[PATCH] spi: add STM32 SPI controller driver
Ahmad Fatoum
a.fatoum at pengutronix.de
Fri Nov 5 00:46:57 PDT 2021
Tested on a STM32MP1 communicating with a ksz9563.
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
arch/arm/configs/stm32mp_defconfig | 7 +-
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/stm32_spi.c | 590 +++++++++++++++++++++++++++++
4 files changed, 604 insertions(+), 1 deletion(-)
create mode 100644 drivers/spi/stm32_spi.c
diff --git a/arch/arm/configs/stm32mp_defconfig b/arch/arm/configs/stm32mp_defconfig
index 49041b1f48f3..eb3c95b12c48 100644
--- a/arch/arm/configs/stm32mp_defconfig
+++ b/arch/arm/configs/stm32mp_defconfig
@@ -82,6 +82,7 @@ CONFIG_CMD_FLASH=y
CONFIG_CMD_GPIO=y
CONFIG_CMD_LED=y
CONFIG_CMD_POWEROFF=y
+CONFIG_CMD_SPI=y
CONFIG_CMD_WD=y
CONFIG_CMD_BAREBOX_UPDATE=y
CONFIG_CMD_OF_DIFF=y
@@ -102,9 +103,12 @@ CONFIG_DRIVER_NET_DESIGNWARE_STM32=y
CONFIG_AT803X_PHY=y
CONFIG_MICREL_PHY=y
CONFIG_REALTEK_PHY=y
-# CONFIG_SPI is not set
+CONFIG_DRIVER_SPI_STM32=y
CONFIG_I2C=y
CONFIG_I2C_STM32=y
+CONFIG_MTD=y
+CONFIG_MTD_M25P80=y
+CONFIG_MTD_SST25L=y
CONFIG_USB_HOST=y
CONFIG_USB_DWC2_HOST=y
CONFIG_USB_DWC2_GADGET=y
@@ -126,6 +130,7 @@ CONFIG_LED_GPIO=y
CONFIG_LED_PWM=y
CONFIG_LED_GPIO_OF=y
CONFIG_LED_TRIGGERS=y
+CONFIG_EEPROM_AT25=y
CONFIG_EEPROM_AT24=y
CONFIG_KEYBOARD_GPIO=y
CONFIG_INPUT_SPECIALKEYS=y
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 323d93efeb1a..d16cec3164fd 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -103,6 +103,13 @@ config SPI_ZYNQ_QSPI
This enables support for the Zynq Quad SPI controller in master mode.
This controller only supports SPI memory interface.
+config DRIVER_SPI_STM32
+ bool "STM32 SPI driver"
+ depends on ARCH_STM32MP || COMPILE_TEST
+ help
+ Enable the STM32 Serial Peripheral Interface (SPI) driver for STM32MP
+ SoCs.
+
endif
endmenu
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 908d514a01eb..23c1dd19f983 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_SPI_ATMEL_QUADSPI) += atmel-quadspi.o
obj-$(CONFIG_DRIVER_SPI_OMAP3) += omap3_spi.o
obj-$(CONFIG_DRIVER_SPI_DSPI) += dspi_spi.o
obj-$(CONFIG_SPI_ZYNQ_QSPI) += zynq_qspi.o
+obj-$(CONFIG_DRIVER_SPI_STM32) += stm32_spi.o
diff --git a/drivers/spi/stm32_spi.c b/drivers/spi/stm32_spi.c
new file mode 100644
index 000000000000..0cb04a968c8a
--- /dev/null
+++ b/drivers/spi/stm32_spi.c
@@ -0,0 +1,590 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ *
+ * Driver for STMicroelectronics Serial peripheral interface (SPI)
+ */
+
+#include <common.h>
+#include <linux/clk.h>
+#include <driver.h>
+#include <init.h>
+#include <errno.h>
+#include <linux/reset.h>
+#include <spi/spi.h>
+#include <linux/bitops.h>
+#include <clock.h>
+#include <gpio.h>
+#include <of_gpio.h>
+#include <linux/bitfield.h>
+#include <linux/iopoll.h>
+
+/* STM32 SPI registers */
