* [PATCH 2/2] spi: atcspi200: Add ATCSPI200 SPI driver
2025-11-12 3:47 [PATCH 0/2] spi: atcspi200: Add support for Andes ATCSPI200 SPI controller CL Wang
2025-11-12 3:47 ` [PATCH 1/2] dt-bindings: spi: Add support for " CL Wang
@ 2025-11-12 3:47 ` CL Wang
2025-11-14 11:58 ` Krzysztof Kozlowski
1 sibling, 1 reply; 7+ messages in thread
From: CL Wang @ 2025-11-12 3:47 UTC (permalink / raw)
To: cl634, broonie, linux-spi, robh, krzk+dt, conor+dt
Cc: devicetree, linux-kernel, tim609
SPI driver for Andes ATCSPI200 SPI controller.
Signed-off-by: CL Wang <cl634@andestech.com>
---
drivers/spi/Kconfig | 9 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-atcspi200.c | 651 ++++++++++++++++++++++++++++++++++++
3 files changed, 661 insertions(+)
create mode 100644 drivers/spi/spi-atcspi200.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 592d46c9998b..b2e35f55aa88 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -136,6 +136,15 @@ config SPI_AR934X
This enables support for the SPI controller present on the
Qualcomm Atheros AR934X/QCA95XX SoCs.
+config SPI_ATCSPI200
+ tristate "Andes ATCSPI200 SPI controller"
+ depends on ARCH_ANDES
+ help
+ SPI driver for Andes ATCSPI200 SPI controller.
+ ATCSPI200 controller supports DMA and PIO modes. When DMA
+ is not available, the driver automatically falls back to
+ PIO mode.
+
config SPI_ATH79
tristate "Atheros AR71XX/AR724X/AR913X SPI controller driver"
depends on ATH79 || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 8ff74a13faaa..869d6fbc53f8 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_SPI_APPLE) += spi-apple.o
obj-$(CONFIG_SPI_AR934X) += spi-ar934x.o
obj-$(CONFIG_SPI_ARMADA_3700) += spi-armada-3700.o
obj-$(CONFIG_SPI_ASPEED_SMC) += spi-aspeed-smc.o
+obj-$(CONFIG_SPI_ATCSPI200) += spi-atcspi200.o
obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o
obj-$(CONFIG_SPI_ATMEL_QUADSPI) += atmel-quadspi.o
obj-$(CONFIG_SPI_AT91_USART) += spi-at91-usart.o
diff --git a/drivers/spi/spi-atcspi200.c b/drivers/spi/spi-atcspi200.c
new file mode 100644
index 000000000000..65ffbaaf9124
--- /dev/null
+++ b/drivers/spi/spi-atcspi200.c
@@ -0,0 +1,651 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Andes ATCSPI200 SPI Controller
+ *
+ * Copyright (C) 2025 Andes Technology Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dev_printk.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+/* Register definitions */
+#define ATCSPI_TRANS_FMT 0x10 /* SPI transfer format register */
+#define ATCSPI_TRANS_CTRL 0x20 /* SPI transfer control register */
+#define ATCSPI_CMD 0x24 /* SPI command register */
+#define ATCSPI_ADDR 0x28 /* SPI address register */
+#define ATCSPI_DATA 0x2C /* SPI data register */
+#define ATCSPI_CTRL 0x30 /* SPI control register */
+#define ATCSPI_STATUS 0x34 /* SPI status register */
+#define ATCSPI_TIMING 0x40 /* SPI interface timing register */
