[PATCH 3/5] spi: Add support for Renesas CSI
From: Fabrizio Castro
Date: Wed Jun 21 2023 - 10:10:41 EST
The RZ/V2M SoC comes with the Clocked Serial Interface (CSI)
IP, which is a master/slave SPI controller.
This commit adds a driver to support CSI master mode.
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-rzv2m-csi.c | 667 ++++++++++++++++++++++++++++++++++++
3 files changed, 674 insertions(+)
create mode 100644 drivers/spi/spi-rzv2m-csi.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 14810d24733b..abbd1fb5fbc0 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -825,6 +825,12 @@ config SPI_RSPI
help
SPI driver for Renesas RSPI and QSPI blocks.
+config SPI_RZV2M_CSI
+ tristate "Renesas RZV2M CSI controller"
+ depends on ARCH_RENESAS || COMPILE_TEST
+ help
+ SPI driver for Renesas RZ/V2M Clocked Serial Interface (CSI)
+
config SPI_QCOM_QSPI
tristate "QTI QSPI controller"
depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 28c4817a8a74..080c2c1b3ec1 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -113,6 +113,7 @@ obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o
obj-$(CONFIG_MACH_REALTEK_RTL) += spi-realtek-rtl.o
obj-$(CONFIG_SPI_RPCIF) += spi-rpc-if.o
obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
+obj-$(CONFIG_SPI_RZV2M_CSI) += spi-rzv2m-csi.o
obj-$(CONFIG_SPI_S3C64XX) += spi-s3c64xx.o
obj-$(CONFIG_SPI_SC18IS602) += spi-sc18is602.o
obj-$(CONFIG_SPI_SH) += spi-sh.o
diff --git a/drivers/spi/spi-rzv2m-csi.c b/drivers/spi/spi-rzv2m-csi.c
new file mode 100644
index 000000000000..7fbecff229f4
--- /dev/null
+++ b/drivers/spi/spi-rzv2m-csi.c
@@ -0,0 +1,667 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Renesas RZ/V2M Clocked Serial Interface (CSI) driver
+ *
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/count_zeros.h>
+#include <linux/iopoll.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+
+/* Registers */
+#define CSI_MODE 0x00 /* CSI mode control */
+#define CSI_CLKSEL 0x04 /* CSI clock select */
+#define CSI_CNT 0x08 /* CSI control */
+#define CSI_INT 0x0C /* CSI interrupt status */
+#define CSI_IFIFOL 0x10 /* CSI receive FIFO level display */
+#define CSI_OFIFOL 0x14 /* CSI transmit FIFO level display */
+#define CSI_IFIFO 0x18 /* CSI receive window */
+#define CSI_OFIFO 0x1C /* CSI transmit window */
+#define CSI_FIFOTRG 0x20 /* CSI FIFO trigger level */
+
+/* CSI_MODE */
+#define CSI_MODE_CSIE BIT(7)
+#define CSI_MODE_TRMD BIT(6)
+#define CSI_MODE_CCL BIT(5)
+#define CSI_MODE_DIR BIT(4)
+#define CSI_MODE_CSOT BIT(0)
+
+#define CSI_MODE_SETUP 0x00000040
+
+/* CSI_CLKSEL */
+#define CSI_CLKSEL_CKP BIT(17)
+#define CSI_CLKSEL_DAP BIT(16)
+#define CSI_CLKSEL_SLAVE BIT(15)
+#define CSI_CLKSEL_CKS GENMASK(14, 1)
+
+/* CSI_CNT */
+#define CSI_CNT_CSIRST BIT(28)
+#define CSI_CNT_R_TRGEN BIT(19)
+#define CSI_CNT_UNDER_E BIT(13)
+#define CSI_CNT_OVERF_E BIT(12)
+#define CSI_CNT_TREND_E BIT(9)
+#define CSI_CNT_CSIEND_E BIT(8)
+#define CSI_CNT_T_TRGR_E BIT(4)
+#define CSI_CNT_R_TRGR_E BIT(0)
+
+/* CSI_INT */
+#define CSI_INT_UNDER BIT(13)
+#define CSI_INT_OVERF BIT(12)
+#define CSI_INT_TREND BIT(9)
+#define CSI_INT_CSIEND BIT(8)
+#define CSI_INT_T_TRGR BIT(4)
+#define CSI_INT_R_TRGR BIT(0)
+
+/* CSI_FIFOTRG */
+#define CSI_FIFOTRG_R_TRG GENMASK(2, 0)
+
+#define CSI_FIFO_SIZE_BYTES 32
+#define CSI_FIFO_HALF_SIZE 16
+#define CSI_EN_DIS_TIMEOUT_US 100
+#define CSI_CKS_MAX 0x3FFF