+#define STM32_SPI_CR1 0x00
+#define STM32_SPI_CR2 0x04
+#define STM32_SPI_CFG1 0x08
+#define STM32_SPI_CFG2 0x0C
+#define STM32_SPI_SR 0x14
+#define STM32_SPI_IFCR 0x18
+#define STM32_SPI_TXDR 0x20
+#define STM32_SPI_RXDR 0x30
+#define STM32_SPI_I2SCFGR 0x50
+
+/* STM32_SPI_CR1 bit fields */
+#define SPI_CR1_SPE BIT(0)
+#define SPI_CR1_MASRX BIT(8)
+#define SPI_CR1_CSTART BIT(9)
+#define SPI_CR1_CSUSP BIT(10)
+#define SPI_CR1_HDDIR BIT(11)
+#define SPI_CR1_SSI BIT(12)
+
+/* STM32_SPI_CR2 bit fields */
+#define SPI_CR2_TSIZE GENMASK(15, 0)
+
+/* STM32_SPI_CFG1 bit fields */
+#define SPI_CFG1_DSIZE GENMASK(4, 0)
+#define SPI_CFG1_DSIZE_MIN 3
+#define SPI_CFG1_FTHLV_SHIFT 5
+#define SPI_CFG1_FTHLV GENMASK(8, 5)
+#define SPI_CFG1_MBR_SHIFT 28
+#define SPI_CFG1_MBR GENMASK(30, 28)
+#define SPI_CFG1_MBR_MIN 0
+#define SPI_CFG1_MBR_MAX FIELD_GET(SPI_CFG1_MBR, SPI_CFG1_MBR)
+
+/* STM32_SPI_CFG2 bit fields */
+#define SPI_CFG2_COMM_SHIFT 17
+#define SPI_CFG2_COMM GENMASK(18, 17)
+#define SPI_CFG2_MASTER BIT(22)
+#define SPI_CFG2_LSBFRST BIT(23)
+#define SPI_CFG2_CPHA BIT(24)
+#define SPI_CFG2_CPOL BIT(25)
+#define SPI_CFG2_SSM BIT(26)
+#define SPI_CFG2_AFCNTR BIT(31)
+
+/* STM32_SPI_SR bit fields */
+#define SPI_SR_RXP BIT(0)
+#define SPI_SR_TXP BIT(1)
+#define SPI_SR_EOT BIT(3)
+#define SPI_SR_TXTF BIT(4)
+#define SPI_SR_OVR BIT(6)
+#define SPI_SR_SUSP BIT(11)
+#define SPI_SR_RXPLVL_SHIFT 13
+#define SPI_SR_RXPLVL GENMASK(14, 13)
+#define SPI_SR_RXWNE BIT(15)
+
+/* STM32_SPI_IFCR bit fields */
+#define SPI_IFCR_ALL GENMASK(11, 3)
+
+/* STM32_SPI_I2SCFGR bit fields */
+#define SPI_I2SCFGR_I2SMOD BIT(0)
+
+/* SPI Master Baud Rate min/max divisor */
+#define STM32_MBR_DIV_MIN (2 << SPI_CFG1_MBR_MIN)
+#define STM32_MBR_DIV_MAX (2 << SPI_CFG1_MBR_MAX)
+
+/* SPI Communication mode */
+#define SPI_FULL_DUPLEX 0
+#define SPI_SIMPLEX_TX 1
+#define SPI_SIMPLEX_RX 2
+#define SPI_HALF_DUPLEX 3
+
+struct stm32_spi_priv {
+ struct spi_master master;
+ int *cs_gpios;
+ void __iomem *base;
+ struct clk *clk;
+ ulong bus_clk_rate;
+ unsigned int fifo_size;
+ unsigned int cur_bpw;
+ unsigned int cur_hz;
+ unsigned int cur_xferlen; /* current transfer length in bytes */
+ unsigned int tx_len; /* number of data to be written in bytes */
+ unsigned int rx_len; /* number of data to be read in bytes */
+ const void *tx_buf; /* data to be written, or NULL */
+ void *rx_buf; /* data to be read, or NULL */
+ u32 cur_mode;
+};
+
+static inline struct stm32_spi_priv *to_stm32_spi_priv(struct spi_master *master)
+{
+ return container_of(master, struct stm32_spi_priv, master);
+}
+
+static void stm32_spi_write_txfifo(struct stm32_spi_priv *priv)
+{
+ while ((priv->tx_len > 0) &&
+ (readl(priv->base + STM32_SPI_SR) & SPI_SR_TXP)) {
+ u32 offs = priv->cur_xferlen - priv->tx_len;
+
+ if (priv->tx_len >= sizeof(u32) &&