+#define ATCSPI_CONFIG 0x7C /* SPI configuration register */
+
+/* Transfer format register */
+#define TRANS_FMT_CPHA BIT(0)
+#define TRANS_FMT_CPOL BIT(1)
+#define TRANS_FMT_DATA_MERGE_EN BIT(7)
+#define TRANS_FMT_DATA_LEN_MASK GENMASK(12, 8)
+#define TRANS_FMT_ADDR_LEN_MASK GENMASK(17, 16)
+#define TRANS_FMT_DATA_LEN(x) FIELD_PREP(TRANS_FMT_DATA_LEN_MASK, (x) - 1)
+#define TRANS_FMT_ADDR_LEN(x) FIELD_PREP(TRANS_FMT_ADDR_LEN_MASK, (x) - 1)
+
+/* Transfer control register */
+#define TRANS_MODE_MASK GENMASK(27, 24)
+#define TRANS_MODE_W_ONLY FIELD_PREP(TRANS_MODE_MASK, 1)
+#define TRANS_MODE_R_ONLY FIELD_PREP(TRANS_MODE_MASK, 2)
+#define TRANS_MODE_NONE_DATA FIELD_PREP(TRANS_MODE_MASK, 7)
+#define TRANS_MODE_DMY_READ FIELD_PREP(TRANS_MODE_MASK, 9)
+#define TRANS_FIELD_DECNZ(m, x) ((x) ? FIELD_PREP(m, (x) - 1) : 0)
+#define TRANS_RD_TRANS_CNT(x) TRANS_FIELD_DECNZ(GENMASK(8, 0), x)
+#define TRANS_DUMMY_CNT(x) TRANS_FIELD_DECNZ(GENMASK(10, 9), x)
+#define TRANS_WR_TRANS_CNT(x) TRANS_FIELD_DECNZ(GENMASK(20, 12), x)
+#define TRANS_DUAL_QUAD(x) FIELD_PREP(GENMASK(23, 22), (x))
+#define TRANS_ADDR_FMT BIT(28)
+#define TRANS_ADDR_EN BIT(29)
+#define TRANS_CMD_EN BIT(30)
+
+/* Control register */
+#define CTRL_SPI_RST BIT(0)
+#define CTRL_RX_FIFO_RST BIT(1)
+#define CTRL_TX_FIFO_RST BIT(2)
+#define CTRL_RX_DMA_EN BIT(3)
+#define CTRL_TX_DMA_EN BIT(4)
+
+/* Status register */
+#define ATCSPI_ACTIVE BIT(0)
+#define ATCSPI_RX_EMPTY BIT(14)
+#define ATCSPI_TX_FULL BIT(23)
+
+/* Interface timing setting */
+#define TIMING_SCLK_DIV_MASK GENMASK(7, 0)
+#define TIMING_SCLK_DIV_MAX 0xFE
+
+/* Configuration register */
+#define RXFIFO_SIZE(x) FIELD_GET(GENMASK(3, 0), (x))
+#define TXFIFO_SIZE(x) FIELD_GET(GENMASK(7, 4), (x))
+
+/* driver configurations */
+#define ATCSPI_MAX_TRANS_LEN 512
+#define ATCSPI_MAX_SPEED_HZ 50000000
+#define ATCSPI_RDY_TIMEOUT_US 1000000
+#define ATCSPI_XFER_TIMEOUT(n) ((n) * 10)
+#define ATCSPI_MAX_CS_NUM 1
+#define ATCSPI_DMA_THRESHOLD 256
+#define ATCSPI_BITS_PER_UINT 8
+#define ATCSPI_DATA_MERGE_EN 1
+#define ATCSPI_DMA_SUPPORT 1
+
+/**
+ * struct atcspi_dev - Andes ATCSPI200 SPI controller private data
+ * @host: Pointer to the SPI controller structure.
+ * @mutex_lock: A mutex to protect concurrent access to the controller.
+ * @dma_completion: A completion to signal the end of a DMA transfer.
+ * @dev: Pointer to the device structure.
+ * @regmap: Register map for accessing controller registers.
+ * @clk: Pointer to the controller's functional clock.
+ * @dma_addr: The physical address of the SPI data register for DMA.
+ * @clk_rate: The cached frequency of the functional clock.
+ * @sclk_rate: The target frequency for the SPI clock (SCLK).
+ * @txfifo_size: The size of the transmit FIFO in bytes.
+ * @rxfifo_size: The size of the receive FIFO in bytes.
