFLOW BIT(2) -#define STATUS_RXDAT_RXED BIT(1) -#define STATUS_TXDAT_SENT BIT(0) - -#define INT_TXDONE BIT(0) -#define INT_RXRDY BIT(1) -#define INT_RX_CHANNEL_OVERFLOW BIT(2) -#define INT_TX_CHANNEL_UNDERRUN BIT(3) - -#define INT_ENABLE_MASK (CONTROL_RX_DATA_INT | CONTROL_TX_DATA_INT | \ - CONTROL_RX_OVER_INT | CONTROL_TX_UNDER_INT) - -#define REG_CONTROL (0x00) -#define REG_FRAME_SIZE (0x04) -#define FRAME_SIZE_MASK GENMASK(5, 0) -#define REG_STATUS (0x08) -#define REG_INT_CLEAR (0x0c) -#define REG_RX_DATA (0x10) -#define REG_TX_DATA (0x14) -#define REG_CLK_GEN (0x18) -#define REG_SLAVE_SELECT (0x1c) -#define SSEL_MASK GENMASK(7, 0) -#define SSEL_DIRECT BIT(8) -#define SSELOUT_SHIFT 9 -#define SSELOUT BIT(SSELOUT_SHIFT) -#define REG_MIS (0x20) -#define REG_RIS (0x24) -#define REG_CONTROL2 (0x28) -#define REG_COMMAND (0x2c) -#define COMMAND_CLRFRAMECNT BIT(4) -#define COMMAND_TXFIFORST BIT(3) -#define COMMAND_RXFIFORST BIT(2) -#define REG_PKTSIZE (0x30) -#define REG_CMD_SIZE (0x34) -#define REG_HWSTATUS (0x38) -#define REG_STAT8 (0x3c) -#define REG_CTRL2 (0x48) -#define REG_FRAMESUP (0x50) - -struct mchp_corespi { - void __iomem *regs; - struct clk *clk; - const u8 *tx_buf; - u8 *rx_buf; - u32 clk_gen; /* divider for spi output clock generated by the controller */ - u32 clk_mode; - u32 pending_slave_select; - int irq; - int tx_len; - int rx_len; - int n_bytes; -}; - -static inline u32 mchp_corespi_read(struct mchp_corespi *spi, unsigned int reg) -{ - return readl(spi->regs + reg); -} - -static inline void mchp_corespi_write(struct mchp_corespi *spi, unsigned int reg, u32 val) -{ - writel(val, spi->regs + reg); -} - -static inline void mchp_corespi_disable(struct mchp_corespi *spi) -{ - u32 control = mchp_corespi_read(spi, REG_CONTROL); - - control &= ~CONTROL_ENABLE; - - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static inline void mchp_corespi_read_fifo(struct mchp_corespi *spi) -{ - while (spi->rx_len >= spi->n_bytes && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_RXFIFO_EMPTY)) { - u32 data = mchp_corespi_read(spi, REG_RX_DATA); - - spi->rx_len -= spi->n_bytes; - - if (!spi->rx_buf) - continue; - - if (spi->n_bytes == 4) - *((u32 *)spi->rx_buf) = data; - else if (spi->n_bytes == 2) - *((u16 *)spi->rx_buf) = data; - else - *spi->rx_buf = data; - - spi->rx_buf += spi->n_bytes; - } -} - -static void mchp_corespi_enable_ints(struct mchp_corespi *spi) -{ - u32 control = mchp_corespi_read(spi, REG_CONTROL); - - control |= INT_ENABLE_MASK; - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static void mchp_corespi_disable_ints(struct mchp_corespi *spi) -{ - u32 control = mchp_corespi_read(spi, REG_CONTROL); - - control &= ~INT_ENABLE_MASK; - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static inline void mchp_corespi_set_xfer_size(struct mchp_corespi *spi, int len) -{ - u32 control; - u32 lenpart; - u32 frames = mchp_corespi_read(spi, REG_FRAMESUP); - - /* - * Writing to FRAMECNT in REG_CONTROL will reset the frame count, taking - * a shortcut requires an explicit clear. - */ - if (frames == len) { - mchp_corespi_write(spi, REG_COMMAND, COMMAND_CLRFRAMECNT); - return; - } - - /* - * The lower 16 bits of the frame count are stored in the control reg - * for legacy reasons, but the upper 16 written to a different register: - * FRAMESUP. While both the upper and lower bits can be *READ* from the - * FRAMESUP register, writing to the lower 16 bits is (supposedly) a NOP. - * - * The driver used to disable the controller while modifying the frame - * count, and mask off the lower 16 bits of len while writing to - * FRAMES_UP. When the driver was changed to disable the controller as - * infrequently as possible, it was discovered that the logic of - * lenpart = len & 0xffff_0000 - * write(REG_FRAMESUP, lenpart) - * would actually write zeros into the lower 16 bits on an mpfs250t-es, - * despite documentation stating these bits were read-only. - * Writing len unmasked into FRAMES_UP ensures those bits aren't zeroed - * on an mpfs250t-es and will be a NOP for the lower 16 bits on hardware - * that matches the documentation. - */ - lenpart = len & 0xffff; - control = mchp_corespi_read(spi, REG_CONTROL); - control &= ~CONTROL_FRAMECNT_MASK; - control |= lenpart << CONTROL_FRAMECNT_SHIFT; - mchp_corespi_write(spi, REG_CONTROL, control); - mchp_corespi_write(spi, REG_FRAMESUP, len); -} - -static inline void mchp_corespi_write_fifo(struct mchp_corespi *spi) -{ - int fifo_max, i = 0; - - fifo_max = DIV_ROUND_UP(min(spi->tx_len, FIFO_DEPTH), spi->n_bytes); - mchp_corespi_set_xfer_size(spi, fifo_max); - - while ((i < fifo_max) && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_TXFIFO_FULL)) { - u32 word; - - if (spi->n_bytes == 4) - word = spi->tx_buf ? *((u32 *)spi->tx_buf) : 0xaa; - else if (spi->n_bytes == 2) - word = spi->tx_buf ? *((u16 *)spi->tx_buf) : 0xaa; - else - word = spi->tx_buf ? *spi->tx_buf : 0xaa; - - mchp_corespi_write(spi, REG_TX_DATA, word); - if (spi->tx_buf) - spi->tx_buf += spi->n_bytes; - i++; - } - - spi->tx_len -= i * spi->n_bytes; -} - -static inline void mchp_corespi_set_framesize(struct mchp_corespi *spi, int bt) -{ - u32 frame_size = mchp_corespi_read(spi, REG_FRAME_SIZE); - u32 control; - - if ((frame_size & FRAME_SIZE_MASK) == bt) - return; - - /* - * Disable the SPI controller. Writes to the frame size have - * no effect when the controller is enabled. - */ - control = mchp_corespi_read(spi, REG_CONTROL); - control &= ~CONTROL_ENABLE; - mchp_corespi_write(spi, REG_CONTROL, control); - - mchp_corespi_write(spi, REG_FRAME_SIZE, bt); - - control |= CONTROL_ENABLE; - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static void mchp_corespi_set_cs(struct spi_device *spi, bool disable) -{ - u32 reg; - struct mchp_corespi *corespi = spi_controller_get_devdata(spi->controller); - - reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT); - reg &= ~BIT(spi_get_chipselect(spi, 0)); - reg |= !disable << spi_get_chipselect(spi, 0); - corespi->pending_slave_select = reg; - - /* - * Only deassert chip select immediately. Writing to some registers - * requires the controller to be disabled, which results in the - * output pins being tristated and can cause the SCLK and MOSI lines - * to transition. Therefore asserting the chip select is deferred - * until just before writing to the TX FIFO, to ensure the device - * doesn't see any spurious clock transitions whilst CS is enabled. - */ - if (((spi->mode & SPI_CS_HIGH) == 0) == disable) - mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg); -} - -static int mchp_corespi_setup(struct spi_device *spi) -{ - struct mchp_corespi *corespi = spi_controller_get_devdata(spi->controller); - u32 reg; - - if (spi_is_csgpiod(spi)) - return 0; - - /* - * Active high targets need to be specifically set to their inactive - * states during probe by adding them to the "control group" & thus - * driving their select line low. - */ - if (spi->mode & SPI_CS_HIGH) { - reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT); - reg |= BIT(spi_get_chipselect(spi, 0)); - corespi->pending_slave_select = reg; - mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg); - } - return 0; -} - -static void mchp_corespi_init(struct spi_controller *host, struct mchp_corespi *spi) -{ - unsigned long clk_hz; - u32 control = mchp_corespi_read(spi, REG_CONTROL); - - control &= ~CONTROL_ENABLE; - mchp_corespi_write(spi, REG_CONTROL, control); - - control |= CONTROL_MASTER; - control &= ~CONTROL_MODE_MASK; - control |= MOTOROLA_MODE; - - /* - * The controller must be configured so that it doesn't remove Chip - * Select until the entire message has been transferred, even if at - * some points TX FIFO becomes empty. - * - * BIGFIFO mode is also enabled, which sets the fifo depth to 32 frames - * for the 8 bit transfers that this driver uses. - */ - control |= CONTROL_SPS | CONTROL_BIGFIFO; - - mchp_corespi_write(spi, REG_CONTROL, control); - - mchp_corespi_set_framesize(spi, DEFAULT_FRAMESIZE); - - /* max. possible spi clock rate is the apb clock rate */ - clk_hz = clk_get_rate(spi->clk); - host->max_speed_hz = clk_hz; - - mchp_corespi_enable_ints(spi); - - /* - * It is required to enable direct mode, otherwise control over the chip - * select is relinquished to the hardware. SSELOUT is enabled too so we - * can deal with active high targets. - */ - spi->pending_slave_select = SSELOUT | SSEL_DIRECT; - mchp_corespi_write(spi, REG_SLAVE_SELECT, spi->pending_slave_select); - - control = mchp_corespi_read(spi, REG_CONTROL); - - control &= ~CONTROL_RESET; - control |= CONTROL_ENABLE; - - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static inline void mchp_corespi_set_clk_gen(struct mchp_corespi *spi) -{ - u32 control; - - control = mchp_corespi_read(spi, REG_CONTROL); - if (spi->clk_mode) - control |= CONTROL_CLKMODE; - else - control &= ~CONTROL_CLKMODE; - - mchp_corespi_write(spi, REG_CLK_GEN, spi->clk_gen); - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static inline void mchp_corespi_set_mode(struct mchp_corespi *spi, unsigned int mode) -{ - u32 mode_val; - u32 control = mchp_corespi_read(spi, REG_CONTROL); - - switch (mode & SPI_MODE_X_MASK) { - case SPI_MODE_0: - mode_val = 0; - break; - case SPI_MODE_1: - mode_val = CONTROL_SPH; - break; - case SPI_MODE_2: - mode_val = CONTROL_SPO; - break; - case SPI_MODE_3: - mode_val = CONTROL_SPH | CONTROL_SPO; - break; - } - - /* - * Disable the SPI controller. Writes to the frame protocol have - * no effect when the controller is enabled. - */ - - control &= ~CONTROL_ENABLE; - mchp_corespi_write(spi, REG_CONTROL, control); - - control &= ~(SPI_MODE_X_MASK << MODE_X_MASK_SHIFT); - control |= mode_val; - - mchp_corespi_write(spi, REG_CONTROL, control); - - control |= CONTROL_ENABLE; - mchp_corespi_write(spi, REG_CONTROL, control); -} - -static irqreturn_t mchp_corespi_interrupt(int irq, void *dev_id) -{ - struct spi_controller *host = dev_id; - struct mchp_corespi *spi = spi_controller_get_devdata(host); - u32 intfield = mchp_corespi_read(spi, REG_MIS) & 0xf; - bool finalise = false; - - /* Interrupt line may be shared and not for us at all */ - if (intfield == 0) - return IRQ_NONE; - - if (intfield & INT_TXDONE) - mchp_corespi_write(spi, REG_INT_CLEAR, INT_TXDONE); - - if (intfield & INT_RXRDY) { - mchp_corespi_write(spi, REG_INT_CLEAR, INT_RXRDY); - - if (spi->rx_len) - mchp_corespi_read_fifo(spi); - } - - if (!spi->rx_len && !spi->tx_len) - finalise = true; - - if (intfield & INT_RX_CHANNEL_OVERFLOW) { - mchp_corespi_write(spi, REG_INT_CLEAR, INT_RX_CHANNEL_OVERFLOW); - finalise = true; - dev_err(&host->dev, - "%s: RX OVERFLOW: rxlen: %d, txlen: %d\n", __func__, - spi->rx_len, spi->tx_len); - } - - if (intfield & INT_TX_CHANNEL_UNDERRUN) { - mchp_corespi_write(spi, REG_INT_CLEAR, INT_TX_CHANNEL_UNDERRUN); - finalise = true; - dev_err(&host->dev, - "%s: TX UNDERFLOW: rxlen: %d, txlen: %d\n", __func__, - spi->rx_len, spi->tx_len); - } - - if (finalise) - spi_finalize_current_transfer(host); - - return IRQ_HANDLED; -} - -static int mchp_corespi_calculate_clkgen(struct mchp_corespi *spi, - unsigned long target_hz) -{ - unsigned long clk_hz, spi_hz, clk_gen; - - clk_hz = clk_get_rate(spi->clk); - if (!clk_hz) - return -EINVAL; - spi_hz = min(target_hz, clk_hz); - - /* - * There are two possible clock modes for the controller generated - * clock's division ratio: - * CLK_MODE = 0: 1 / (2^(CLK_GEN + 1)) where CLK_GEN = 0 to 15. - * CLK_MODE = 1: 1 / (2 * CLK_GEN + 1) where CLK_GEN = 0 to 255. - * First try mode 1, fall back to 0 and if we have tried both modes and - * we /still/ can't get a good setting, we then throw the toys out of - * the pram and give up - * clk_gen is the register name for the clock divider on MPFS. - */ - clk_gen = DIV_ROUND_UP(clk_hz, 2 * spi_hz) - 1; - if (clk_gen > CLK_GEN_MODE1_MAX || clk_gen <= CLK_GEN_MIN) { - clk_gen = DIV_ROUND_UP(clk_hz, spi_hz); - clk_gen = fls(clk_gen) - 1; - - if (clk_gen > CLK_GEN_MODE0_MAX) - return -EINVAL; - - spi->clk_mode = 0; - } else { - spi->clk_mode = 1; - } - - spi->clk_gen = clk_gen; - return 0; -} - -static int mchp_corespi_transfer_one(struct spi_controller *host, - struct spi_device *spi_dev, - struct spi_transfer *xfer) -{ - struct mchp_corespi *spi = spi_controller_get_devdata(host); - int ret; - - ret = mchp_corespi_calculate_clkgen(spi, (unsigned long)xfer->speed_hz); - if (ret) { - dev_err(&host->dev, "failed to set clk_gen for target %u Hz\n", xfer->speed_hz); - return ret; - } - - mchp_corespi_set_clk_gen(spi); - - spi->tx_buf = xfer->tx_buf; - spi->rx_buf = xfer->rx_buf; - spi->tx_len = xfer->len; - spi->rx_len = xfer->len; - spi->n_bytes = roundup_pow_of_two(DIV_ROUND_UP(xfer->bits_per_word, BITS_PER_BYTE)); - - mchp_corespi_set_framesize(spi, xfer->bits_per_word); - - mchp_corespi_write(spi, REG_COMMAND, COMMAND_RXFIFORST | COMMAND_TXFIFORST); - - mchp_corespi_write(spi, REG_SLAVE_SELECT, spi->pending_slave_select); - - while (spi->tx_len) - mchp_corespi_write_fifo(spi); - - return 1; -} - -static int mchp_corespi_prepare_message(struct spi_controller *host, - struct spi_message *msg) -{ - struct spi_device *spi_dev = msg->spi; - struct mchp_corespi *spi = spi_controller_get_devdata(host); - - mchp_corespi_set_mode(spi, spi_dev->mode); - - return 0; -} - -static int mchp_corespi_probe(struct platform_device *pdev) -{ - struct spi_controller *host; - struct mchp_corespi *spi; - struct resource *res; - u32 num_cs; - int ret = 0; - - host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi)); - if (!host) - return dev_err_probe(&pdev->dev, -ENOMEM, - "unable to allocate host for SPI controller\n"); - - platform_set_drvdata(pdev, host); - - if (of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs)) - num_cs = MAX_CS; - - host->num_chipselect = num_cs; - host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; - host->use_gpio_descriptors = true; - host->setup = mchp_corespi_setup; - host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); - host->transfer_one = mchp_corespi_transfer_one; - host->prepare_message = mchp_corespi_prepare_message; - host->set_cs = mchp_corespi_set_cs; - host->dev.of_node = pdev->dev.of_node; - - spi = spi_controller_get_devdata(host); - - spi->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res); - if (IS_ERR(spi->regs)) - return PTR_ERR(spi->regs); - - spi->irq = platform_get_irq(pdev, 0); - if (spi->irq < 0) - return spi->irq; - - ret = devm_request_irq(&pdev->dev, spi->irq, mchp_corespi_interrupt, - IRQF_SHARED, dev_name(&pdev->dev), host); - if (ret) - return dev_err_probe(&pdev->dev, ret, - "could not request irq\n"); - - spi->clk = devm_clk_get_enabled(&pdev->dev, NULL); - if (IS_ERR(spi->clk)) - return dev_err_probe(&pdev->dev, PTR_ERR(spi->clk), - "could not get clk\n"); - - mchp_corespi_init(host, spi); - - ret = devm_spi_register_controller(&pdev->dev, host); - if (ret) { - mchp_corespi_disable(spi); - return dev_err_probe(&pdev->dev, ret, - "unable to register host for SPI controller\n"); - } - - dev_info(&pdev->dev, "Registered SPI controller %d\n", host->bus_num); - - return 0; -} - -static void mchp_corespi_remove(struct platform_device *pdev) -{ - struct spi_controller *host = platform_get_drvdata(pdev); - struct mchp_corespi *spi = spi_controller_get_devdata(host); - - mchp_corespi_disable_ints(spi); - mchp_corespi_disable(spi); -} - -#define MICROCHIP_SPI_PM_OPS (NULL) - -/* - * Platform driver data structure - */ - -#if defined(CONFIG_OF) -static const struct of_device_id mchp_corespi_dt_ids[] = { - { .compatible = "microchip,mpfs-spi" }, - { /* sentinel */ } -}; -MODULE_DEVICE_TABLE(of, mchp_corespi_dt_ids); -#endif - -static struct platform_driver mchp_corespi_driver = { - .probe = mchp_corespi_probe, - .driver = { - .name = "microchip-corespi", - .pm = MICROCHIP_SPI_PM_OPS, - .of_match_table = of_match_ptr(mchp_corespi_dt_ids), - }, - .remove = mchp_corespi_remove, -}; -module_platform_driver(mchp_corespi_driver); -MODULE_DESCRIPTION("Microchip coreSPI SPI controller driver"); -MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>"); -MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>"); -MODULE_LICENSE("GPL"); |