+
+#define UNDERRUN_ERROR BIT(0)
+#define OVERFLOW_ERROR BIT(1)
+#define TX_TIMEOUT_ERROR BIT(2)
+#define RX_TIMEOUT_ERROR BIT(3)
+
+#define CSI_MAX_SPI_SCKO 8000000
+
+struct rzv2m_csi_priv {
+ void __iomem *base;
+ struct clk *csiclk;
+ struct clk *pclk;
+ struct device *dev;
+ struct spi_controller *controller;
+ const u8 *txbuf;
+ u8 *rxbuf;
+ int buffer_len;
+ int bytes_sent;
+ int bytes_received;
+ int bytes_to_transfer;
+ int words_to_transfer;
+ unsigned char bytes_per_word;
+ wait_queue_head_t wait;
+ u8 errors;
+ u32 status;
+};
+
+static const unsigned char x_trg[] = {
+ 0, 1, 1, 2, 2, 2, 2, 3,
+ 3, 3, 3, 3, 3, 3, 3, 4,
+ 4, 4, 4, 4, 4, 4, 4, 4,
+ 4, 4, 4, 4, 4, 4, 4, 5
+};
+
+static const unsigned char x_trg_words[] = {
+ 1, 2, 2, 4, 4, 4, 4, 8,
+ 8, 8, 8, 8, 8, 8, 8, 16,
+ 16, 16, 16, 16, 16, 16, 16, 16,
+ 16, 16, 16, 16, 16, 16, 16, 32
+};
+
+static void rzv2m_csi_reg_write_bit(const struct rzv2m_csi_priv *csi,
+ int reg_offs, int bit_mask, u32 value)
+{
+ int nr_zeros;
+ u32 tmp;
+
+ nr_zeros = count_trailing_zeros(bit_mask);
+ value <<= nr_zeros;
+
+ tmp = (readl(csi->base + reg_offs) & ~bit_mask) | value;
+ writel(tmp, csi->base + reg_offs);
+}
+
+static int rzv2m_csi_sw_reset(struct rzv2m_csi_priv *csi, int assert)
+{
+ u32 reg;
+
+ rzv2m_csi_reg_write_bit(csi, CSI_CNT, CSI_CNT_CSIRST, assert);
+
+ if (assert) {
+ return readl_poll_timeout(csi->base + CSI_MODE, reg,
+ !(reg & CSI_MODE_CSOT), 0,
+ CSI_EN_DIS_TIMEOUT_US);
+ }
+
+ return 0;
+}
+
+static int rzv2m_csi_start_stop_operation(const struct rzv2m_csi_priv *csi,
+ int enable, bool wait)
+{
+ u32 reg;
+
+ rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_CSIE, enable);
+
+ if (!enable && wait)
+ return readl_poll_timeout(csi->base + CSI_MODE, reg,
+ !(reg & CSI_MODE_CSOT), 0,
+ CSI_EN_DIS_TIMEOUT_US);
+
+ return 0;
+}
+
+static int rzv2m_csi_fill_txfifo(struct rzv2m_csi_priv *csi)
+{
+ int i;
+
+ if (readl(csi->base + CSI_OFIFOL))
+ return -EIO;
+
+ if (csi->bytes_per_word == 2) {
+ u16 *buf = (u16 *)csi->txbuf;
+
+ for (i = 0; i < csi->words_to_transfer; i++)
+ writel(buf[i], csi->base + CSI_OFIFO);
+ } else {
+ u8 *buf = (u8 *)csi->txbuf;
+
+ for (i = 0; i < csi->words_to_transfer; i++)
+ writel(buf[i], csi->base + CSI_OFIFO);
+ }
+
+ csi->txbuf += csi->bytes_to_transfer;
+ csi->bytes_sent += csi->bytes_to_transfer;
+
+ return 0;
+}
+
+static int rzv2m_csi_read_rxfifo(struct rzv2m_csi_priv *csi)
+{
+ int i;
+
+ if (readl(csi->base + CSI_IFIFOL) != csi->bytes_to_transfer)
+ return -EIO;
+
+ if (csi->bytes_per_word == 2) {
+ u16 *buf = (u16 *)csi->rxbuf;
+
+ for (i = 0; i < csi->words_to_transfer; i++)
+ buf[i] = (u16)readl(csi->base + CSI_IFIFO);
+ } else {
+ u8 *buf = (u8 *)csi->rxbuf;
+
+ for (i = 0; i < csi->words_to_transfer; i++)
+ buf[i] = (u8)readl(csi->base + CSI_IFIFO);
+ }
+
+ csi->rxbuf += csi->bytes_to_transfer;
+ csi->bytes_received += csi->bytes_to_transfer;
+
+ return 0;
+}
+
+static inline void rzv2m_csi_calc_current_transfer(struct rzv2m_csi_priv *csi)
+{
+ int bytes_transferred = max_t(int, csi->bytes_received, csi->bytes_sent);
+ int bytes_remaining = csi->buffer_len - bytes_transferred;
+ int to_transfer;
+
+ if (csi->txbuf)
+ /*
+ * Leaving a little bit of headroom in the FIFOs makes it very
+ * hard to raise an overflow error (which is only possible
+ * when IP transmits and receives at the same time).
