--- /dev/null
+// 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 <clk.h>
+#include <dm.h>
+#include <errno.h>
+#include <reset.h>
+#include <spi.h>
+
+#include <asm/io.h>
+#include <asm/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)
+
+#define MAX_CS_COUNT 4
+
+/* 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)
+
+#define STM32_SPI_TIMEOUT_US 100000
+
+/* 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 {
+ void __iomem *base;
+ struct clk clk;
+ struct reset_ctl rst_ctl;
+ struct gpio_desc cs_gpios[MAX_CS_COUNT];
+ 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 */
+ int tx_len; /* number of data to be written in bytes */
+ 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;
+ bool cs_high;
+};
+
+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);
+ }
+ }
+
+ debug("%s: %d bytes left\n", __func__, 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;
+ }
+
+ debug("%s: %d bytes left\n", __func__, priv->rx_len);
+}
+
+static int stm32_spi_enable(struct stm32_spi_priv *priv)
+{
+ debug("%s\n", __func__);
+
+ /* Enable the SPI hardware */
+ setbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
+
+ return 0;
+}
+
+static int stm32_spi_disable(struct stm32_spi_priv *priv)
+{
+ debug("%s\n", __func__);
+
+ /* Disable the SPI hardware */
+ clrbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
+
+ return 0;
+}
+
+static int stm32_spi_claim_bus(struct udevice *slave)
+{
+ struct udevice *bus = dev_get_parent(slave);
+ struct stm32_spi_priv *priv = dev_get_priv(bus);
+
+ debug("%s\n", __func__);
+
+ /* Enable the SPI hardware */
+ return stm32_spi_enable(priv);
+}
+
+static int stm32_spi_release_bus(struct udevice *slave)
+{
+ struct udevice *bus = dev_get_parent(slave);
+ struct stm32_spi_priv *priv = dev_get_priv(bus);
+
+ debug("%s\n", __func__);
+
+ /* Disable the SPI hardware */
+ return stm32_spi_disable(priv);
+}
+
+static void stm32_spi_stopxfer(struct udevice *dev)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+ u32 cr1, sr;
+ int ret;
+
+ debug("%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), 100000);
+ 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 int stm32_spi_set_cs(struct udevice *dev, unsigned int cs, bool enable)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+
+ debug("%s: cs=%d enable=%d\n", __func__, cs, enable);
+
+ if (cs >= MAX_CS_COUNT)
+ return -ENODEV;
+
+ if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
+ return -EINVAL;
+
+ if (priv->cs_high)
+ enable = !enable;
+
+ return dm_gpio_set_value(&priv->cs_gpios[cs], enable ? 1 : 0);
+}
+
+static int stm32_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(bus);
+ u32 cfg2_clrb = 0, cfg2_setb = 0;
+
+ debug("%s: mode=%d\n", __func__, 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);
+
+ if (mode & SPI_CS_HIGH)
+ priv->cs_high = true;
+ else
+ priv->cs_high = false;
+ return 0;
+}
+
+static int stm32_spi_set_fthlv(struct udevice *dev, u32 xfer_len)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+ 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);
+
+ return 0;
+}
+
+static int stm32_spi_set_speed(struct udevice *bus, uint hz)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(bus);
+ u32 div, mbrdiv;
+
+ debug("%s: hz=%d\n", __func__, 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 - 1) < 0)
+ 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_xfer(struct udevice *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev_get_parent(slave);
+ struct dm_spi_slave_platdata *slave_plat;
+ struct stm32_spi_priv *priv = dev_get_priv(bus);
+ u32 sr;
+ u32 ifcr = 0;
+ u32 xferlen;
+ u32 mode;
+ int xfer_status = 0;
+
+ xferlen = bitlen / 8;
+
+ if (xferlen <= SPI_CR2_TSIZE)
+ writel(xferlen, priv->base + STM32_SPI_CR2);
+ else
+ return -EMSGSIZE;
+