+ * @data_merge: A flag indicating if the data merge mode is enabled for
+ * the current transfer.
+ * @use_dma: Enable DMA mode if ATCSPI_DMA_SUPPORT is set and DMA is
+ * successfully configured.
+ */
+struct atcspi_dev {
+ struct spi_controller *host;
+ struct mutex mutex_lock;
+ struct completion dma_completion;
+ struct device *dev;
+ struct regmap *regmap;
+ struct clk *clk;
+ dma_addr_t dma_addr;
+ unsigned int clk_rate;
+ unsigned int sclk_rate;
+ unsigned int txfifo_size;
+ unsigned int rxfifo_size;
+ bool data_merge;
+ bool use_dma;
+};
+
+static int atcspi_wait_fifo_ready(struct atcspi_dev *spi,
+ enum spi_mem_data_dir dir)
+{
+ unsigned int val;
+ unsigned int mask;
+ int ret;
+
+ mask = (dir == SPI_MEM_DATA_OUT) ? ATCSPI_TX_FULL : ATCSPI_RX_EMPTY;
+ ret = regmap_read_poll_timeout(spi->regmap,
+ ATCSPI_STATUS,
+ val,
+ !(val & mask),
+ 0,
+ ATCSPI_RDY_TIMEOUT_US);
+ if (ret)
+ dev_info(spi->dev, "Timed out waiting for FIFO ready\n");
+
+ return ret;
+}
+
+static int atcspi_xfer_data_poll(struct atcspi_dev *spi,
+ const struct spi_mem_op *op)
+{
+ void *rx_buf = op->data.buf.in;
+ const void *tx_buf = op->data.buf.out;
+ unsigned int val;
+ int trans_bytes = op->data.nbytes;
+ int num_byte;
+ int ret = 0;
+
+ num_byte = spi->data_merge ? 4 : 1;
+ while (trans_bytes) {
+ if (op->data.dir == SPI_MEM_DATA_OUT) {
+ ret = atcspi_wait_fifo_ready(spi, SPI_MEM_DATA_OUT);
+ if (ret)
+ return ret;
+
+ if (spi->data_merge)
+ val = *(unsigned int *)tx_buf;
+ else
+ val = *(unsigned char *)tx_buf;
+ regmap_write(spi->regmap, ATCSPI_DATA, val);
+ tx_buf = (unsigned char *)tx_buf + num_byte;
+ } else {
+ ret = atcspi_wait_fifo_ready(spi, SPI_MEM_DATA_IN);
+ if (ret)
+ return ret;
+
+ regmap_read(spi->regmap, ATCSPI_DATA, &val);
+ if (spi->data_merge)
+ *(unsigned int *)rx_buf = val;
+ else
+ *(unsigned char *)rx_buf = (unsigned char)val;
+ rx_buf = (unsigned char *)rx_buf + num_byte;
+ }
+ trans_bytes -= num_byte;
+ }
+
+ return ret;
+}
+
+static void atcspi_set_trans_ctl(struct atcspi_dev *spi,
+ const struct spi_mem_op *op)
+{
+ unsigned int tc = 0;
+
+ if (op->cmd.nbytes)
+ tc |= TRANS_CMD_EN;
+ if (op->addr.nbytes)
+ tc |= TRANS_ADDR_EN;
+ if (op->addr.buswidth > 1)
+ tc |= TRANS_ADDR_FMT;
+ if (op->data.nbytes) {
+ tc |= TRANS_DUAL_QUAD(ffs(op->data.buswidth) - 1);
+ if (op->data.dir == SPI_MEM_DATA_IN) {
+ if (op->dummy.nbytes)
+ tc |= TRANS_MODE_DMY_READ |
+ TRANS_DUMMY_CNT(op->dummy.nbytes);
+ else
+ tc |= TRANS_MODE_R_ONLY;
+ tc |= TRANS_RD_TRANS_CNT(op->data.nbytes);
+ } else {
+ tc |= TRANS_MODE_W_ONLY |
+ TRANS_WR_TRANS_CNT(op->data.nbytes);
+ }
+ } else {
+ tc |= TRANS_MODE_NONE_DATA;
+ }
+ regmap_write(spi->regmap, ATCSPI_TRANS_CTRL, tc);
+}
+
+static void atcspi_set_trans_fmt(struct atcspi_dev *spi,