+ IS_ALIGNED((uintptr_t)(priv->tx_buf + offs), sizeof(u32))) {
+ const u32 *tx_buf32 = (const u32 *)(priv->tx_buf + offs);
+
+ writel(*tx_buf32, priv->base + STM32_SPI_TXDR);
+ priv->tx_len -= sizeof(u32);
+ } else if (priv->tx_len >= sizeof(u16) &&
+ IS_ALIGNED((uintptr_t)(priv->tx_buf + offs), sizeof(u16))) {
+ const u16 *tx_buf16 = (const u16 *)(priv->tx_buf + offs);
+
+ writew(*tx_buf16, priv->base + STM32_SPI_TXDR);
+ priv->tx_len -= sizeof(u16);
+ } else {
+ const u8 *tx_buf8 = (const u8 *)(priv->tx_buf + offs);
+
+ writeb(*tx_buf8, priv->base + STM32_SPI_TXDR);
+ priv->tx_len -= sizeof(u8);
+ }
+ }
+
+ dev_dbg(priv->master.dev, "%d bytes left\n", priv->tx_len);
+}
+
+static void stm32_spi_read_rxfifo(struct stm32_spi_priv *priv)
+{
+ u32 sr = readl(priv->base + STM32_SPI_SR);
+ u32 rxplvl = (sr & SPI_SR_RXPLVL) >> SPI_SR_RXPLVL_SHIFT;
+
+ while ((priv->rx_len > 0) &&
+ ((sr & SPI_SR_RXP) ||
+ ((sr & SPI_SR_EOT) && ((sr & SPI_SR_RXWNE) || (rxplvl > 0))))) {
+ u32 offs = priv->cur_xferlen - priv->rx_len;
+
+ if (IS_ALIGNED((uintptr_t)(priv->rx_buf + offs), sizeof(u32)) &&
+ (priv->rx_len >= sizeof(u32) || (sr & SPI_SR_RXWNE))) {
+ u32 *rx_buf32 = (u32 *)(priv->rx_buf + offs);
+
+ *rx_buf32 = readl(priv->base + STM32_SPI_RXDR);
+ priv->rx_len -= sizeof(u32);
+ } else if (IS_ALIGNED((uintptr_t)(priv->rx_buf + offs), sizeof(u16)) &&
+ (priv->rx_len >= sizeof(u16) ||
+ (!(sr & SPI_SR_RXWNE) &&
+ (rxplvl >= 2 || priv->cur_bpw > 8)))) {
+ u16 *rx_buf16 = (u16 *)(priv->rx_buf + offs);
+
+ *rx_buf16 = readw(priv->base + STM32_SPI_RXDR);
+ priv->rx_len -= sizeof(u16);
+ } else {
+ u8 *rx_buf8 = (u8 *)(priv->rx_buf + offs);
+
+ *rx_buf8 = readb(priv->base + STM32_SPI_RXDR);
+ priv->rx_len -= sizeof(u8);
+ }
+
+ sr = readl(priv->base + STM32_SPI_SR);
+ rxplvl = (sr & SPI_SR_RXPLVL) >> SPI_SR_RXPLVL_SHIFT;
+ }
+
+ dev_dbg(priv->master.dev, "%d bytes left\n", priv->rx_len);
+}
+
+static void stm32_spi_enable(struct stm32_spi_priv *priv)
+{
+ setbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
+}
+
+static void stm32_spi_disable(struct stm32_spi_priv *priv)
+{
+ clrbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
+}
+
+static void stm32_spi_stopxfer(struct stm32_spi_priv *priv)
+{
+ struct device_d *dev = priv->master.dev;
+ u32 cr1, sr;
+ int ret;
+
+ dev_dbg(dev, "%s\n", __func__);
+
+ cr1 = readl(priv->base + STM32_SPI_CR1);
+
+ if (!(cr1 & SPI_CR1_SPE))
+ return;
+
+ /* Wait on EOT or suspend the flow */
+ ret = readl_poll_timeout(priv->base + STM32_SPI_SR, sr,
+ !(sr & SPI_SR_EOT), USEC_PER_SEC);
+ if (ret < 0) {
+ if (cr1 & SPI_CR1_CSTART) {
+ writel(cr1 | SPI_CR1_CSUSP, priv->base + STM32_SPI_CR1);
+ if (readl_poll_timeout(priv->base + STM32_SPI_SR,
+ sr, !(sr & SPI_SR_SUSP),
+ 100000) < 0)
+ dev_err(dev, "Suspend request timeout\n");
+ }
+ }
+