+ */
+ to_transfer = min_t(int, CSI_FIFO_HALF_SIZE, bytes_remaining);
+ else
+ to_transfer = min_t(int, CSI_FIFO_SIZE_BYTES, bytes_remaining);
+
+ if (csi->bytes_per_word == 2)
+ to_transfer >>= 1;
+
+ /*
+ * We can only choose a trigger level from a predefined set of values.
+ * This will pick a value that is the greatest possible integer that's
+ * less than or equal to the number of bytes we need to transfer.
+ * This may result in multiple smaller transfers.
+ */
+ csi->words_to_transfer = x_trg_words[to_transfer - 1];
+
+ if (csi->bytes_per_word == 2)
+ csi->bytes_to_transfer = csi->words_to_transfer << 1;
+ else
+ csi->bytes_to_transfer = csi->words_to_transfer;
+}
+
+static inline void rzv2m_csi_set_rx_fifo_trigger_level(struct rzv2m_csi_priv *csi)
+{
+ rzv2m_csi_reg_write_bit(csi, CSI_FIFOTRG, CSI_FIFOTRG_R_TRG,
+ x_trg[csi->words_to_transfer - 1]);
+}
+
+static inline void rzv2m_csi_enable_rx_trigger(struct rzv2m_csi_priv *csi,
+ bool enable)
+{
+ rzv2m_csi_reg_write_bit(csi, CSI_CNT, CSI_CNT_R_TRGEN, enable);
+}
+
+static void rzv2m_csi_disable_irqs(const struct rzv2m_csi_priv *csi,
+ u32 enable_bits)
+{
+ u32 cnt = readl(csi->base + CSI_CNT);
+
+ writel(cnt & ~enable_bits, csi->base + CSI_CNT);
+}
+
+static void rzv2m_csi_disable_all_irqs(struct rzv2m_csi_priv *csi)
+{
+ rzv2m_csi_disable_irqs(csi, CSI_CNT_R_TRGR_E | CSI_CNT_T_TRGR_E |
+ CSI_CNT_CSIEND_E | CSI_CNT_TREND_E |
+ CSI_CNT_OVERF_E | CSI_CNT_UNDER_E);
+}
+
+static inline void rzv2m_csi_clear_irqs(struct rzv2m_csi_priv *csi, u32 irqs)
+{
+ writel(irqs, csi->base + CSI_INT);
+}
+
+static void rzv2m_csi_clear_all_irqs(struct rzv2m_csi_priv *csi)
+{
+ rzv2m_csi_clear_irqs(csi, CSI_INT_UNDER | CSI_INT_OVERF |
+ CSI_INT_TREND | CSI_INT_CSIEND | CSI_INT_T_TRGR |
+ CSI_INT_R_TRGR);
+}
+
+static void rzv2m_csi_enable_irqs(struct rzv2m_csi_priv *csi, u32 enable_bits)
+{
+ u32 cnt = readl(csi->base + CSI_CNT);
+
+ writel(cnt | enable_bits, csi->base + CSI_CNT);
+}
+
+static int rzv2m_csi_wait_for_interrupt(struct rzv2m_csi_priv *csi,
+ u32 wait_mask, u32 enable_bits)
+{
+ int ret;
+
+ rzv2m_csi_enable_irqs(csi, enable_bits);
+
+ ret = wait_event_timeout(csi->wait,
+ ((csi->status & wait_mask) == wait_mask) ||
+ csi->errors, HZ);
+
+ rzv2m_csi_disable_irqs(csi, enable_bits);
+
+ if (csi->errors)
+ return -EIO;
+
+ if (!ret)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int rzv2m_csi_wait_for_tx_empty(struct rzv2m_csi_priv *csi)
+{
+ int ret;
+
+ if (readl(csi->base + CSI_OFIFOL) == 0)
+ return 0;
+
+ ret = rzv2m_csi_wait_for_interrupt(csi, CSI_INT_TREND, CSI_CNT_TREND_E);
+
+ if (ret == -ETIMEDOUT)
+ csi->errors |= TX_TIMEOUT_ERROR;
+
+ return ret;
+}
+
+static inline int rzv2m_csi_wait_for_rx_ready(struct rzv2m_csi_priv *csi)
+{
+ int ret;
+
+ if (readl(csi->base + CSI_IFIFOL) == csi->bytes_to_transfer)
+ return 0;
+
+ ret = rzv2m_csi_wait_for_interrupt(csi, CSI_INT_R_TRGR,