+ const struct spi_mem_op *op)
+{
+ unsigned int val;
+
+ regmap_read(spi->regmap, ATCSPI_TRANS_FMT, &val);
+ if (op->data.nbytes) {
+ if (ATCSPI_DATA_MERGE_EN && ATCSPI_BITS_PER_UINT == 8 &&
+ !(op->data.nbytes % 4)) {
+ val |= TRANS_FMT_DATA_MERGE_EN;
+ spi->data_merge = true;
+ } else {
+ val &= ~TRANS_FMT_DATA_MERGE_EN;
+ spi->data_merge = false;
+ }
+ }
+
+ val = (val & ~TRANS_FMT_ADDR_LEN_MASK) |
+ TRANS_FMT_ADDR_LEN(op->addr.nbytes);
+ regmap_write(spi->regmap, ATCSPI_TRANS_FMT, val);
+}
+
+static void atcspi_prepare_trans(struct atcspi_dev *spi,
+ const struct spi_mem_op *op)
+{
+ atcspi_set_trans_fmt(spi, op);
+ atcspi_set_trans_ctl(spi, op);
+ if (op->addr.nbytes)
+ regmap_write(spi->regmap, ATCSPI_ADDR, op->addr.val);
+ regmap_write(spi->regmap, ATCSPI_CMD, op->cmd.opcode);
+}
+
+static int atcspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+ struct atcspi_dev *spi;
+
+ spi = spi_controller_get_devdata(mem->spi->controller);
+ op->data.nbytes = min(op->data.nbytes, ATCSPI_MAX_TRANS_LEN);
+
+ /* DMA needs to be aligned to 4 byte */
+ if (spi->use_dma && op->data.nbytes >= ATCSPI_DMA_THRESHOLD)
+ op->data.nbytes = ALIGN_DOWN(op->data.nbytes, 4);
+
+ return 0;
+}
+
+static int atcspi_dma_config(struct atcspi_dev *spi, bool is_rx)
+{
+ struct dma_slave_config conf = { 0 };
+ struct dma_chan *chan;
+
+ if (is_rx) {
+ chan = spi->host->dma_rx;
+ conf.direction = DMA_DEV_TO_MEM;
+ conf.src_addr = spi->dma_addr;
+ } else {
+ chan = spi->host->dma_tx;
+ conf.direction = DMA_MEM_TO_DEV;
+ conf.dst_addr = spi->dma_addr;
+ }
+ conf.dst_maxburst = spi->rxfifo_size / 2;
+ conf.src_maxburst = spi->txfifo_size / 2;
+
+ if (spi->data_merge) {
+ conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ } else {
+ conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ }
+
+ return dmaengine_slave_config(chan, &conf);
+}
+
+static void atcspi_dma_callback(void *arg)
+{
+ struct completion *dma_completion = arg;
+
+ complete(dma_completion);
+}
+
+static int atcspi_dma_trans(struct atcspi_dev *spi,
+ const struct spi_mem_op *op)
+{
+ struct dma_async_tx_descriptor *desc;
+ struct dma_chan *dma_ch;
+ struct sg_table sgt;
+ enum dma_transfer_direction dma_dir;
+ dma_cookie_t cookie;
+ unsigned int ctrl;
+ int timeout;
+ int ret;
+
+ regmap_read(spi->regmap, ATCSPI_CTRL, &ctrl);
+ ctrl |= CTRL_TX_DMA_EN | CTRL_RX_DMA_EN;
+ regmap_write(spi->regmap, ATCSPI_CTRL, ctrl);
+ if (op->data.dir == SPI_MEM_DATA_IN) {
+ ret = atcspi_dma_config(spi, TRUE);
+ dma_dir = DMA_DEV_TO_MEM;
+ dma_ch = spi->host->dma_rx;
+ } else {
+ ret = atcspi_dma_config(spi, FALSE);
+ dma_dir = DMA_MEM_TO_DEV;
+ dma_ch = spi->host->dma_tx;
+ }
+ if (ret)
+ return ret;
+