+ /* clear status flags */
+ setbits_le32(priv->base + STM32_SPI_IFCR, SPI_IFCR_ALL);
+}
+
+static void stm32_spi_set_cs(struct spi_device *spi, bool en)
+{
+ struct stm32_spi_priv *priv = to_stm32_spi_priv(spi->master);
+ int gpio = priv->cs_gpios[spi->chip_select];
+ int ret = -EINVAL;
+
+ dev_dbg(priv->master.dev, "cs=%d en=%d\n", gpio, en);
+
+ if (gpio_is_valid(gpio))
+ ret = gpio_direction_output(gpio, (spi->mode & SPI_CS_HIGH) ? en : !en);
+
+ if (ret)
+ dev_warn(priv->master.dev, "couldn't toggle cs#%u\n", spi->chip_select);
+}
+
+static void stm32_spi_set_mode(struct stm32_spi_priv *priv, unsigned mode)
+{
+ u32 cfg2_clrb = 0, cfg2_setb = 0;
+
+ dev_dbg(priv->master.dev, "mode=%d\n", mode);
+
+ if (mode & SPI_CPOL)
+ cfg2_setb |= SPI_CFG2_CPOL;
+ else
+ cfg2_clrb |= SPI_CFG2_CPOL;
+
+ if (mode & SPI_CPHA)
+ cfg2_setb |= SPI_CFG2_CPHA;
+ else
+ cfg2_clrb |= SPI_CFG2_CPHA;
+
+ if (mode & SPI_LSB_FIRST)
+ cfg2_setb |= SPI_CFG2_LSBFRST;
+ else
+ cfg2_clrb |= SPI_CFG2_LSBFRST;
+
+ if (cfg2_clrb || cfg2_setb)
+ clrsetbits_le32(priv->base + STM32_SPI_CFG2,
+ cfg2_clrb, cfg2_setb);
+}
+
+static void stm32_spi_set_fthlv(struct stm32_spi_priv *priv, u32 xfer_len)
+{
+ u32 fthlv, half_fifo;
+
+ /* data packet should not exceed 1/2 of fifo space */
+ half_fifo = (priv->fifo_size / 2);
+
+ /* data_packet should not exceed transfer length */
+ fthlv = (half_fifo > xfer_len) ? xfer_len : half_fifo;
+
+ /* align packet size with data registers access */
+ fthlv -= (fthlv % 4);
+
+ if (!fthlv)
+ fthlv = 1;
+ clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_FTHLV,
+ (fthlv - 1) << SPI_CFG1_FTHLV_SHIFT);
+}
+
+static int stm32_spi_set_speed(struct stm32_spi_priv *priv, uint hz)
+{
+ u32 mbrdiv;
+ long div;
+
+ dev_dbg(priv->master.dev, "hz=%d\n", hz);
+
+ if (priv->cur_hz == hz)
+ return 0;
+
+ div = DIV_ROUND_UP(priv->bus_clk_rate, hz);
+
+ if (div < STM32_MBR_DIV_MIN || div > STM32_MBR_DIV_MAX)
+ 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;
+
+ if (!mbrdiv)
+ return -EINVAL;
+
+ clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_MBR,
+ (mbrdiv - 1) << SPI_CFG1_MBR_SHIFT);
+
+ priv->cur_hz = hz;
+
+ return 0;
+}
+
+static int stm32_spi_setup(struct spi_device *spi)
+{
+ struct stm32_spi_priv *priv = to_stm32_spi_priv(spi->master);
+ int ret;
+
+ stm32_spi_set_cs(spi, false);
+ stm32_spi_enable(priv);
+
+ stm32_spi_set_mode(priv, spi->mode);
+
+ ret = stm32_spi_set_speed(priv, spi->max_speed_hz);
+ if (ret)
+ goto out;
+
+ priv->cur_bpw = spi->bits_per_word;
+ clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_DSIZE,
+ priv->cur_bpw - 1);
+
+ dev_dbg(priv->master.dev, "%s mode 0x%08x bits_per_word: %d speed: %d\n",
+ __func__, spi->mode, spi->bits_per_word,
+ spi->max_speed_hz);
+out:
+ stm32_spi_disable(priv);
+ return ret;
+}
+
+static int stm32_spi_transfer_one(struct stm32_spi_priv *priv,
+ struct spi_transfer *t)
+{
+ struct device_d *dev = priv->master.dev;
+ u32 sr;
+ u32 ifcr = 0;
+ u32 mode;
+ int xfer_status = 0;
+
+ if (t->len <= SPI_CR2_TSIZE)
+ writel(t->len, priv->base + STM32_SPI_CR2);
+ else
+ return -EMSGSIZE;
+
+ priv->tx_buf = t->tx_buf;
+ priv->rx_buf = t->rx_buf;
+ priv->tx_len = priv->tx_buf ? t->len : 0;
+ priv->rx_len = priv->rx_buf ? t->len : 0;
+
+ mode = SPI_FULL_DUPLEX;
+ if (!priv->tx_buf)
+ mode = SPI_SIMPLEX_RX;
+ else if (!priv->rx_buf)
+ mode = SPI_SIMPLEX_TX;
+
+ if (priv->cur_xferlen != t->len || priv->cur_mode != mode) {
+ priv->cur_mode = mode;
+ priv->cur_xferlen = t->len;
+
+ /* Disable the SPI hardware to unlock CFG1/CFG2 registers */
+ stm32_spi_disable(priv);
+
+ clrsetbits_le32(priv->base + STM32_SPI_CFG2, SPI_CFG2_COMM,
+ mode << SPI_CFG2_COMM_SHIFT);
+
+ stm32_spi_set_fthlv(priv, t->len);
+
+ /* Enable the SPI hardware */
+ stm32_spi_enable(priv);
+ }
+
+ dev_dbg(dev, "priv->tx_len=%d priv->rx_len=%d\n",
+ priv->tx_len, priv->rx_len);
+
+ /* Be sure to have data in fifo before starting data transfer */
+ if (priv->tx_buf)
+ stm32_spi_write_txfifo(priv);
+
+ setbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_CSTART);
+
+ while (1) {
+ sr = readl(priv->base + STM32_SPI_SR);
+
+ if (sr & SPI_SR_OVR) {
+ dev_err(dev, "Overrun: RX data lost\n");
+ xfer_status = -EIO;
+ break;
+ }
+
+ if (sr & SPI_SR_SUSP) {
+ dev_warn(dev, "System too slow is limiting data throughput\n");
+
+ if (priv->rx_buf && priv->rx_len > 0)
+ stm32_spi_read_rxfifo(priv);
+
+ ifcr |= SPI_SR_SUSP;
+ }
+
+ if (sr & SPI_SR_TXTF)
+ ifcr |= SPI_SR_TXTF;
+
+ if (sr & SPI_SR_TXP)
+ if (priv->tx_buf && priv->tx_len > 0)
+ stm32_spi_write_txfifo(priv);
+
+ if (sr & SPI_SR_RXP)
+ if (priv->rx_buf && priv->rx_len > 0)
+ stm32_spi_read_rxfifo(priv);
+
+ if (sr & SPI_SR_EOT) {
+ if (priv->rx_buf && priv->rx_len > 0)
+ stm32_spi_read_rxfifo(priv);
+ break;
+ }
+
+ writel(ifcr, priv->base + STM32_SPI_IFCR);
+ }
+
+ /* clear status flags */
+ setbits_le32(priv->base + STM32_SPI_IFCR, SPI_IFCR_ALL);
+ stm32_spi_stopxfer(priv);
+
+ return xfer_status;
+}
+
+static int stm32_spi_transfer(struct spi_device *spi, struct spi_message *mesg)
+{
+ struct stm32_spi_priv *priv = to_stm32_spi_priv(spi->master);
+ struct spi_transfer *t;
+ unsigned int cs_change;
+ const int nsecs = 50;
+ int ret = 0;
+
+ stm32_spi_enable(priv);
+
+ stm32_spi_set_cs(spi, true);
+
+ cs_change = 0;
+
+ mesg->actual_length = 0;
+
+ list_for_each_entry(t, &mesg->transfers, transfer_list) {
+ if (cs_change) {
+ ndelay(nsecs);
+ stm32_spi_set_cs(spi, false);
+ ndelay(nsecs);
+ stm32_spi_set_cs(spi, true);
+ }
+
+ cs_change = t->cs_change;
+
+ ret = stm32_spi_transfer_one(priv, t);
+ if (ret)
+ goto out;
+
+ mesg->actual_length += t->len;
+
+ if (cs_change)
+ stm32_spi_set_cs(spi, true);
+ }
+
+ if (!cs_change)
+ stm32_spi_set_cs(spi, false);
+
+out:
+ stm32_spi_disable(priv);
+ return ret;
+}
+
+static int stm32_spi_get_fifo_size(struct stm32_spi_priv *priv)
+{
+ u32 count = 0;
+
+ stm32_spi_enable(priv);
+
+ while (readl(priv->base + STM32_SPI_SR) & SPI_SR_TXP)
+ writeb(++count, priv->base + STM32_SPI_TXDR);
+
+ stm32_spi_disable(priv);
+
+ dev_dbg(priv->master.dev, "%d x 8-bit fifo size\n", count);
+
+ return count;
+}
+
+static void stm32_spi_dt_probe(struct stm32_spi_priv *priv)
+{
+ struct device_node *node = priv->master.dev->device_node;
+ int i;
+
+ priv->master.num_chipselect = of_gpio_named_count(node, "cs-gpios");
+ priv->cs_gpios = xzalloc(sizeof(u32) * priv->master.num_chipselect);
+
+ for (i = 0; i < priv->master.num_chipselect; i++)
+ priv->cs_gpios[i] = of_get_named_gpio(node, "cs-gpios", i);
+}
+
+static int stm32_spi_probe(struct device_d *dev)
+{
+ struct resource *iores;
+ struct spi_master *master;
+ struct stm32_spi_priv *priv;
+ int ret;
+
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores))
+ return PTR_ERR(iores);
+
+ priv = dev->priv = xzalloc(sizeof(*priv));
+
+ priv->base = IOMEM(iores->start);
+
+ master = &priv->master;
+ master->dev = dev;
+
+ master->setup = stm32_spi_setup;
+ master->transfer = stm32_spi_transfer;
+
+ master->bus_num = -1;
+ stm32_spi_dt_probe(priv);
+
+ priv->clk = clk_get(dev, NULL);
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
+ ret = clk_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ priv->bus_clk_rate = clk_get_rate(priv->clk);
+
+ ret = device_reset_us(dev, 2);
+ if (ret)
+ return ret;
+
+ priv->fifo_size = stm32_spi_get_fifo_size(priv);
+
+ priv->cur_mode = SPI_FULL_DUPLEX;
+ priv->cur_xferlen = 0;
+
+ /* Ensure I2SMOD bit is kept cleared */
+ clrbits_le32(priv->base + STM32_SPI_I2SCFGR, SPI_I2SCFGR_I2SMOD);
+
+ /*
+ * - SS input value high
+ * - transmitter half duplex direction
+ * - automatic communication suspend when RX-Fifo is full
+ */
+ setbits_le32(priv->base + STM32_SPI_CR1,
+ SPI_CR1_SSI | SPI_CR1_HDDIR | 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
+ */
+ setbits_le32(priv->base + STM32_SPI_CFG2,
+ SPI_CFG2_MASTER | SPI_CFG2_SSM | SPI_CFG2_AFCNTR);
+
+ return spi_register_master(master);
+}
+
+static void stm32_spi_remove(struct device_d *dev)
+{
+ struct stm32_spi_priv *priv = dev->priv;
+
+ stm32_spi_stopxfer(priv);
+ stm32_spi_disable(priv);
+};
+
+static const struct of_device_id stm32_spi_ids[] = {
+ { .compatible = "st,stm32h7-spi", },
+ { /* sentinel */ }
+};
+
+static struct driver_d stm32_spi_driver = {
+ .name = "stm32_spi",
+ .probe = stm32_spi_probe,
+ .remove = stm32_spi_remove,
+ .of_compatible = stm32_spi_ids,
+};
+coredevice_platform_driver(stm32_spi_driver);
--
2.30.2
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