+ CSI_CNT_R_TRGR_E);
+
+ if (ret == -ETIMEDOUT)
+ csi->errors |= RX_TIMEOUT_ERROR;
+
+ return ret;
+}
+
+static irqreturn_t rzv2m_csi_irq_handler(int irq, void *data)
+{
+ struct rzv2m_csi_priv *csi = (struct rzv2m_csi_priv *)data;
+
+ csi->status = readl(csi->base + CSI_INT);
+ rzv2m_csi_disable_irqs(csi, csi->status);
+
+ if (csi->status & CSI_INT_OVERF)
+ csi->errors |= OVERFLOW_ERROR;
+ if (csi->status & CSI_INT_UNDER)
+ csi->errors |= UNDERRUN_ERROR;
+
+ wake_up(&csi->wait);
+
+ return IRQ_HANDLED;
+}
+
+static void rzv2m_csi_setup_clock(struct rzv2m_csi_priv *csi, u32 spi_hz)
+{
+ unsigned long csiclk_rate = clk_get_rate(csi->csiclk);
+ unsigned long pclk_rate = clk_get_rate(csi->pclk);
+ unsigned long csiclk_rate_limit = pclk_rate >> 1;
+ u32 cks;
+
+ /*
+ * There is a restriction on the frequency of CSICLK, it has to be <=
+ * PCLK / 2.
+ */
+ if (csiclk_rate > csiclk_rate_limit) {
+ clk_set_rate(csi->csiclk, csiclk_rate >> 1);
+ csiclk_rate = clk_get_rate(csi->csiclk);
+ } else if ((csiclk_rate << 1) <= csiclk_rate_limit) {
+ clk_set_rate(csi->csiclk, csiclk_rate << 1);
+ csiclk_rate = clk_get_rate(csi->csiclk);
+ }
+
+ spi_hz = spi_hz > CSI_MAX_SPI_SCKO ? CSI_MAX_SPI_SCKO : spi_hz;
+
+ cks = DIV_ROUND_UP(csiclk_rate, spi_hz << 1);
+ if (cks > CSI_CKS_MAX)
+ cks = CSI_CKS_MAX;
+
+ dev_dbg(csi->dev, "SPI clk rate is %ldHz\n", csiclk_rate / (cks << 1));
+
+ rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_CKS, cks);
+}
+
+static void rzv2m_csi_setup_operating_mode(struct rzv2m_csi_priv *csi,
+ struct spi_transfer *t)
+{
+ if (t->rx_buf && !t->tx_buf)
+ /* Reception-only mode */
+ rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_TRMD, 0);
+ else
+ /* Send and receive mode */
+ rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_TRMD, 1);
+
+ csi->bytes_per_word = t->bits_per_word / 8;
+ rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_CCL,
+ csi->bytes_per_word == 2);
+}
+
+static int rzv2m_csi_setup(struct spi_device *spi)
+{
+ struct rzv2m_csi_priv *csi = spi_controller_get_devdata(spi->controller);
+ int ret;
+
+ rzv2m_csi_sw_reset(csi, 0);
+
+ writel(CSI_MODE_SETUP, csi->base + CSI_MODE);
+
+ /* Setup clock polarity and phase timing */
+ rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_CKP,
+ !(spi->mode & SPI_CPOL));
+ rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_DAP,
+ !(spi->mode & SPI_CPHA));
+
+ /* Setup serial data order */
+ rzv2m_csi_reg_write_bit(csi, CSI_MODE, CSI_MODE_DIR,
+ !!(spi->mode & SPI_LSB_FIRST));
+
+ /* Set the operation mode as master */
+ rzv2m_csi_reg_write_bit(csi, CSI_CLKSEL, CSI_CLKSEL_SLAVE, 0);
+
+ /* Give the IP a SW reset */
+ ret = rzv2m_csi_sw_reset(csi, 1);
+ if (ret)
+ return ret;
+ rzv2m_csi_sw_reset(csi, 0);
+
+ /*
+ * We need to enable the communication so that the clock will settle
+ * for the right polarity before enabling the CS.
+ */
+ rzv2m_csi_start_stop_operation(csi, 1, false);
+ udelay(10);
+ rzv2m_csi_start_stop_operation(csi, 0, false);
+
+ return 0;
+}
+
+static int rzv2m_csi_pio_transfer(struct rzv2m_csi_priv *csi)
+{
+ bool tx_completed = csi->txbuf ? false : true;
+ bool rx_completed = csi->rxbuf ? false : true;
+ int ret = 0;
+
+ /* Make sure the TX FIFO is empty */
+ writel(0, csi->base + CSI_OFIFOL);
+
+ csi->bytes_sent = 0;
+ csi->bytes_received = 0;
+ csi->errors = 0;
+
+ rzv2m_csi_disable_all_irqs(csi);
+ rzv2m_csi_clear_all_irqs(csi);
+ rzv2m_csi_enable_rx_trigger(csi, true);
+
+ while (!tx_completed || !rx_completed) {
+ /*
+ * Decide how many words we are going to transfer during
+ * this cycle (for both TX and RX), then set the RX FIFO trigger
+ * level accordingly. No need to set a trigger level for the
+ * TX FIFO, as this IP comes with an interrupt that fires when
+ * the TX FIFO is empty.
+ */
+ rzv2m_csi_calc_current_transfer(csi);
+ rzv2m_csi_set_rx_fifo_trigger_level(csi);
+
+ rzv2m_csi_enable_irqs(csi, CSI_INT_OVERF | CSI_INT_UNDER);
+
+ /* Make sure the RX FIFO is empty */
+ writel(0, csi->base + CSI_IFIFOL);
+
+ writel(readl(csi->base + CSI_INT), csi->base + CSI_INT);
+ csi->status = 0;
+
+ rzv2m_csi_start_stop_operation(csi, 1, false);
+
+ /* TX */
+ if (csi->txbuf) {
+ ret = rzv2m_csi_fill_txfifo(csi);
+ if (ret)
+ break;
+
+ ret = rzv2m_csi_wait_for_tx_empty(csi);
+ if (ret)
+ break;
+
+ if (csi->bytes_sent == csi->buffer_len)
+ tx_completed = true;
+ }
+
+ /*
+ * Make sure the RX FIFO contains the desired number of words.
+ * We then either flush its content, or we copy it onto
+ * csi->rxbuf.
+ */
+ ret = rzv2m_csi_wait_for_rx_ready(csi);
+ if (ret)
+ break;
+
+ /* RX */
+ if (csi->rxbuf) {
+ rzv2m_csi_start_stop_operation(csi, 0, false);
+
+ ret = rzv2m_csi_read_rxfifo(csi);
+ if (ret)
+ break;
+
+ if (csi->bytes_received == csi->buffer_len)
+ rx_completed = true;
+ }
+
+ ret = rzv2m_csi_start_stop_operation(csi, 0, true);
+ if (ret)
+ goto pio_quit;
+
+ if (csi->errors) {
+ ret = -EIO;
+ goto pio_quit;
+ }
+ }
+
+ rzv2m_csi_start_stop_operation(csi, 0, true);
+
+pio_quit:
+ rzv2m_csi_disable_all_irqs(csi);
+ rzv2m_csi_enable_rx_trigger(csi, false);
+ rzv2m_csi_clear_all_irqs(csi);
+
+ return ret;
+}
+
+static int rzv2m_csi_transfer_one(struct spi_controller *controller,
+ struct spi_device *spi,
+ struct spi_transfer *transfer)
+{
+ struct rzv2m_csi_priv *csi = spi_controller_get_devdata(controller);
+ struct device *dev = csi->dev;
+ int ret;
+
+ csi->txbuf = transfer->tx_buf;
+ csi->rxbuf = transfer->rx_buf;
+ csi->buffer_len = transfer->len;
+
+ rzv2m_csi_setup_operating_mode(csi, transfer);
+
+ rzv2m_csi_setup_clock(csi, transfer->speed_hz);
+
+ ret = rzv2m_csi_pio_transfer(csi);
+ if (ret) {
+ if (csi->errors & UNDERRUN_ERROR)
+ dev_err(dev, "Underrun error\n");
+ if (csi->errors & OVERFLOW_ERROR)
+ dev_err(dev, "Overflow error\n");
+ if (csi->errors & TX_TIMEOUT_ERROR)
+ dev_err(dev, "TX timeout error\n");
+ if (csi->errors & RX_TIMEOUT_ERROR)
+ dev_err(dev, "RX timeout error\n");
+ }
+
+ return ret;
+}
+
+static int rzv2m_csi_probe(struct platform_device *pdev)
+{
+ struct spi_controller *controller;
+ struct device *dev = &pdev->dev;
+ struct rzv2m_csi_priv *csi;
+ struct reset_control *rstc;
+ int irq;
+ int ret;
+
+ controller = devm_spi_alloc_master(dev, sizeof(*csi));
+ if (!controller)
+ return -ENOMEM;
+
+ csi = spi_controller_get_devdata(controller);
+ platform_set_drvdata(pdev, csi);
+
+ csi->dev = dev;
+ csi->controller = controller;
+
+ csi->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(csi->base))
+ return PTR_ERR(csi->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ csi->csiclk = devm_clk_get(dev, "csiclk");
+ if (IS_ERR(csi->csiclk))
+ return dev_err_probe(dev, PTR_ERR(csi->csiclk),
+ "could not get csiclk\n");
+
+ csi->pclk = devm_clk_get(dev, "pclk");
+ if (IS_ERR(csi->pclk))
+ return dev_err_probe(dev, PTR_ERR(csi->pclk),
+ "could not get pclk\n");
+
+ rstc = devm_reset_control_get_shared(dev, NULL);
+ if (IS_ERR(rstc))
+ return dev_err_probe(dev, PTR_ERR(rstc), "Missing reset ctrl\n");
+
+ init_waitqueue_head(&csi->wait);
+
+ controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
+ controller->dev.of_node = pdev->dev.of_node;
+ controller->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
+ controller->setup = rzv2m_csi_setup;
+ controller->transfer_one = rzv2m_csi_transfer_one;
+ controller->use_gpio_descriptors = true;
+
+ ret = devm_request_irq(dev, irq, rzv2m_csi_irq_handler, 0,
+ dev_name(dev), csi);
+ if (ret)
+ return dev_err_probe(dev, ret, "cannot request IRQ\n");
+
+ /*
+ * The reset also affects other HW that is not under the control
+ * of Linux. Therefore, all we can do is make sure the reset is
+ * deasserted.
+ */
+ reset_control_deassert(rstc);
+
+ /* Make sure the IP is in SW reset state */
+ ret = rzv2m_csi_sw_reset(csi, 1);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(csi->csiclk);
+ if (ret)
+ return dev_err_probe(dev, ret, "could not enable csiclk\n");
+
+ ret = spi_register_controller(controller);
+ if (ret) {
+ clk_disable_unprepare(csi->csiclk);
+ return dev_err_probe(dev, ret, "register controller failed\n");
+ }
+
+ return 0;
+}
+
+static int rzv2m_csi_remove(struct platform_device *pdev)
+{
+ struct rzv2m_csi_priv *csi = platform_get_drvdata(pdev);
+
+ spi_unregister_controller(csi->controller);
+ rzv2m_csi_sw_reset(csi, 1);
+ clk_disable_unprepare(csi->csiclk);
+
+ return 0;
+}
+
+static const struct of_device_id rzv2m_csi_match[] = {
+ { .compatible = "renesas,rzv2m-csi" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzv2m_csi_match);
+
+static struct platform_driver rzv2m_csi_drv = {
+ .probe = rzv2m_csi_probe,
+ .remove = rzv2m_csi_remove,
+ .driver = {
+ .name = "rzv2m_csi",
+ .of_match_table = rzv2m_csi_match,
+ },
+};
+module_platform_driver(rzv2m_csi_drv);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fabrizio Castro <castro.fabrizio.jz@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Clocked Serial Interface Driver");
--
2.34.1