diff options
Diffstat (limited to 'drivers/spi/spi-stm32.c')
| -rw-r--r-- | drivers/spi/spi-stm32.c | 2105 |
1 files changed, 2105 insertions, 0 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c new file mode 100644 index 000000000..9ec37cf10 --- /dev/null +++ b/drivers/spi/spi-stm32.c @@ -0,0 +1,2105 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// STMicroelectronics STM32 SPI Controller driver (master mode only) +// +// Copyright (C) 2017, STMicroelectronics - All Rights Reserved +// Author(s): Amelie Delaunay <amelie.delaunay@st.com> for STMicroelectronics. + +#include <linux/debugfs.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/pinctrl/consumer.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> +#include <linux/spi/spi.h> + +#define DRIVER_NAME "spi_stm32" + +/* STM32F4 SPI registers */ +#define STM32F4_SPI_CR1 0x00 +#define STM32F4_SPI_CR2 0x04 +#define STM32F4_SPI_SR 0x08 +#define STM32F4_SPI_DR 0x0C +#define STM32F4_SPI_I2SCFGR 0x1C + +/* STM32F4_SPI_CR1 bit fields */ +#define STM32F4_SPI_CR1_CPHA BIT(0) +#define STM32F4_SPI_CR1_CPOL BIT(1) +#define STM32F4_SPI_CR1_MSTR BIT(2) +#define STM32F4_SPI_CR1_BR_SHIFT 3 +#define STM32F4_SPI_CR1_BR GENMASK(5, 3) +#define STM32F4_SPI_CR1_SPE BIT(6) +#define STM32F4_SPI_CR1_LSBFRST BIT(7) +#define STM32F4_SPI_CR1_SSI BIT(8) +#define STM32F4_SPI_CR1_SSM BIT(9) +#define STM32F4_SPI_CR1_RXONLY BIT(10) +#define STM32F4_SPI_CR1_DFF BIT(11) +#define STM32F4_SPI_CR1_CRCNEXT BIT(12) +#define STM32F4_SPI_CR1_CRCEN BIT(13) +#define STM32F4_SPI_CR1_BIDIOE BIT(14) +#define STM32F4_SPI_CR1_BIDIMODE BIT(15) +#define STM32F4_SPI_CR1_BR_MIN 0 +#define STM32F4_SPI_CR1_BR_MAX (GENMASK(5, 3) >> 3) + +/* STM32F4_SPI_CR2 bit fields */ +#define STM32F4_SPI_CR2_RXDMAEN BIT(0) +#define STM32F4_SPI_CR2_TXDMAEN BIT(1) +#define STM32F4_SPI_CR2_SSOE BIT(2) +#define STM32F4_SPI_CR2_FRF BIT(4) +#define STM32F4_SPI_CR2_ERRIE BIT(5) +#define STM32F4_SPI_CR2_RXNEIE BIT(6) +#define STM32F4_SPI_CR2_TXEIE BIT(7) + +/* STM32F4_SPI_SR bit fields */ +#define STM32F4_SPI_SR_RXNE BIT(0) +#define STM32F4_SPI_SR_TXE BIT(1) +#define STM32F4_SPI_SR_CHSIDE BIT(2) +#define STM32F4_SPI_SR_UDR BIT(3) +#define STM32F4_SPI_SR_CRCERR BIT(4) +#define STM32F4_SPI_SR_MODF BIT(5) +#define STM32F4_SPI_SR_OVR BIT(6) +#define STM32F4_SPI_SR_BSY BIT(7) +#define STM32F4_SPI_SR_FRE BIT(8) + +/* STM32F4_SPI_I2SCFGR bit fields */ +#define STM32F4_SPI_I2SCFGR_I2SMOD BIT(11) + +/* STM32F4 SPI Baud Rate min/max divisor */ +#define STM32F4_SPI_BR_DIV_MIN (2 << STM32F4_SPI_CR1_BR_MIN) +#define STM32F4_SPI_BR_DIV_MAX (2 << STM32F4_SPI_CR1_BR_MAX) + +/* STM32H7 SPI registers */ +#define STM32H7_SPI_CR1 0x00 +#define STM32H7_SPI_CR2 0x04 +#define STM32H7_SPI_CFG1 0x08 +#define STM32H7_SPI_CFG2 0x0C +#define STM32H7_SPI_IER 0x10 +#define STM32H7_SPI_SR 0x14 +#define STM32H7_SPI_IFCR 0x18 +#define STM32H7_SPI_TXDR 0x20 +#define STM32H7_SPI_RXDR 0x30 +#define STM32H7_SPI_I2SCFGR 0x50 + +/* STM32H7_SPI_CR1 bit fields */ +#define STM32H7_SPI_CR1_SPE BIT(0) +#define STM32H7_SPI_CR1_MASRX BIT(8) +#define STM32H7_SPI_CR1_CSTART BIT(9) +#define STM32H7_SPI_CR1_CSUSP BIT(10) +#define STM32H7_SPI_CR1_HDDIR BIT(11) +#define STM32H7_SPI_CR1_SSI BIT(12) + +/* STM32H7_SPI_CR2 bit fields */ +#define STM32H7_SPI_CR2_TSIZE_SHIFT 0 +#define STM32H7_SPI_CR2_TSIZE GENMASK(15, 0) + +/* STM32H7_SPI_CFG1 bit fields */ +#define STM32H7_SPI_CFG1_DSIZE_SHIFT 0 +#define STM32H7_SPI_CFG1_DSIZE GENMASK(4, 0) +#define STM32H7_SPI_CFG1_FTHLV_SHIFT 5 +#define STM32H7_SPI_CFG1_FTHLV GENMASK(8, 5) +#define STM32H7_SPI_CFG1_RXDMAEN BIT(14) +#define STM32H7_SPI_CFG1_TXDMAEN BIT(15) +#define STM32H7_SPI_CFG1_MBR_SHIFT 28 +#define STM32H7_SPI_CFG1_MBR GENMASK(30, 28) +#define STM32H7_SPI_CFG1_MBR_MIN 0 +#define STM32H7_SPI_CFG1_MBR_MAX (GENMASK(30, 28) >> 28) + +/* STM32H7_SPI_CFG2 bit fields */ +#define STM32H7_SPI_CFG2_MIDI_SHIFT 4 +#define STM32H7_SPI_CFG2_MIDI GENMASK(7, 4) +#define STM32H7_SPI_CFG2_COMM_SHIFT 17 +#define STM32H7_SPI_CFG2_COMM GENMASK(18, 17) +#define STM32H7_SPI_CFG2_SP_SHIFT 19 +#define STM32H7_SPI_CFG2_SP GENMASK(21, 19) +#define STM32H7_SPI_CFG2_MASTER BIT(22) +#define STM32H7_SPI_CFG2_LSBFRST BIT(23) +#define STM32H7_SPI_CFG2_CPHA BIT(24) +#define STM32H7_SPI_CFG2_CPOL BIT(25) +#define STM32H7_SPI_CFG2_SSM BIT(26) +#define STM32H7_SPI_CFG2_AFCNTR BIT(31) + +/* STM32H7_SPI_IER bit fields */ +#define STM32H7_SPI_IER_RXPIE BIT(0) +#define STM32H7_SPI_IER_TXPIE BIT(1) +#define STM32H7_SPI_IER_DXPIE BIT(2) +#define STM32H7_SPI_IER_EOTIE BIT(3) +#define STM32H7_SPI_IER_TXTFIE BIT(4) +#define STM32H7_SPI_IER_OVRIE BIT(6) +#define STM32H7_SPI_IER_MODFIE BIT(9) +#define STM32H7_SPI_IER_ALL GENMASK(10, 0) + +/* STM32H7_SPI_SR bit fields */ +#define STM32H7_SPI_SR_RXP BIT(0) +#define STM32H7_SPI_SR_TXP BIT(1) +#define STM32H7_SPI_SR_EOT BIT(3) +#define STM32H7_SPI_SR_OVR BIT(6) +#define STM32H7_SPI_SR_MODF BIT(9) +#define STM32H7_SPI_SR_SUSP BIT(11) +#define STM32H7_SPI_SR_RXPLVL_SHIFT 13 +#define STM32H7_SPI_SR_RXPLVL GENMASK(14, 13) +#define STM32H7_SPI_SR_RXWNE BIT(15) + +/* STM32H7_SPI_IFCR bit fields */ +#define STM32H7_SPI_IFCR_ALL GENMASK(11, 3) + +/* STM32H7_SPI_I2SCFGR bit fields */ +#define STM32H7_SPI_I2SCFGR_I2SMOD BIT(0) + +/* STM32H7 SPI Master Baud Rate min/max divisor */ +#define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN) +#define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX) + +/* STM32H7 SPI Communication mode */ +#define STM32H7_SPI_FULL_DUPLEX 0 +#define STM32H7_SPI_SIMPLEX_TX 1 +#define STM32H7_SPI_SIMPLEX_RX 2 +#define STM32H7_SPI_HALF_DUPLEX 3 + +/* SPI Communication type */ +#define SPI_FULL_DUPLEX 0 +#define SPI_SIMPLEX_TX 1 +#define SPI_SIMPLEX_RX 2 +#define SPI_3WIRE_TX 3 +#define SPI_3WIRE_RX 4 + +#define SPI_1HZ_NS 1000000000 + +/* + * use PIO for small transfers, avoiding DMA setup/teardown overhead for drivers + * without fifo buffers. + */ +#define SPI_DMA_MIN_BYTES 16 + +/** + * struct stm32_spi_reg - stm32 SPI register & bitfield desc + * @reg: register offset + * @mask: bitfield mask + * @shift: left shift + */ +struct stm32_spi_reg { + int reg; + int mask; + int shift; +}; + +/** + * struct stm32_spi_regspec - stm32 registers definition, compatible dependent data + * @en: enable register and SPI enable bit + * @dma_rx_en: SPI DMA RX enable register end SPI DMA RX enable bit + * @dma_tx_en: SPI DMA TX enable register end SPI DMA TX enable bit + * @cpol: clock polarity register and polarity bit + * @cpha: clock phase register and phase bit + * @lsb_first: LSB transmitted first register and bit + * @br: baud rate register and bitfields + * @rx: SPI RX data register + * @tx: SPI TX data register + */ +struct stm32_spi_regspec { + const struct stm32_spi_reg en; + const struct stm32_spi_reg dma_rx_en; + const struct stm32_spi_reg dma_tx_en; + const struct stm32_spi_reg cpol; + const struct stm32_spi_reg cpha; + const struct stm32_spi_reg lsb_first; + const struct stm32_spi_reg br; + const struct stm32_spi_reg rx; + const struct stm32_spi_reg tx; +}; + +struct stm32_spi; + +/** + * struct stm32_spi_cfg - stm32 compatible configuration data + * @regs: registers descriptions + * @get_fifo_size: routine to get fifo size + * @get_bpw_mask: routine to get bits per word mask + * @disable: routine to disable controller + * @config: routine to configure controller as SPI Master + * @set_bpw: routine to configure registers to for bits per word + * @set_mode: routine to configure registers to desired mode + * @set_data_idleness: optional routine to configure registers to desired idle + * time between frames (if driver has this functionality) + * @set_number_of_data: optional routine to configure registers to desired + * number of data (if driver has this functionality) + * @can_dma: routine to determine if the transfer is eligible for DMA use + * @transfer_one_dma_start: routine to start transfer a single spi_transfer + * using DMA + * @dma_rx_cb: routine to call after DMA RX channel operation is complete + * @dma_tx_cb: routine to call after DMA TX channel operation is complete + * @transfer_one_irq: routine to configure interrupts for driver + * @irq_handler_event: Interrupt handler for SPI controller events + * @irq_handler_thread: thread of interrupt handler for SPI controller + * @baud_rate_div_min: minimum baud rate divisor + * @baud_rate_div_max: maximum baud rate divisor + * @has_fifo: boolean to know if fifo is used for driver + * @has_startbit: boolean to know if start bit is used to start transfer + */ +struct stm32_spi_cfg { + const struct stm32_spi_regspec *regs; + int (*get_fifo_size)(struct stm32_spi *spi); + int (*get_bpw_mask)(struct stm32_spi *spi); + void (*disable)(struct stm32_spi *spi); + int (*config)(struct stm32_spi *spi); + void (*set_bpw)(struct stm32_spi *spi); + int (*set_mode)(struct stm32_spi *spi, unsigned int comm_type); + void (*set_data_idleness)(struct stm32_spi *spi, u32 length); + int (*set_number_of_data)(struct stm32_spi *spi, u32 length); + void (*transfer_one_dma_start)(struct stm32_spi *spi); + void (*dma_rx_cb)(void *data); + void (*dma_tx_cb)(void *data); + int (*transfer_one_irq)(struct stm32_spi *spi); + irqreturn_t (*irq_handler_event)(int irq, void *dev_id); + irqreturn_t (*irq_handler_thread)(int irq, void *dev_id); + unsigned int baud_rate_div_min; + unsigned int baud_rate_div_max; + bool has_fifo; +}; + +/** + * struct stm32_spi - private data of the SPI controller + * @dev: driver model representation of the controller + * @master: controller master interface + * @cfg: compatible configuration data + * @base: virtual memory area + * @clk: hw kernel clock feeding the SPI clock generator + * @clk_rate: rate of the hw kernel clock feeding the SPI clock generator + * @rst: SPI controller reset line + * @lock: prevent I/O concurrent access + * @irq: SPI controller interrupt line + * @fifo_size: size of the embedded fifo in bytes + * @cur_midi: master inter-data idleness in ns + * @cur_speed: speed configured in Hz + * @cur_bpw: number of bits in a single SPI data frame + * @cur_fthlv: fifo threshold level (data frames in a single data packet) + * @cur_comm: SPI communication mode + * @cur_xferlen: current transfer length in bytes + * @cur_usedma: boolean to know if dma is used in current transfer + * @tx_buf: data to be written, or NULL + * @rx_buf: data to be read, or NULL + * @tx_len: number of data to be written in bytes + * @rx_len: number of data to be read in bytes + * @dma_tx: dma channel for TX transfer + * @dma_rx: dma channel for RX transfer + * @phys_addr: SPI registers physical base address + */ +struct stm32_spi { + struct device *dev; + struct spi_master *master; + const struct stm32_spi_cfg *cfg; + void __iomem *base; + struct clk *clk; + u32 clk_rate; + struct reset_control *rst; + spinlock_t lock; /* prevent I/O concurrent access */ + int irq; + unsigned int fifo_size; + + unsigned int cur_midi; + unsigned int cur_speed; + unsigned int cur_bpw; + unsigned int cur_fthlv; + unsigned int cur_comm; + unsigned int cur_xferlen; + bool cur_usedma; + + const void *tx_buf; + void *rx_buf; + int tx_len; + int rx_len; + struct dma_chan *dma_tx; + struct dma_chan *dma_rx; + dma_addr_t phys_addr; +}; + +static const struct stm32_spi_regspec stm32f4_spi_regspec = { + .en = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE }, + + .dma_rx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_RXDMAEN }, + .dma_tx_en = { STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN }, + + .cpol = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPOL }, + .cpha = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_CPHA }, + .lsb_first = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_LSBFRST }, + .br = { STM32F4_SPI_CR1, STM32F4_SPI_CR1_BR, STM32F4_SPI_CR1_BR_SHIFT }, + + .rx = { STM32F4_SPI_DR }, + .tx = { STM32F4_SPI_DR }, +}; + +static const struct stm32_spi_regspec stm32h7_spi_regspec = { + /* SPI data transfer is enabled but spi_ker_ck is idle. + * CFG1 and CFG2 registers are write protected when SPE is enabled. + */ + .en = { STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE }, + + .dma_rx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_RXDMAEN }, + .dma_tx_en = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN }, + + .cpol = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPOL }, + .cpha = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_CPHA }, + .lsb_first = { STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_LSBFRST }, + .br = { STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_MBR, + STM32H7_SPI_CFG1_MBR_SHIFT }, + + .rx = { STM32H7_SPI_RXDR }, + .tx = { STM32H7_SPI_TXDR }, +}; + +static inline void stm32_spi_set_bits(struct stm32_spi *spi, + u32 offset, u32 bits) +{ + writel_relaxed(readl_relaxed(spi->base + offset) | bits, + spi->base + offset); +} + +static inline void stm32_spi_clr_bits(struct stm32_spi *spi, + u32 offset, u32 bits) +{ + writel_relaxed(readl_relaxed(spi->base + offset) & ~bits, + spi->base + offset); +} + +/** + * stm32h7_spi_get_fifo_size - Return fifo size + * @spi: pointer to the spi controller data structure + */ +static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi) +{ + unsigned long flags; + u32 count = 0; + + spin_lock_irqsave(&spi->lock, flags); + + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); + + while (readl_relaxed(spi->base + STM32H7_SPI_SR) & STM32H7_SPI_SR_TXP) + writeb_relaxed(++count, spi->base + STM32H7_SPI_TXDR); + + stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); + + spin_unlock_irqrestore(&spi->lock, flags); + + dev_dbg(spi->dev, "%d x 8-bit fifo size\n", count); + + return count; +} + +/** + * stm32f4_spi_get_bpw_mask - Return bits per word mask + * @spi: pointer to the spi controller data structure + */ +static int stm32f4_spi_get_bpw_mask(struct stm32_spi *spi) +{ + dev_dbg(spi->dev, "8-bit or 16-bit data frame supported\n"); + return SPI_BPW_MASK(8) | SPI_BPW_MASK(16); +} + +/** + * stm32h7_spi_get_bpw_mask - Return bits per word mask + * @spi: pointer to the spi controller data structure + */ +static int stm32h7_spi_get_bpw_mask(struct stm32_spi *spi) +{ + unsigned long flags; + u32 cfg1, max_bpw; + + spin_lock_irqsave(&spi->lock, flags); + + /* + * The most significant bit at DSIZE bit field is reserved when the + * maximum data size of periperal instances is limited to 16-bit + */ + stm32_spi_set_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_DSIZE); + + cfg1 = readl_relaxed(spi->base + STM32H7_SPI_CFG1); + max_bpw = (cfg1 & STM32H7_SPI_CFG1_DSIZE) >> + STM32H7_SPI_CFG1_DSIZE_SHIFT; + max_bpw += 1; + + spin_unlock_irqrestore(&spi->lock, flags); + + dev_dbg(spi->dev, "%d-bit maximum data frame\n", max_bpw); + + return SPI_BPW_RANGE_MASK(4, max_bpw); +} + +/** + * stm32_spi_prepare_mbr - Determine baud rate divisor value + * @spi: pointer to the spi controller data structure + * @speed_hz: requested speed + * @min_div: minimum baud rate divisor + * @max_div: maximum baud rate divisor + * + * Return baud rate divisor value in case of success or -EINVAL + */ +static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz, + u32 min_div, u32 max_div) +{ + u32 div, mbrdiv; + + /* Ensure spi->clk_rate is even */ + div = DIV_ROUND_CLOSEST(spi->clk_rate & ~0x1, speed_hz); + + /* + * SPI framework set xfer->speed_hz to master->max_speed_hz if + * xfer->speed_hz is greater than master->max_speed_hz, and it returns + * an error when xfer->speed_hz is lower than master->min_speed_hz, so + * no need to check it there. + * However, we need to ensure the following calculations. + */ + if ((div < min_div) || (div > max_div)) + return -EINVAL; + + /* Determine the first power of 2 greater than or equal to div */ + if (div & (div - 1)) + mbrdiv = fls(div); + else + mbrdiv = fls(div) - 1; + + spi->cur_speed = spi->clk_rate / (1 << mbrdiv); + + return mbrdiv - 1; +} + +/** + * stm32h7_spi_prepare_fthlv - Determine FIFO threshold level + * @spi: pointer to the spi controller data structure + * @xfer_len: length of the message to be transferred + */ +static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len) +{ + u32 fthlv, half_fifo, packet; + + /* data packet should not exceed 1/2 of fifo space */ + half_fifo = (spi->fifo_size / 2); + + /* data_packet should not exceed transfer length */ + if (half_fifo > xfer_len) + packet = xfer_len; + else + packet = half_fifo; + + if (spi->cur_bpw <= 8) + fthlv = packet; + else if (spi->cur_bpw <= 16) + fthlv = packet / 2; + else + fthlv = packet / 4; + + /* align packet size with data registers access */ + if (spi->cur_bpw > 8) + fthlv += (fthlv % 2) ? 1 : 0; + else + fthlv += (fthlv % 4) ? (4 - (fthlv % 4)) : 0; + + if (!fthlv) + fthlv = 1; + + return fthlv; +} + +/** + * stm32f4_spi_write_tx - Write bytes to Transmit Data Register + * @spi: pointer to the spi controller data structure + * + * Read from tx_buf depends on remaining bytes to avoid to read beyond + * tx_buf end. + */ +static void stm32f4_spi_write_tx(struct stm32_spi *spi) +{ + if ((spi->tx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) & + STM32F4_SPI_SR_TXE)) { + u32 offs = spi->cur_xferlen - spi->tx_len; + + if (spi->cur_bpw == 16) { + const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs); + + writew_relaxed(*tx_buf16, spi->base + STM32F4_SPI_DR); + spi->tx_len -= sizeof(u16); + } else { + const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs); + + writeb_relaxed(*tx_buf8, spi->base + STM32F4_SPI_DR); + spi->tx_len -= sizeof(u8); + } + } + + dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len); +} + +/** + * stm32h7_spi_write_txfifo - Write bytes in Transmit Data Register + * @spi: pointer to the spi controller data structure + * + * Read from tx_buf depends on remaining bytes to avoid to read beyond + * tx_buf end. + */ +static void stm32h7_spi_write_txfifo(struct stm32_spi *spi) +{ + while ((spi->tx_len > 0) && + (readl_relaxed(spi->base + STM32H7_SPI_SR) & + STM32H7_SPI_SR_TXP)) { + u32 offs = spi->cur_xferlen - spi->tx_len; + + if (spi->tx_len >= sizeof(u32)) { + const u32 *tx_buf32 = (const u32 *)(spi->tx_buf + offs); + + writel_relaxed(*tx_buf32, spi->base + STM32H7_SPI_TXDR); + spi->tx_len -= sizeof(u32); + } else if (spi->tx_len >= sizeof(u16)) { + const u16 *tx_buf16 = (const u16 *)(spi->tx_buf + offs); + + writew_relaxed(*tx_buf16, spi->base + STM32H7_SPI_TXDR); + spi->tx_len -= sizeof(u16); + } else { + const u8 *tx_buf8 = (const u8 *)(spi->tx_buf + offs); + + writeb_relaxed(*tx_buf8, spi->base + STM32H7_SPI_TXDR); + spi->tx_len -= sizeof(u8); + } + } + + dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->tx_len); +} + +/** + * stm32f4_spi_read_rx - Read bytes from Receive Data Register + * @spi: pointer to the spi controller data structure + * + * Write in rx_buf depends on remaining bytes to avoid to write beyond + * rx_buf end. + */ +static void stm32f4_spi_read_rx(struct stm32_spi *spi) +{ + if ((spi->rx_len > 0) && (readl_relaxed(spi->base + STM32F4_SPI_SR) & + STM32F4_SPI_SR_RXNE)) { + u32 offs = spi->cur_xferlen - spi->rx_len; + + if (spi->cur_bpw == 16) { + u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs); + + *rx_buf16 = readw_relaxed(spi->base + STM32F4_SPI_DR); + spi->rx_len -= sizeof(u16); + } else { + u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs); + + *rx_buf8 = readb_relaxed(spi->base + STM32F4_SPI_DR); + spi->rx_len -= sizeof(u8); + } + } + + dev_dbg(spi->dev, "%s: %d bytes left\n", __func__, spi->rx_len); +} + +/** + * stm32h7_spi_read_rxfifo - Read bytes in Receive Data Register + * @spi: pointer to the spi controller data structure + * @flush: boolean indicating that FIFO should be flushed + * + * Write in rx_buf depends on remaining bytes to avoid to write beyond + * rx_buf end. + */ +static void stm32h7_spi_read_rxfifo(struct stm32_spi *spi, bool flush) +{ + u32 sr = readl_relaxed(spi->base + STM32H7_SPI_SR); + u32 rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >> + STM32H7_SPI_SR_RXPLVL_SHIFT; + + while ((spi->rx_len > 0) && + ((sr & STM32H7_SPI_SR_RXP) || + (flush && ((sr & STM32H7_SPI_SR_RXWNE) || (rxplvl > 0))))) { + u32 offs = spi->cur_xferlen - spi->rx_len; + + if ((spi->rx_len >= sizeof(u32)) || + (flush && (sr & STM32H7_SPI_SR_RXWNE))) { + u32 *rx_buf32 = (u32 *)(spi->rx_buf + offs); + + *rx_buf32 = readl_relaxed(spi->base + STM32H7_SPI_RXDR); + spi->rx_len -= sizeof(u32); + } else if ((spi->rx_len >= sizeof(u16)) || + (flush && (rxplvl >= 2 || spi->cur_bpw > 8))) { + u16 *rx_buf16 = (u16 *)(spi->rx_buf + offs); + + *rx_buf16 = readw_relaxed(spi->base + STM32H7_SPI_RXDR); + spi->rx_len -= sizeof(u16); + } else { + u8 *rx_buf8 = (u8 *)(spi->rx_buf + offs); + + *rx_buf8 = readb_relaxed(spi->base + STM32H7_SPI_RXDR); + spi->rx_len -= sizeof(u8); + } + + sr = readl_relaxed(spi->base + STM32H7_SPI_SR); + rxplvl = (sr & STM32H7_SPI_SR_RXPLVL) >> + STM32H7_SPI_SR_RXPLVL_SHIFT; + } + + dev_dbg(spi->dev, "%s%s: %d bytes left\n", __func__, + flush ? "(flush)" : "", spi->rx_len); +} + +/** + * stm32_spi_enable - Enable SPI controller + * @spi: pointer to the spi controller data structure + */ +static void stm32_spi_enable(struct stm32_spi *spi) +{ + dev_dbg(spi->dev, "enable controller\n"); + + stm32_spi_set_bits(spi, spi->cfg->regs->en.reg, + spi->cfg->regs->en.mask); +} + +/** + * stm32f4_spi_disable - Disable SPI controller + * @spi: pointer to the spi controller data structure + */ +static void stm32f4_spi_disable(struct stm32_spi *spi) +{ + unsigned long flags; + u32 sr; + + dev_dbg(spi->dev, "disable controller\n"); + + spin_lock_irqsave(&spi->lock, flags); + + if (!(readl_relaxed(spi->base + STM32F4_SPI_CR1) & + STM32F4_SPI_CR1_SPE)) { + spin_unlock_irqrestore(&spi->lock, flags); + return; + } + + /* Disable interrupts */ + stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXEIE | + STM32F4_SPI_CR2_RXNEIE | + STM32F4_SPI_CR2_ERRIE); + + /* Wait until BSY = 0 */ + if (readl_relaxed_poll_timeout_atomic(spi->base + STM32F4_SPI_SR, + sr, !(sr & STM32F4_SPI_SR_BSY), + 10, 100000) < 0) { + dev_warn(spi->dev, "disabling condition timeout\n"); + } + + if (spi->cur_usedma && spi->dma_tx) + dmaengine_terminate_all(spi->dma_tx); + if (spi->cur_usedma && spi->dma_rx) + dmaengine_terminate_all(spi->dma_rx); + + stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SPE); + + stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_TXDMAEN | + STM32F4_SPI_CR2_RXDMAEN); + + /* Sequence to clear OVR flag */ + readl_relaxed(spi->base + STM32F4_SPI_DR); + readl_relaxed(spi->base + STM32F4_SPI_SR); + + spin_unlock_irqrestore(&spi->lock, flags); +} + +/** + * stm32h7_spi_disable - Disable SPI controller + * @spi: pointer to the spi controller data structure + * + * RX-Fifo is flushed when SPI controller is disabled. To prevent any data + * loss, use stm32h7_spi_read_rxfifo(flush) to read the remaining bytes in + * RX-Fifo. + * Normally, if TSIZE has been configured, we should relax the hardware at the + * reception of the EOT interrupt. But in case of error, EOT will not be + * raised. So the subsystem unprepare_message call allows us to properly + * complete the transfer from an hardware point of view. + */ +static void stm32h7_spi_disable(struct stm32_spi *spi) +{ + unsigned long flags; + u32 cr1, sr; + + dev_dbg(spi->dev, "disable controller\n"); + + spin_lock_irqsave(&spi->lock, flags); + + cr1 = readl_relaxed(spi->base + STM32H7_SPI_CR1); + + if (!