+ ret = spi_controller_dma_map_mem_op_data(spi->host, op, &sgt);
+ if (ret)
+ return ret;
+
+ desc = dmaengine_prep_slave_sg(dma_ch, sgt.sgl, sgt.nents, dma_dir,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ ret = -ENOMEM;
+ goto exit_unmap;
+ }
+
+ reinit_completion(&spi->dma_completion);
+ desc->callback = atcspi_dma_callback;
+ desc->callback_param = &spi->dma_completion;
+ cookie = dmaengine_submit(desc);
+ ret = dma_submit_error(cookie);
+ if (ret)
+ goto exit_unmap;
+
+ dma_async_issue_pending(dma_ch);
+ timeout = msecs_to_jiffies(ATCSPI_XFER_TIMEOUT(op->data.nbytes));
+ if (!wait_for_completion_timeout(&spi->dma_completion, timeout)) {
+ ret = -ETIMEDOUT;
+ dmaengine_terminate_all(dma_ch);
+ }
+
+exit_unmap:
+ spi_controller_dma_unmap_mem_op_data(spi->host, op, &sgt);
+
+ return ret;
+}
+
+static int atcspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ struct spi_device *spi_dev = mem->spi;
+ struct atcspi_dev *spi;
+ unsigned int val;
+ int ret;
+
+ spi = spi_controller_get_devdata(spi_dev->controller);
+ mutex_lock(&spi->mutex_lock);
+ atcspi_prepare_trans(spi, op);
+ if (op->data.nbytes) {
+ if (spi->use_dma && op->data.nbytes >= ATCSPI_DMA_THRESHOLD)
+ ret = atcspi_dma_trans(spi, op);
+ else
+ ret = atcspi_xfer_data_poll(spi, op);
+ if (ret) {
+ dev_info(spi->dev, "SPI transmission failed\n");
+ goto exec_mem_exit;
+ }
+ }
+
+ ret = regmap_read_poll_timeout(spi->regmap,
+ ATCSPI_STATUS,
+ val,
+ !(val & ATCSPI_ACTIVE),
+ 0,
+ ATCSPI_RDY_TIMEOUT_US);
+ if (ret)
+ dev_info(spi->dev, "Timed out waiting for ATCSPI_ACTIVE\n");
+
+exec_mem_exit:
+ mutex_unlock(&spi->mutex_lock);
+
+ return ret;
+}
+
+static const struct spi_controller_mem_ops atcspi_mem_ops = {
+ .exec_op = atcspi_exec_mem_op,
+ .adjust_op_size = atcspi_adjust_op_size,
+};
+
+static int atcspi_setup(struct atcspi_dev *spi)
+{
+ unsigned int ctrl_val;
+ unsigned int val;
+ int actual_spi_sclk_f;
+ int ret;
+ unsigned char div;
+
+ ctrl_val = CTRL_TX_FIFO_RST | CTRL_RX_FIFO_RST | CTRL_SPI_RST;
+ regmap_write(spi->regmap, ATCSPI_CTRL, ctrl_val);
+ ret = regmap_read_poll_timeout(spi->regmap,
+ ATCSPI_CTRL,
+ val,
+ !(val & ctrl_val),
+ 0,
+ ATCSPI_RDY_TIMEOUT_US);
+ if (ret)
+ return dev_err_probe(spi->dev, ret,
+ "Timed out waiting for ATCSPI_CTRL\n");
+
+ val = TRANS_FMT_DATA_LEN(ATCSPI_BITS_PER_UINT) |
+ TRANS_FMT_CPHA | TRANS_FMT_CPOL;
+ regmap_write(spi->regmap, ATCSPI_TRANS_FMT, val);
+
+ regmap_read(spi->regmap, ATCSPI_CONFIG, &val);
+ spi->txfifo_size = BIT(TXFIFO_SIZE(val) + 1);
+ spi->rxfifo_size = BIT(RXFIFO_SIZE(val) + 1);
+
+ regmap_read(spi->regmap, ATCSPI_TIMING, &val);
+ val &= ~TIMING_SCLK_DIV_MASK;
+
+ /*
+ * The SCLK_DIV value 0xFF is special and indicates that the
+ * SCLK rate should be the same as the SPI clock rate.