+ priv->tx_buf = dout;
+ priv->rx_buf = din;
+ priv->tx_len = priv->tx_buf ? bitlen / 8 : 0;
+ priv->rx_len = priv->rx_buf ? bitlen / 8 : 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 != xferlen || priv->cur_mode != mode) {
+ priv->cur_mode = mode;
+ priv->cur_xferlen = xferlen;
+
+ /* 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(bus, xferlen);
+
+ /* Enable the SPI hardware */
+ stm32_spi_enable(priv);
+ }
+
+ debug("%s: priv->tx_len=%d priv->rx_len=%d\n", __func__,
+ priv->tx_len, priv->rx_len);
+
+ slave_plat = dev_get_parent_platdata(slave);
+ if (flags & SPI_XFER_BEGIN)
+ stm32_spi_set_cs(bus, slave_plat->cs, false);
+
+ /* 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(bus, "Overrun: RX data lost\n");
+ xfer_status = -EIO;
+ break;
+ }
+
+ if (sr & SPI_SR_SUSP) {
+ dev_warn(bus, "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(bus);
+
+ if (flags & SPI_XFER_END)
+ stm32_spi_set_cs(bus, slave_plat->cs, true);
+
+ return xfer_status;
+}
+
+static int stm32_spi_get_fifo_size(struct udevice *dev)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+ 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);
+
+ debug("%s %d x 8-bit fifo size\n", __func__, count);
+
+ return count;
+}
+
+static int stm32_spi_probe(struct udevice *dev)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+ unsigned long clk_rate;
+ int ret;
+ int i;
+
+ priv->base = dev_remap_addr(dev);
+ if (!priv->base)
+ return -EINVAL;
+
+ /* enable clock */
+ ret = clk_get_by_index(dev, 0, &priv->clk);
+ if (ret < 0)
+ return ret;
+
+ ret = clk_enable(&priv->clk);
+ if (ret < 0)
+ return ret;
+
+ clk_rate = clk_get_rate(&priv->clk);
+ if (!clk_rate) {
+ ret = -EINVAL;
+ goto clk_err;
+ }
+
+ priv->bus_clk_rate = clk_rate;
+
+ /* perform reset */
+ ret = reset_get_by_index(dev, 0, &priv->rst_ctl);
+ if (ret < 0)
+ goto clk_err;
+
+ reset_assert(&priv->rst_ctl);
+ udelay(2);
+ reset_deassert(&priv->rst_ctl);
+
+ ret = gpio_request_list_by_name(dev, "cs-gpios", priv->cs_gpios,
+ ARRAY_SIZE(priv->cs_gpios), 0);
+ if (ret < 0) {
+ pr_err("Can't get %s cs gpios: %d", dev->name, ret);
+ goto reset_err;
+ }
+
+ priv->fifo_size = stm32_spi_get_fifo_size(dev);
+
+ priv->cur_mode = SPI_FULL_DUPLEX;
+ priv->cur_xferlen = 0;
+ priv->cur_bpw = SPI_DEFAULT_WORDLEN;
+ clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_DSIZE,
+ priv->cur_bpw - 1);
+
+ for (i = 0; i < ARRAY_SIZE(priv->cs_gpios); i++) {
+ if (!dm_gpio_is_valid(&priv->cs_gpios[i]))
+ continue;
+
+ dm_gpio_set_dir_flags(&priv->cs_gpios[i],
+ GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+ }
+
+ /* 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 0;
+
+reset_err:
+ reset_free(&priv->rst_ctl);
+
+clk_err:
+ clk_disable(&priv->clk);
+ clk_free(&priv->clk);
+
+ return ret;
+};
+
+static int stm32_spi_remove(struct udevice *dev)
+{
+ struct stm32_spi_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ stm32_spi_stopxfer(dev);
+ stm32_spi_disable(priv);
+
+ ret = reset_assert(&priv->rst_ctl);
+ if (ret < 0)
+ return ret;
+
+ reset_free(&priv->rst_ctl);
+
+ ret = clk_disable(&priv->clk);
+ if (ret < 0)
+ return ret;
+
+ clk_free(&priv->clk);
+
+ return ret;
+};
+
+static const struct dm_spi_ops stm32_spi_ops = {
+ .claim_bus = stm32_spi_claim_bus,
+ .release_bus = stm32_spi_release_bus,
+ .set_mode = stm32_spi_set_mode,
+ .set_speed = stm32_spi_set_speed,
+ .xfer = stm32_spi_xfer,
+};
+
+static const struct udevice_id stm32_spi_ids[] = {
+ { .compatible = "st,stm32h7-spi", },
+ { }
+};
+
+U_BOOT_DRIVER(stm32_spi) = {
+ .name = "stm32_spi",
+ .id = UCLASS_SPI,
+ .of_match = stm32_spi_ids,
+ .ops = &stm32_spi_ops,
+ .priv_auto_alloc_size = sizeof(struct stm32_spi_priv),
+ .probe = stm32_spi_probe,
+ .remove = stm32_spi_remove,
+};
projects / u-boot.git / commitdiff