(cr1 & STM32H7_SPI_CR1_SPE)) { + spin_unlock_irqrestore(&spi->lock, flags); + return; + } + + /* Wait on EOT or suspend the flow */ + if (readl_relaxed_poll_timeout_atomic(spi->base + STM32H7_SPI_SR, + sr, !(sr & STM32H7_SPI_SR_EOT), + 10, 100000) < 0) { + if (cr1 & STM32H7_SPI_CR1_CSTART) { + writel_relaxed(cr1 | STM32H7_SPI_CR1_CSUSP, + spi->base + STM32H7_SPI_CR1); + if (readl_relaxed_poll_timeout_atomic( + spi->base + STM32H7_SPI_SR, + sr, !(sr & STM32H7_SPI_SR_SUSP), + 10, 100000) < 0) + dev_warn(spi->dev, + "Suspend request timeout\n"); + } + } + + if (!spi->cur_usedma && spi->rx_buf && (spi->rx_len > 0)) + stm32h7_spi_read_rxfifo(spi, true); + + if (spi->cur_usedma && spi->dma_tx) + dmaengine_terminate_all(spi->dma_tx); + if (spi->cur_usedma && spi->dma_rx) + dmaengine_terminate_all(spi->dma_rx); + + stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SPE); + + stm32_spi_clr_bits(spi, STM32H7_SPI_CFG1, STM32H7_SPI_CFG1_TXDMAEN | + STM32H7_SPI_CFG1_RXDMAEN); + + /* Disable interrupts and clear status flags */ + writel_relaxed(0, spi->base + STM32H7_SPI_IER); + writel_relaxed(STM32H7_SPI_IFCR_ALL, spi->base + STM32H7_SPI_IFCR); + + spin_unlock_irqrestore(&spi->lock, flags); +} + +/** + * stm32_spi_can_dma - Determine if the transfer is eligible for DMA use + * @master: controller master interface + * @spi_dev: pointer to the spi device + * @transfer: pointer to spi transfer + * + * If driver has fifo and the current transfer size is greater than fifo size, + * use DMA. Otherwise use DMA for transfer longer than defined DMA min bytes. + */ +static bool stm32_spi_can_dma(struct spi_master *master, + struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + unsigned int dma_size; + struct stm32_spi *spi = spi_master_get_devdata(master); + + if (spi->cfg->has_fifo) + dma_size = spi->fifo_size; + else + dma_size = SPI_DMA_MIN_BYTES; + + dev_dbg(spi->dev, "%s: %s\n", __func__, + (transfer->len > dma_size) ? "true" : "false"); + + return (transfer->len > dma_size); +} + +/** + * stm32f4_spi_irq_event - Interrupt handler for SPI controller events + * @irq: interrupt line + * @dev_id: SPI controller master interface + */ +static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id) +{ + struct spi_master *master = dev_id; + struct stm32_spi *spi = spi_master_get_devdata(master); + u32 sr, mask = 0; + bool end = false; + + spin_lock(&spi->lock); + + sr = readl_relaxed(spi->base + STM32F4_SPI_SR); + /* + * BSY flag is not handled in interrupt but it is normal behavior when + * this flag is set. + */ + sr &= ~STM32F4_SPI_SR_BSY; + + if (!spi->cur_usedma && (spi->cur_comm == SPI_SIMPLEX_TX || + spi->cur_comm == SPI_3WIRE_TX)) { + /* OVR flag shouldn't be handled for TX only mode */ + sr &= ~STM32F4_SPI_SR_OVR | STM32F4_SPI_SR_RXNE; + mask |= STM32F4_SPI_SR_TXE; + } + + if (!spi->cur_usedma && (spi->cur_comm == SPI_FULL_DUPLEX || + spi->cur_comm == SPI_SIMPLEX_RX || + spi->cur_comm == SPI_3WIRE_RX)) { + /* TXE flag is set and is handled when RXNE flag occurs */ + sr &= ~STM32F4_SPI_SR_TXE; + mask |= STM32F4_SPI_SR_RXNE | STM32F4_SPI_SR_OVR; + } + + if (!(sr & mask)) { + dev_dbg(spi->dev, "spurious IT (sr=0x%08x)\n", sr); + spin_unlock(&spi->lock); + return IRQ_NONE; + } + + if (sr & STM32F4_SPI_SR_OVR) { + dev_warn(spi->dev, "Overrun: received value discarded\n"); + + /* Sequence to clear OVR flag */ + readl_relaxed(spi->base + STM32F4_SPI_DR); + readl_relaxed(spi->base + STM32F4_SPI_SR); + + /* + * If overrun is detected, it means that something went wrong, + * so stop the current transfer. Transfer can wait for next + * RXNE but DR is already read and end never happens. + */ + end = true; + goto end_irq; + } + + if (sr & STM32F4_SPI_SR_TXE) { + if (spi->tx_buf) + stm32f4_spi_write_tx(spi); + if (spi->tx_len == 0) + end = true; + } + + if (sr & STM32F4_SPI_SR_RXNE) { + stm32f4_spi_read_rx(spi); + if (spi->rx_len == 0) + end = true; + else if (spi->tx_buf)/* Load data for discontinuous mode */ + stm32f4_spi_write_tx(spi); + } + +end_irq: + if (end) { + /* Immediately disable interrupts to do not generate new one */ + stm32_spi_clr_bits(spi, STM32F4_SPI_CR2, + STM32F4_SPI_CR2_TXEIE | + STM32F4_SPI_CR2_RXNEIE | + STM32F4_SPI_CR2_ERRIE); + spin_unlock(&spi->lock); + return IRQ_WAKE_THREAD; + } + + spin_unlock(&spi->lock); + return IRQ_HANDLED; +} + +/** + * stm32f4_spi_irq_thread - Thread of interrupt handler for SPI controller + * @irq: interrupt line + * @dev_id: SPI controller master interface + */ +static irqreturn_t stm32f4_spi_irq_thread(int irq, void *dev_id) +{ + struct spi_master *master = dev_id; + struct stm32_spi *spi = spi_master_get_devdata(master); + + spi_finalize_current_transfer(master); + stm32f4_spi_disable(spi); + + return IRQ_HANDLED; +} + +/** + * stm32h7_spi_irq_thread - Thread of interrupt handler for SPI controller + * @irq: interrupt line + * @dev_id: SPI controller master interface + */ +static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id) +{ + struct spi_master *master = dev_id; + struct stm32_spi *spi = spi_master_get_devdata(master); + u32 sr, ier, mask; + unsigned long flags; + bool end = false; + + spin_lock_irqsave(&spi->lock, flags); + + sr = readl_relaxed(spi->base + STM32H7_SPI_SR); + ier = readl_relaxed(spi->base + STM32H7_SPI_IER); + + mask = ier; + /* + * EOTIE enables irq from EOT, SUSP and TXC events. We need to set + * SUSP to acknowledge it later. TXC is automatically cleared + */ + + mask |= STM32H7_SPI_SR_SUSP; + /* + * DXPIE is set in Full-Duplex, one IT will be raised if TXP and RXP + * are set. So in case of Full-Duplex, need to poll TXP and RXP event. + */ + if ((spi->cur_comm == SPI_FULL_DUPLEX) && !spi->cur_usedma) + mask |= STM32H7_SPI_SR_TXP | STM32H7_SPI_SR_RXP; + + if (!(sr & mask)) { + dev_warn(spi->dev, "spurious IT (sr=0x%08x, ier=0x%08x)\n", + sr, ier); + spin_unlock_irqrestore(&spi->lock, flags); + return IRQ_NONE; + } + + if (sr & STM32H7_SPI_SR_SUSP) { + static DEFINE_RATELIMIT_STATE(rs, + DEFAULT_RATELIMIT_INTERVAL * 10, + 1); + ratelimit_set_flags(&rs, RATELIMIT_MSG_ON_RELEASE); + if (__ratelimit(&rs)) + dev_dbg_ratelimited(spi->dev, "Communication suspended\n"); + if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) + stm32h7_spi_read_rxfifo(spi, false); + /* + * If communication is suspended while using DMA, it means + * that something went wrong, so stop the current transfer + */ + if (spi->cur_usedma) + end = true; + } + + if (sr & STM32H7_SPI_SR_MODF) { + dev_warn(spi->dev, "Mode fault: transfer aborted\n"); + end = true; + } + + if (sr & STM32H7_SPI_SR_OVR) { + dev_err(spi->dev, "Overrun: RX data lost\n"); + end = true; + } + + if (sr & STM32H7_SPI_SR_EOT) { + if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) + stm32h7_spi_read_rxfifo(spi, true); + end = true; + } + + if (sr & STM32H7_SPI_SR_TXP) + if (!spi->cur_usedma && (spi->tx_buf && (spi->tx_len > 0))) + stm32h7_spi_write_txfifo(spi); + + if (sr & STM32H7_SPI_SR_RXP) + if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0))) + stm32h7_spi_read_rxfifo(spi, false); + + writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR); + + spin_unlock_irqrestore(&spi->lock, flags); + + if (end) { + stm32h7_spi_disable(spi); + spi_finalize_current_transfer(master); + } + + return IRQ_HANDLED; +} + +/** + * stm32_spi_prepare_msg - set up the controller to transfer a single message + * @master: controller master interface + * @msg: pointer to spi message + */ +static int stm32_spi_prepare_msg(struct spi_master *master, + struct spi_message *msg) +{ + struct stm32_spi *spi = spi_master_get_devdata(master); + struct spi_device *spi_dev = msg->spi; + struct device_node *np = spi_dev->dev.of_node; + unsigned long flags; + u32 clrb = 0, setb = 0; + + /* SPI slave device may need time between data frames */ + spi->cur_midi = 0; + if (np && !of_property_read_u32(np, "st,spi-midi-ns", &spi->cur_midi)) + dev_dbg(spi->dev, "%dns inter-data idleness\n", spi->cur_midi); + + if (spi_dev->mode & SPI_CPOL) + setb |= spi->cfg->regs->cpol.mask; + else + clrb |= spi->cfg->regs->cpol.mask; + + if (spi_dev->mode & SPI_CPHA) + setb |= spi->cfg->regs->cpha.mask; + else + clrb |= spi->cfg->regs->cpha.mask; + + if (spi_dev->mode & SPI_LSB_FIRST) + setb |= spi->cfg->regs->lsb_first.mask; + else + clrb |= spi->cfg->regs->lsb_first.mask; + + dev_dbg(spi->dev, "cpol=%d cpha=%d lsb_first=%d cs_high=%d\n", + spi_dev->mode & SPI_CPOL, + spi_dev->mode & SPI_CPHA, + spi_dev->mode & SPI_LSB_FIRST, + spi_dev->mode & SPI_CS_HIGH); + + spin_lock_irqsave(&spi->lock, flags); + + /* CPOL, CPHA and LSB FIRST bits have common register */ + if (clrb || setb) + writel_relaxed( + (readl_relaxed(spi->base + spi->cfg->regs->cpol.reg) & + ~clrb) | setb, + spi->base + spi->cfg->regs->cpol.reg); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 0; +} + +/** + * stm32f4_spi_dma_tx_cb - dma callback + * @data: pointer to the spi controller data structure + * + * DMA callback is called when the transfer is complete for DMA TX channel. + */ +static void stm32f4_spi_dma_tx_cb(void *data) +{ + struct stm32_spi *spi = data; + + if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { + spi_finalize_current_transfer(spi->master); + stm32f4_spi_disable(spi); + } +} + +/** + * stm32f4_spi_dma_rx_cb - dma callback + * @data: pointer to the spi controller data structure + * + * DMA callback is called when the transfer is complete for DMA RX channel. + */ +static void stm32f4_spi_dma_rx_cb(void *data) +{ + struct stm32_spi *spi = data; + + spi_finalize_current_transfer(spi->master); + stm32f4_spi_disable(spi); +} + +/** + * stm32h7_spi_dma_cb - dma callback + * @data: pointer to the spi controller data structure + * + * DMA callback is called when the transfer is complete or when an error + * occurs. If the transfer is complete, EOT flag is raised. + */ +static void stm32h7_spi_dma_cb(void *data) +{ + struct stm32_spi *spi = data; + unsigned long flags; + u32 sr; + + spin_lock_irqsave(&spi->lock, flags); + + sr = readl_relaxed(spi->base + STM32H7_SPI_SR); + + spin_unlock_irqrestore(&spi->lock, flags); + + if (!(sr & STM32H7_SPI_SR_EOT)) + dev_warn(spi->dev, "DMA error (sr=0x%08x)\n", sr); + + /* Now wait for EOT, or SUSP or OVR in case of error */ +} + +/** + * stm32_spi_dma_config - configure dma slave channel depending on current + * transfer bits_per_word. + * @spi: pointer to the spi controller data structure + * @dma_conf: pointer to the dma_slave_config structure + * @dir: direction of the dma transfer + */ +static void stm32_spi_dma_config(struct stm32_spi *spi, + struct dma_slave_config *dma_conf, + enum dma_transfer_direction dir) +{ + enum dma_slave_buswidth buswidth; + u32 maxburst; + + if (spi->cur_bpw <= 8) + buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; + else if (spi->cur_bpw <= 16) + buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; + else + buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; + + if (spi->cfg->has_fifo) { + /* Valid for DMA Half or Full Fifo threshold */ + if (spi->cur_fthlv == 2) + maxburst = 1; + else + maxburst = spi->cur_fthlv; + } else { + maxburst = 1; + } + + memset(dma_conf, 0, sizeof(struct dma_slave_config)); + dma_conf->direction = dir; + if (dma_conf->direction == DMA_DEV_TO_MEM) { /* RX */ + dma_conf->src_addr = spi->phys_addr + spi->cfg->regs->rx.reg; + dma_conf->src_addr_width = buswidth; + dma_conf->src_maxburst = maxburst; + + dev_dbg(spi->dev, "Rx DMA config buswidth=%d, maxburst=%d\n", + buswidth, maxburst); + } else if (dma_conf->direction == DMA_MEM_TO_DEV) { /* TX */ + dma_conf->dst_addr = spi->phys_addr + spi->cfg->regs->tx.reg; + dma_conf->dst_addr_width = buswidth; + dma_conf->dst_maxburst = maxburst; + + dev_dbg(spi->dev, "Tx DMA config buswidth=%d, maxburst=%d\n", + buswidth, maxburst); + } +} + +/** + * stm32f4_spi_transfer_one_irq - transfer a single spi_transfer using + * interrupts + * @spi: pointer to the spi controller data structure + * + * It must returns 0 if the transfer is finished or 1 if the transfer is still + * in progress. + */ +static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi) +{ + unsigned long flags; + u32 cr2 = 0; + + /* Enable the interrupts relative to the current communication mode */ + if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { + cr2 |= STM32F4_SPI_CR2_TXEIE; + } else if (spi->cur_comm == SPI_FULL_DUPLEX || + spi->cur_comm == SPI_SIMPLEX_RX || + spi->cur_comm == SPI_3WIRE_RX) { + /* In transmit-only mode, the OVR flag is set in the SR register + * since the received data are never read. Therefore set OVR + * interrupt only when rx buffer is available. + */ + cr2 |= STM32F4_SPI_CR2_RXNEIE | STM32F4_SPI_CR2_ERRIE; + } else { + return -EINVAL; + } + + spin_lock_irqsave(&spi->lock, flags); + + stm32_spi_set_bits(spi, STM32F4_SPI_CR2, cr2); + + stm32_spi_enable(spi); + + /* starting data transfer when buffer is loaded */ + if (spi->tx_buf) + stm32f4_spi_write_tx(spi); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 1; +} + +/** + * stm32h7_spi_transfer_one_irq - transfer a single spi_transfer using + * interrupts + * @spi: pointer to the spi controller data structure + * + * It must returns 0 if the transfer is finished or 1 if the transfer is still + * in progress. + */ +static int stm32h7_spi_transfer_one_irq(struct stm32_spi *spi) +{ + unsigned long flags; + u32 ier = 0; + + /* Enable the interrupts relative to the current communication mode */ + if (spi->tx_buf && spi->rx_buf) /* Full Duplex */ + ier |= STM32H7_SPI_IER_DXPIE; + else if (spi->tx_buf) /* Half-Duplex TX dir or Simplex TX */ + ier |= STM32H7_SPI_IER_TXPIE; + else if (spi->rx_buf) /* Half-Duplex RX dir or Simplex RX */ + ier |= STM32H7_SPI_IER_RXPIE; + + /* Enable the interrupts relative to the end of transfer */ + ier |= STM32H7_SPI_IER_EOTIE | STM32H7_SPI_IER_TXTFIE | + STM32H7_SPI_IER_OVRIE | STM32H7_SPI_IER_MODFIE; + + spin_lock_irqsave(&spi->lock, flags); + + stm32_spi_enable(spi); + + /* Be sure to have data in fifo before starting data transfer */ + if (spi->tx_buf) + stm32h7_spi_write_txfifo(spi); + + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART); + + writel_relaxed(ier, spi->base + STM32H7_SPI_IER); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 1; +} + +/** + * stm32f4_spi_transfer_one_dma_start - Set SPI driver registers to start + * transfer using DMA + * @spi: pointer to the spi controller data structure + */ +static void stm32f4_spi_transfer_one_dma_start(struct stm32_spi *spi) +{ + /* In DMA mode end of transfer is handled by DMA TX or RX callback. */ + if (spi->cur_comm == SPI_SIMPLEX_RX || spi->cur_comm == SPI_3WIRE_RX || + spi->cur_comm == SPI_FULL_DUPLEX) { + /* + * In transmit-only mode, the OVR flag is set in the SR register + * since the received data are never read. Therefore set OVR + * interrupt only when rx buffer is available. + */ + stm32_spi_set_bits(spi, STM32F4_SPI_CR2, STM32F4_SPI_CR2_ERRIE); + } + + stm32_spi_enable(spi); +} + +/** + * stm32h7_spi_transfer_one_dma_start - Set SPI driver registers to start + * transfer using DMA + * @spi: pointer to the spi controller data structure + */ +static void stm32h7_spi_transfer_one_dma_start(struct stm32_spi *spi) +{ + /* Enable the interrupts relative to the end of transfer */ + stm32_spi_set_bits(spi, STM32H7_SPI_IER, STM32H7_SPI_IER_EOTIE | + STM32H7_SPI_IER_TXTFIE | + STM32H7_SPI_IER_OVRIE | + STM32H7_SPI_IER_MODFIE); + + stm32_spi_enable(spi); + + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_CSTART); +} + +/** + * stm32_spi_transfer_one_dma - transfer a single spi_transfer using DMA + * @spi: pointer to the spi controller data structure + * @xfer: pointer to the spi_transfer structure + * + * It must returns 0 if the transfer is finished or 1 if the transfer is still + * in progress. + */ +static int stm32_spi_transfer_one_dma(struct stm32_spi *spi, + struct spi_transfer *xfer) +{ + struct dma_slave_config tx_dma_conf, rx_dma_conf; + struct dma_async_tx_descriptor *tx_dma_desc, *rx_dma_desc; + unsigned long flags; + + spin_lock_irqsave(&spi->lock, flags); + + rx_dma_desc = NULL; + if (spi->rx_buf && spi->dma_rx) { + stm32_spi_dma_config(spi, &rx_dma_conf, DMA_DEV_TO_MEM); + dmaengine_slave_config(spi->dma_rx, &rx_dma_conf); + + /* Enable Rx DMA request */ + stm32_spi_set_bits(spi, spi->cfg->regs->dma_rx_en.reg, + spi->cfg->regs->dma_rx_en.mask); + + rx_dma_desc = dmaengine_prep_slave_sg( + spi->dma_rx, xfer->rx_sg.sgl, + xfer->rx_sg.nents, + rx_dma_conf.direction, + DMA_PREP_INTERRUPT); + } + + tx_dma_desc = NULL; + if (spi->tx_buf && spi->dma_tx) { + stm32_spi_dma_config(spi, &tx_dma_conf, DMA_MEM_TO_DEV); + dmaengine_slave_config(spi->dma_tx, &tx_dma_conf); + + tx_dma_desc = dmaengine_prep_slave_sg( + spi->dma_tx, xfer->tx_sg.sgl, + xfer->tx_sg.nents, + tx_dma_conf.direction, + DMA_PREP_INTERRUPT); + } + + if ((spi->tx_buf && spi->dma_tx && !tx_dma_desc) || + (spi->rx_buf && spi->dma_rx && !rx_dma_desc)) + goto dma_desc_error; + + if (spi->cur_comm == SPI_FULL_DUPLEX && (!tx_dma_desc || !rx_dma_desc)) + goto dma_desc_error; + + if (rx_dma_desc) { + rx_dma_desc->callback = spi->cfg->dma_rx_cb; + rx_dma_desc->callback_param = spi; + + if (dma_submit_error(dmaengine_submit(rx_dma_desc))) { + dev_err(spi->dev, "Rx DMA submit failed\n"); + goto dma_desc_error; + } + /* Enable Rx DMA channel */ + dma_async_issue_pending(spi->dma_rx); + } + + if (tx_dma_desc) { + if (spi->cur_comm == SPI_SIMPLEX_TX || + spi->cur_comm == SPI_3WIRE_TX) { + tx_dma_desc->callback = spi->cfg->dma_tx_cb; + tx_dma_desc->callback_param = spi; + } + + if (dma_submit_error(dmaengine_submit(tx_dma_desc))) { + dev_err(spi->dev, "Tx DMA submit failed\n"); + goto dma_submit_error; + } + /* Enable Tx DMA channel */ + dma_async_issue_pending(spi->dma_tx); + + /* Enable Tx DMA request */ + stm32_spi_set_bits(spi, spi->cfg->regs->dma_tx_en.reg, + spi->cfg->regs->dma_tx_en.mask); + } + + spi->cfg->transfer_one_dma_start(spi); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 1; + +dma_submit_error: + if (spi->dma_rx) + dmaengine_terminate_all(spi->dma_rx); + +dma_desc_error: + stm32_spi_clr_bits(spi, spi->cfg->regs->dma_rx_en.reg, + spi->cfg->regs->dma_rx_en.mask); + + spin_unlock_irqrestore(&spi->lock, flags); + + dev_info(spi->dev, "DMA issue: fall back to irq transfer\n"); + + spi->cur_usedma = false; + return spi->cfg->transfer_one_irq(spi); +} + +/** + * stm32f4_spi_set_bpw - Configure bits per word + * @spi: pointer to the spi controller data structure + */ +static void stm32f4_spi_set_bpw(struct stm32_spi *spi) +{ + if (spi->cur_bpw == 16) + stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF); + else + stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_DFF); +} + +/** + * stm32h7_spi_set_bpw - configure bits per word + * @spi: pointer to the spi controller data structure + */ +static void stm32h7_spi_set_bpw(struct stm32_spi *spi) +{ + u32 bpw, fthlv; + u32 cfg1_clrb = 0, cfg1_setb = 0; + + bpw = spi->cur_bpw - 1; + + cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE; + cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) & + STM32H7_SPI_CFG1_DSIZE; + + spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen); + fthlv = spi->cur_fthlv - 1; + + cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV; + cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) & + STM32H7_SPI_CFG1_FTHLV; + + writel_relaxed( + (readl_relaxed(spi->base + STM32H7_SPI_CFG1) & + ~cfg1_clrb) | cfg1_setb, + spi->base + STM32H7_SPI_CFG1); +} + +/** + * stm32_spi_set_mbr - Configure baud rate divisor in master mode + * @spi: pointer to the spi controller data structure + * @mbrdiv: baud rate divisor value + */ +static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv) +{ + u32 clrb = 0, setb = 0; + + clrb |= spi->cfg->regs->br.mask; + setb |= ((u32)mbrdiv << spi->cfg->regs->br.shift) & + spi->cfg->regs->br.mask; + + writel_relaxed((readl_relaxed(spi->base + spi->cfg->regs->br.reg) & + ~clrb) | setb, + spi->base + spi->cfg->regs->br.reg); +} + +/** + * stm32_spi_communication_type - return transfer communication type + * @spi_dev: pointer to the spi device + * @transfer: pointer to spi transfer + */ +static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + unsigned int type = SPI_FULL_DUPLEX; + + if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */ + /* + * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL + * is forbidden and unvalidated by SPI subsystem so depending + * on the valid buffer, we can determine the direction of the + * transfer. + */ + if (!transfer->tx_buf) + type = SPI_3WIRE_RX; + else + type = SPI_3WIRE_TX; + } else { + if (!transfer->tx_buf) + type = SPI_SIMPLEX_RX; + else if (!transfer->rx_buf) + type = SPI_SIMPLEX_TX; + } + + return type; +} + +/** + * stm32f4_spi_set_mode - configure communication mode + * @spi: pointer to the spi controller data structure + * @comm_type: type of communication to configure + */ +static int stm32f4_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) +{ + if (comm_type == SPI_3WIRE_TX || comm_type == SPI_SIMPLEX_TX) { + stm32_spi_set_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIMODE | + STM32F4_SPI_CR1_BIDIOE); + } else if (comm_type == SPI_FULL_DUPLEX || + comm_type == SPI_SIMPLEX_RX) { + stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIMODE | + STM32F4_SPI_CR1_BIDIOE); + } else if (comm_type == SPI_3WIRE_RX) { + stm32_spi_set_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIMODE); + stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIOE); + } else { + return -EINVAL; + } + + return 0; +} + +/** + * stm32h7_spi_set_mode - configure communication mode + * @spi: pointer to the spi controller data structure + * @comm_type: type of communication to configure + */ +static int stm32h7_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) +{ + u32 mode; + u32 cfg2_clrb = 0, cfg2_setb = 0; + + if (comm_type == SPI_3WIRE_RX) { + mode = STM32H7_SPI_HALF_DUPLEX; + stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); + } else if (comm_type == SPI_3WIRE_TX) { + mode = STM32H7_SPI_HALF_DUPLEX; + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); + } else if (comm_type == SPI_SIMPLEX_RX) { + mode = STM32H7_SPI_SIMPLEX_RX; + } else if (comm_type == SPI_SIMPLEX_TX) { + mode = STM32H7_SPI_SIMPLEX_TX; + } else { + mode = STM32H7_SPI_FULL_DUPLEX; + } + + cfg2_clrb |= STM32H7_SPI_CFG2_COMM; + cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) & + STM32H7_SPI_CFG2_COMM; + + writel_relaxed( + (readl_relaxed(spi->base + STM32H7_SPI_CFG2) & + ~cfg2_clrb) | cfg2_setb, + spi->base + STM32H7_SPI_CFG2); + + return 0; +} + +/** + * stm32h7_spi_data_idleness - configure minimum time delay inserted between two + * consecutive data frames in master mode + * @spi: pointer to the spi controller data structure + * @len: transfer len + */ +static void stm32h7_spi_data_idleness(struct stm32_spi *spi, u32 len) +{ + u32 cfg2_clrb = 0, cfg2_setb = 0; + + cfg2_clrb |= STM32H7_SPI_CFG2_MIDI; + if ((len > 1) && (spi->cur_midi > 0)) { + u32 sck_period_ns = DIV_ROUND_UP(SPI_1HZ_NS, spi->cur_speed); + u32 midi = min((u32)DIV_ROUND_UP(spi->cur_midi, sck_period_ns), + (u32)STM32H7_SPI_CFG2_MIDI >> + STM32H7_SPI_CFG2_MIDI_SHIFT); + + dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n", + sck_period_ns, midi, midi * sck_period_ns); + cfg2_setb |= (midi << STM32H7_SPI_CFG2_MIDI_SHIFT) & + STM32H7_SPI_CFG2_MIDI; + } + + writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) & + ~cfg2_clrb) | cfg2_setb, + spi->base + STM32H7_SPI_CFG2); +} + +/** + * stm32h7_spi_number_of_data - configure number of data at current transfer + * @spi: pointer to the spi controller data structure + * @nb_words: transfer length (in words) + */ +static int stm32h7_spi_number_of_data(struct stm32_spi *spi, u32 nb_words) +{ + u32 cr2_clrb = 0, cr2_setb = 0; + + if (nb_words <= (STM32H7_SPI_CR2_TSIZE >> + STM32H7_SPI_CR2_TSIZE_SHIFT)) { + cr2_clrb |= STM32H7_SPI_CR2_TSIZE; + cr2_setb = nb_words << STM32H7_SPI_CR2_TSIZE_SHIFT; + writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CR2) & + ~cr2_clrb) | cr2_setb, + spi->base + STM32H7_SPI_CR2); + } else { + return -EMSGSIZE; + } + + return 0; +} + +/** + * stm32_spi_transfer_one_setup - common setup to transfer a single + * spi_transfer either using DMA or + * interrupts. + * @spi: pointer to the spi controller data structure + * @spi_dev: pointer to the spi device + * @transfer: pointer to spi transfer + */ +static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, + struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + unsigned long flags; + unsigned int comm_type; + int nb_words, ret = 0; + int mbr; + + spin_lock_irqsave(&spi->lock, flags); + + spi->cur_xferlen = transfer->len; + + spi->cur_bpw = transfer->bits_per_word; + spi->cfg->set_bpw(spi); + + /* Update spi->cur_speed with real clock speed */ + mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz, + spi->cfg->baud_rate_div_min, + spi->cfg->baud_rate_div_max); + if (mbr < 0) { + ret = mbr; + goto out; + } + + transfer->speed_hz = spi->cur_speed; + stm32_spi_set_mbr(spi, mbr); + + comm_type = stm32_spi_communication_type(spi_dev, transfer); + ret = spi->cfg->set_mode(spi, comm_type); + if (ret < 0) + goto out; + + spi->cur_comm = comm_type; + + if (spi->cfg->set_data_idleness) + spi->cfg->set_data_idleness(spi, transfer->len); + + if (spi->cur_bpw <= 8) + nb_words = transfer->len; + else if (spi->cur_bpw <= 16) + nb_words = DIV_ROUND_UP(transfer->len * 8, 16); + else + nb_words = DIV_ROUND_UP(transfer->len * 8, 32); + + if (spi->cfg->set_number_of_data) { + ret = spi->cfg->set_number_of_data(spi, nb_words); + if (ret < 0) + goto out; + } + + dev_dbg(spi->dev, "transfer communication mode set to %d\n", + spi->cur_comm); + dev_dbg(spi->dev, + "data frame of %d-bit, data packet of %d data frames\n", + spi->cur_bpw, spi->cur_fthlv); + dev_dbg(spi->dev, "speed set to %dHz\n", spi->cur_speed); + dev_dbg(spi->dev, "transfer of %d bytes (%d data frames)\n", + spi->cur_xferlen, nb_words); + dev_dbg(spi->dev, "dma %s\n", + (spi->cur_usedma) ? "enabled" : "disabled"); + +out: + spin_unlock_irqrestore(&spi->lock, flags); + + return ret; +} + +/** + * stm32_spi_transfer_one - transfer a single spi_transfer + * @master: controller master interface + * @spi_dev: pointer to the spi device + * @transfer: pointer to spi transfer + * + * It must return 0 if the transfer is finished or 1 if the transfer is still + * in progress. + */ +static int stm32_spi_transfer_one(struct spi_master *master, + struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + struct stm32_spi *spi = spi_master_get_devdata(master); + int ret; + + /* Don't do anything on 0 bytes transfers */ + if (transfer->len == 0) + return 0; + + spi->tx_buf = transfer->tx_buf; + spi->rx_buf = transfer->rx_buf; + spi->tx_len = spi->tx_buf ? transfer->len : 0; + spi->rx_len = spi->rx_buf ? transfer->len : 0; + + spi->cur_usedma = (master->can_dma && + master->can_dma(master, spi_dev, transfer)); + + ret = stm32_spi_transfer_one_setup(spi, spi_dev, transfer); + if (ret) { + dev_err(spi->dev, "SPI transfer setup failed\n"); + return ret; + } + + if (spi->cur_usedma) + return stm32_spi_transfer_one_dma(spi, transfer); + else + return spi->cfg->transfer_one_irq(spi); +} + +/** + * stm32_spi_unprepare_msg - relax the hardware + * @master: controller master interface + * @msg: pointer to the spi message + */ +static int stm32_spi_unprepare_msg(struct spi_master *master, + struct spi_message *msg) +{ + struct stm32_spi *spi = spi_master_get_devdata(master); + + spi->cfg->disable(spi); + + return 0; +} + +/** + * stm32f4_spi_config - Configure SPI controller as SPI master + * @spi: pointer to the spi controller data structure + */ +static int stm32f4_spi_config(struct stm32_spi *spi) +{ + unsigned long flags; + + spin_lock_irqsave(&spi->lock, flags); + + /* Ensure I2SMOD bit is kept cleared */ + stm32_spi_clr_bits(spi, STM32F4_SPI_I2SCFGR, + STM32F4_SPI_I2SCFGR_I2SMOD); + + /* + * - SS input value high + * - transmitter half duplex direction + * - Set the master mode (default Motorola mode) + * - Consider 1 master/n slaves configuration and + * SS input value is determined by the SSI bit + */ + stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_SSI | + STM32F4_SPI_CR1_BIDIOE | + STM32F4_SPI_CR1_MSTR | + STM32F4_SPI_CR1_SSM); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 0; +} + +/** + * stm32h7_spi_config - Configure SPI controller as SPI master + * @spi: pointer to the spi controller data structure + */ +static int stm32h7_spi_config(struct stm32_spi *spi) +{ + unsigned long flags; + + spin_lock_irqsave(&spi->lock, flags); + + /* Ensure I2SMOD bit is kept cleared */ + stm32_spi_clr_bits(spi, STM32H7_SPI_I2SCFGR, + STM32H7_SPI_I2SCFGR_I2SMOD); + + /* + * - SS input value high + * - transmitter half duplex direction + * - automatic communication suspend when RX-Fifo is full + */ + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_SSI | + STM32H7_SPI_CR1_HDDIR | + STM32H7_SPI_CR1_MASRX); + + /* + * - Set the master mode (default Motorola mode) + * - Consider 1 master/n slaves configuration and + * SS input value is determined by the SSI bit + * - keep control of all associated GPIOs + */ + stm32_spi_set_bits(spi, STM32H7_SPI_CFG2, STM32H7_SPI_CFG2_MASTER | + STM32H7_SPI_CFG2_SSM | + STM32H7_SPI_CFG2_AFCNTR); + + spin_unlock_irqrestore(&spi->lock, flags); + + return 0; +} + +static const struct stm32_spi_cfg stm32f4_spi_cfg = { + .regs = &stm32f4_spi_regspec, + .get_bpw_mask = stm32f4_spi_get_bpw_mask, + .disable = stm32f4_spi_disable, + .config = stm32f4_spi_config, + .set_bpw = stm32f4_spi_set_bpw, + .set_mode = stm32f4_spi_set_mode, + .transfer_one_dma_start = stm32f4_spi_transfer_one_dma_start, + .dma_tx_cb = stm32f4_spi_dma_tx_cb, + .dma_rx_cb = stm32f4_spi_dma_rx_cb, + .transfer_one_irq = stm32f4_spi_transfer_one_irq, + .irq_handler_event = stm32f4_spi_irq_event, + .irq_handler_thread = stm32f4_spi_irq_thread, + .baud_rate_div_min = STM32F4_SPI_BR_DIV_MIN, + .baud_rate_div_max = STM32F4_SPI_BR_DIV_MAX, + .has_fifo = false, +}; + +static const struct stm32_spi_cfg stm32h7_spi_cfg = { + .regs = &stm32h7_spi_regspec, + .get_fifo_size = stm32h7_spi_get_fifo_size, + .get_bpw_mask = stm32h7_spi_get_bpw_mask, + .disable = stm32h7_spi_disable, + .config = stm32h7_spi_config, + .set_bpw = stm32h7_spi_set_bpw, + .set_mode = stm32h7_spi_set_mode, + .set_data_idleness = stm32h7_spi_data_idleness, + .set_number_of_data = stm32h7_spi_number_of_data, + .transfer_one_dma_start = stm32h7_spi_transfer_one_dma_start, + .dma_rx_cb = stm32h7_spi_dma_cb, + .dma_tx_cb = stm32h7_spi_dma_cb, + .transfer_one_irq = stm32h7_spi_transfer_one_irq, + .irq_handler_thread = stm32h7_spi_irq_thread, + .baud_rate_div_min = STM32H7_SPI_MBR_DIV_MIN, + .baud_rate_div_max = STM32H7_SPI_MBR_DIV_MAX, + .has_fifo = true, +}; + +static const struct of_device_id stm32_spi_of_match[] = { + { .compatible = "st,stm32h7-spi", .data = (void *)&stm32h7_spi_cfg }, + { .compatible = "st,stm32f4-spi", .data = (void *)&stm32f4_spi_cfg }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_spi_of_match); + +static int stm32_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct stm32_spi *spi; + struct resource *res; + int ret; + + master = devm_spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi)); + if (!master) { + dev_err(&pdev->dev, "spi master allocation failed\n"); + return -ENOMEM; + } + platform_set_drvdata(pdev, master); + + spi = spi_master_get_devdata(master); + spi->dev = &pdev->dev; + spi->master = master; + spin_lock_init(&spi->lock); + + spi->cfg = (const struct stm32_spi_cfg *) + of_match_device(pdev->dev.driver->of_match_table, + &pdev->dev)->data; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + spi->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(spi->base)) + return PTR_ERR(spi->base); + + spi->phys_addr = (dma_addr_t)res->start; + + spi->irq = platform_get_irq(pdev, 0); + if (spi->irq <= 0) + return dev_err_probe(&pdev->dev, spi->irq, + "failed to get irq\n"); + + ret = devm_request_threaded_irq(&pdev->dev, spi->irq, + spi->cfg->irq_handler_event, + spi->cfg->irq_handler_thread, + IRQF_ONESHOT, pdev->name, master); + if (ret) { + dev_err(&pdev->dev, "irq%d request failed: %d\n", spi->irq, + ret); + return ret; + } + + spi->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(spi->clk)) { + ret = PTR_ERR(spi->clk); + dev_err(&pdev->dev, "clk get failed: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(spi->clk); + if (ret) { + dev_err(&pdev->dev, "clk enable failed: %d\n", ret); + return ret; + } + spi->clk_rate = clk_get_rate(spi->clk); + if (!spi->clk_rate) { + dev_err(&pdev->dev, "clk rate = 0\n"); + ret = -EINVAL; + goto err_clk_disable; + } + + spi->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (!IS_ERR(spi->rst)) { + reset_control_assert(spi->rst); + udelay(2); + reset_control_deassert(spi->rst); + } + + if (spi->cfg->has_fifo) + spi->fifo_size = spi->cfg->get_fifo_size(spi); + + ret = spi->cfg->config(spi); + if (ret) { + dev_err(&pdev->dev, "controller configuration failed: %d\n", + ret); + goto err_clk_disable; + } + + master->dev.of_node = pdev->dev.of_node; + master->auto_runtime_pm = true; + master->bus_num = pdev->id; + master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST | + SPI_3WIRE; + master->bits_per_word_mask = spi->cfg->get_bpw_mask(spi); + master->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min; + master->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max; + master->use_gpio_descriptors = true; + master->prepare_message = stm32_spi_prepare_msg; + master->transfer_one = stm32_spi_transfer_one; + master->unprepare_message = stm32_spi_unprepare_msg; + master->flags = SPI_MASTER_MUST_TX; + + spi->dma_tx = dma_request_chan(spi->dev, "tx"); + if (IS_ERR(spi->dma_tx)) { + ret = PTR_ERR(spi->dma_tx); + spi->dma_tx = NULL; + if (ret == -EPROBE_DEFER) + goto err_clk_disable; + + dev_warn(&pdev->dev, "failed to request tx dma channel\n"); + } else { + master->dma_tx = spi->dma_tx; + } + + spi->dma_rx = dma_request_chan(spi->dev, "rx"); + if (IS_ERR(spi->dma_rx)) { + ret = PTR_ERR(spi->dma_rx); + spi->dma_rx = NULL; + if (ret == -EPROBE_DEFER) + goto err_dma_release; + + dev_warn(&pdev->dev, "failed to request rx dma channel\n"); + } else { + master->dma_rx = spi->dma_rx; + } + + if (spi->dma_tx || spi->dma_rx) + master->can_dma = stm32_spi_can_dma; + + pm_runtime_set_active(&pdev->dev); + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + ret = spi_register_master(master); + if (ret) { + dev_err(&pdev->dev, "spi master registration failed: %d\n", + ret); + goto err_pm_disable; + } + + if (!master->cs_gpiods) { + dev_err(&pdev->dev, "no CS gpios available\n"); + ret = -EINVAL; + goto err_pm_disable; + } + + dev_info(&pdev->dev, "driver initialized\n"); + + return 0; + +err_pm_disable: + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); +err_dma_release: + if (spi->dma_tx) + dma_release_channel(spi->dma_tx); + if (spi->dma_rx) + dma_release_channel(spi->dma_rx); +err_clk_disable: + clk_disable_unprepare(spi->clk); + + return ret; +} + +static int stm32_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct stm32_spi *spi = spi_master_get_devdata(master); + + pm_runtime_get_sync(&pdev->dev); + + spi_unregister_master(master); + spi->cfg->disable(spi); + + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + if (master->dma_tx) + dma_release_channel(master->dma_tx); + if (master->dma_rx) + dma_release_channel(master->dma_rx); + + clk_disable_unprepare(spi->clk); + + + pinctrl_pm_select_sleep_state(&pdev->dev); + + return 0; +} + +#ifdef CONFIG_PM +static int stm32_spi_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct stm32_spi *spi = spi_master_get_devdata(master); + + clk_disable_unprepare(spi->clk); + + return pinctrl_pm_select_sleep_state(dev); +} + +static int stm32_spi_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct stm32_spi *spi = spi_master_get_devdata(master); + int ret; + + ret = pinctrl_pm_select_default_state(dev); + if (ret) + return ret; + + return clk_prepare_enable(spi->clk); +} +#endif + +#ifdef CONFIG_PM_SLEEP +static int stm32_spi_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + int ret; + + ret = spi_master_suspend(master); + if (ret) + return ret; + + return pm_runtime_force_suspend(dev); +} + +static int stm32_spi_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct stm32_spi *spi = spi_master_get_devdata(master); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + return ret; + + ret = spi_master_resume(master); + if (ret) { + clk_disable_unprepare(spi->clk); + return ret; + } + + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + pm_runtime_put_noidle(dev); + dev_err(dev, "Unable to power device:%d\n", ret); + return ret; + } + + spi->cfg->config(spi); + + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return 0; +} +#endif + +static const struct dev_pm_ops stm32_spi_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(stm32_spi_suspend, stm32_spi_resume) + SET_RUNTIME_PM_OPS(stm32_spi_runtime_suspend, + stm32_spi_runtime_resume, NULL) +}; + +static struct platform_driver stm32_spi_driver = { + .probe = stm32_spi_probe, + .remove = stm32_spi_remove, + .driver = { + .name = DRIVER_NAME, + .pm = &stm32_spi_pm_ops, + .of_match_table = stm32_spi_of_match, + }, +}; + +module_platform_driver(stm32_spi_driver); + +MODULE_ALIAS("platform:" DRIVER_NAME); +MODULE_DESCRIPTION("STMicroelectronics STM32 SPI Controller driver"); +MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>"); +MODULE_LICENSE("GPL v2"); |