+ */
+ if (spi->sclk_rate >= spi->clk_rate) {
+ div = TIMING_SCLK_DIV_MASK;
+ } else {
+ /*
+ * The divider value is determined as follows:
+ * 1. If the divider can generate the exact target frequency,
+ * use that setting.
+ * 2. If an exact match is not possible, select the closest
+ * available setting that is lower than the target frequency.
+ */
+ div = (spi->clk_rate + (spi->sclk_rate * 2 - 1)) /
+ (spi->sclk_rate * 2) - 1;
+
+ /* Check if the actual SPI clock is lower than the target */
+ actual_spi_sclk_f = spi->clk_rate / ((div + 1) * 2);
+ if (actual_spi_sclk_f < spi->sclk_rate)
+ dev_info(spi->dev,
+ "Clock adjusted %d to %d due to divider limitation",
+ spi->sclk_rate, actual_spi_sclk_f);
+
+ if (div > TIMING_SCLK_DIV_MAX)
+ return dev_err_probe(spi->dev, -EINVAL,
+ "Unsupported SPI clock %d\n",
+ spi->sclk_rate);
+ }
+ val |= div;
+ regmap_write(spi->regmap, ATCSPI_TIMING, val);
+
+ return ret;
+}
+
+static int atcspi_init_resources(struct platform_device *pdev,
+ struct atcspi_dev *spi,
+ struct resource **mem_res)
+{
+ void __iomem *base;
+ const struct regmap_config atcspi_regmap_cfg = {
+ .name = "atcspi",
+ .reg_bits = 32,
+ .val_bits = 32,
+ .cache_type = REGCACHE_NONE,
+ .reg_stride = 4,
+ .pad_bits = 0,
+ .max_register = ATCSPI_CONFIG
+ };
+
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, mem_res);
+ if (IS_ERR(base))
+ return dev_err_probe(spi->dev, PTR_ERR(base),
+ "Failed to get ioremap resource\n");
+
+ spi->regmap = devm_regmap_init_mmio(spi->dev, base,
+ &atcspi_regmap_cfg);
+ if (IS_ERR(spi->regmap))
+ return dev_err_probe(spi->dev, PTR_ERR(spi->regmap),
+ "Failed to init regmap\n");
+
+ spi->clk = devm_clk_get(spi->dev, NULL);
+ if (IS_ERR(spi->clk))
+ return dev_err_probe(spi->dev, PTR_ERR(spi->clk),
+ "Failed to get SPI clock\n");
+
+ spi->sclk_rate = ATCSPI_MAX_SPEED_HZ;
+ return 0;
+}
+
+static struct dma_chan *atcspi_request_dma_chan(struct device *dev,
+ unsigned char *chan_name)
+{
+ struct dma_chan *dma_chan;
+ dma_cap_mask_t mask;
+
+ dma_chan = dma_request_chan(dev, chan_name);
+ if (PTR_ERR(dma_chan) == -ENODEV) {
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ dma_chan = dma_request_channel(mask, NULL, NULL);
+ }
+
+ return dma_chan;
+}
+
+static int atcspi_configure_dma(struct atcspi_dev *spi)
+{
+ struct dma_chan *dma_chan;
+ int ret = 0;
+
+ dma_chan = atcspi_request_dma_chan(spi->dev, "spi_rx");
+ if (IS_ERR(dma_chan)) {
+ ret = PTR_ERR(dma_chan);
+ goto err_exit;
+ }
+ spi->host->dma_rx = dma_chan;
+
+ dma_chan = atcspi_request_dma_chan(spi->dev, "spi_tx");
+ if (IS_ERR(dma_chan)) {
+ ret = PTR_ERR(dma_chan);
+ goto free_rx;
+ }
+ spi->host->dma_tx = dma_chan;
+ init_completion(&spi->dma_completion);
+
+ return ret;
+
+free_rx:
+ dma_release_channel(spi->host->dma_rx);
+ spi->host->dma_rx = NULL;
+err_exit:
+ return ret;
+}
+
+static int atcspi_enable_clk(struct atcspi_dev *spi)
+{
+ int ret;
+
+ ret = clk_prepare_enable(spi->clk);
+ if (ret)
+ return dev_err_probe(spi->dev, ret,
+ "Failed to enable clock\n");
+
+ spi->clk_rate = clk_get_rate(spi->clk);
+ if (!spi->clk_rate)
+ return dev_err_probe(spi->dev, -EINVAL,
+ "Failed to get SPI clock rate\n");
+
+ return 0;
+}
+
+static void atcspi_init_controller(struct platform_device *pdev,
+ struct atcspi_dev *spi,
+ struct spi_controller *host,
+ struct resource *mem_res)
+{
+ /* Get the physical address of the data register for DMA transfers. */
+ spi->dma_addr = (dma_addr_t)(mem_res->start + ATCSPI_DATA);
+
+ /* Initialize controller properties */
+ host->bus_num = pdev->id;
+ host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_QUAD | SPI_TX_QUAD;
+ host->dev.of_node = pdev->dev.of_node;
+ host->num_chipselect = ATCSPI_MAX_CS_NUM;
+ host->mem_ops = &atcspi_mem_ops;
+ host->max_speed_hz = spi->sclk_rate;
+}
+
+static int atcspi_probe(struct platform_device *pdev)
+{
+ struct spi_controller *host;
+ struct atcspi_dev *spi;
+ struct resource *mem_res;
+ int ret;
+
+ host = spi_alloc_host(&pdev->dev, sizeof(*spi));
+ if (!host)
+ return -ENOMEM;
+
+ spi = spi_controller_get_devdata(host);
+ spi->host = host;
+ spi->dev = &pdev->dev;
+ platform_set_drvdata(pdev, host);
+
+ ret = atcspi_init_resources(pdev, spi, &mem_res);
+ if (ret)
+ goto free_controller;
+
+ ret = atcspi_enable_clk(spi);
+ if (ret)
+ goto free_controller;
+
+ atcspi_init_controller(pdev, spi, host, mem_res);
+
+ ret = atcspi_setup(spi);
+ if (ret)
+ goto free_controller;
+
+ ret = devm_spi_register_controller(&pdev->dev, host);
+ if (ret) {
+ dev_err_probe(spi->dev, ret,
+ "Failed to register SPI controller\n");
+ goto free_controller;
+ }
+
+ spi->use_dma = false;
+ if (ATCSPI_DMA_SUPPORT) {
+ ret = atcspi_configure_dma(spi);
+ if (ret)
+ dev_info(spi->dev,
+ "Failed to init DMA, fallback to PIO mode\n");
+ else
+ spi->use_dma = true;
+ }
+ mutex_init(&spi->mutex_lock);
+
+ return 0;
+
+free_controller:
+ spi_controller_put(host);
+ return ret;
+}
+
+static const struct of_device_id atcspi_of_match[] = {
+ { .compatible = "andestech,qilai-spi", },
+ { .compatible = "andestech,atcspi200", },
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, atcspi_of_match);
+
+static struct platform_driver atcspi_driver = {
+ .probe = atcspi_probe,
+ .driver = {
+ .name = "atcspi200",
+ .of_match_table = atcspi_of_match,
+ },
+};
+module_platform_driver(atcspi_driver);
+
+MODULE_AUTHOR("CL Wang <cl634@andestech.com>");
+MODULE_DESCRIPTION("Andes ATCSPI200 SPI controller driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread