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Subject[PATCH] spi: spi-geni-qcom: Add SPI driver support for GENI based QUP
Date
This driver supports GENI based SPI Controller in the Qualcomm SOCs. The
Qualcomm Generic Interface (GENI) is a programmable module supporting a
wide range of serial interfaces including SPI. This driver supports SPI
operations using FIFO mode of transfer.

Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
---
drivers/spi/Kconfig | 12 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-geni-qcom.c | 766 ++++++++++++++++++++++++++++++++++++++
include/linux/spi/spi-geni-qcom.h | 14 +
4 files changed, 793 insertions(+)
create mode 100644 drivers/spi/spi-geni-qcom.c
create mode 100644 include/linux/spi/spi-geni-qcom.h

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 9b31351..358d60a 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -564,6 +564,18 @@ config SPI_QUP
This driver can also be built as a module. If so, the module
will be called spi_qup.

+config SPI_QCOM_GENI
+ tristate "Qualcomm SPI controller with QUP interface"
+ depends on ARCH_QCOM || (ARM && COMPILE_TEST)
+ help
+ This driver supports GENI serial engine based SPI controller in
+ master mode on the Qualcomm Technologies Inc.'s SoCs. If you say
+ yes to this option, support will be included for the built-in SPI
+ interface on the Qualcomm Technologies Inc.'s SoCs.
+
+ This driver can also be built as a module. If so, the module
+ will be called spi-geni-qcom.
+
config SPI_S3C24XX
tristate "Samsung S3C24XX series SPI"
depends on ARCH_S3C24XX
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index a3ae2b7..cc90d6e 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -77,6 +77,7 @@ spi-pxa2xx-platform-objs := spi-pxa2xx.o spi-pxa2xx-dma.o
obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx-platform.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o
obj-$(CONFIG_SPI_QUP) += spi-qup.o
+obj-$(CONFIG_SPI_QCOM_GENI) += spi-geni-qcom.o
obj-$(CONFIG_SPI_ROCKCHIP) += spi-rockchip.o
obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o
obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
new file mode 100644
index 0000000..eecc634
--- /dev/null
+++ b/drivers/spi/spi-geni-qcom.c
@@ -0,0 +1,766 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/spinlock.h>
+#include <linux/qcom-geni-se.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-geni-qcom.h>
+
+#define SPI_NUM_CHIPSELECT 4
+#define SPI_XFER_TIMEOUT_MS 250
+/* SPI SE specific registers */
+#define SE_SPI_CPHA 0x224
+#define SE_SPI_LOOPBACK 0x22c
+#define SE_SPI_CPOL 0x230
+#define SE_SPI_DEMUX_OUTPUT_INV 0x24c
+#define SE_SPI_DEMUX_SEL 0x250
+#define SE_SPI_TRANS_CFG 0x25c
+#define SE_SPI_WORD_LEN 0x268
+#define SE_SPI_TX_TRANS_LEN 0x26c
+#define SE_SPI_RX_TRANS_LEN 0x270
+#define SE_SPI_PRE_POST_CMD_DLY 0x274
+#define SE_SPI_DELAY_COUNTERS 0x278
+
+/* SE_SPI_CPHA register fields */
+#define CPHA BIT(0)
+
+/* SE_SPI_LOOPBACK register fields */
+#define LOOPBACK_ENABLE 0x1
+#define NORMAL_MODE 0x0
+#define LOOPBACK_MSK GENMASK(1, 0)
+
+/* SE_SPI_CPOL register fields */
+#define CPOL BIT(2)
+
+/* SE_SPI_DEMUX_OUTPUT_INV register fields */
+#define CS_DEMUX_OUTPUT_INV_MSK GENMASK(3, 0)
+
+/* SE_SPI_DEMUX_SEL register fields */
+#define CS_DEMUX_OUTPUT_SEL GENMASK(3, 0)
+
+/* SE_SPI_TX_TRANS_CFG register fields */
+#define CS_TOGGLE BIT(0)
+
+/* SE_SPI_WORD_LEN register fields */
+#define WORD_LEN_MSK GENMASK(9, 0)
+#define MIN_WORD_LEN 4
+
+/* SPI_TX/SPI_RX_TRANS_LEN fields */
+#define TRANS_LEN_MSK GENMASK(23, 0)
+
+/* SE_SPI_DELAY_COUNTERS */
+#define SPI_INTER_WORDS_DELAY_MSK GENMASK(9, 0)
+#define SPI_CS_CLK_DELAY_MSK GENMASK(19, 10)
+#define SPI_CS_CLK_DELAY_SHFT 10
+
+/* M_CMD OP codes for SPI */
+#define SPI_TX_ONLY 1
+#define SPI_RX_ONLY 2
+#define SPI_FULL_DUPLEX 3
+#define SPI_TX_RX 7
+#define SPI_CS_ASSERT 8
+#define SPI_CS_DEASSERT 9
+#define SPI_SCK_ONLY 10
+/* M_CMD params for SPI */
+#define SPI_PRE_CMD_DELAY BIT(0)
+#define TIMESTAMP_BEFORE BIT(1)
+#define FRAGMENTATION BIT(2)
+#define TIMESTAMP_AFTER BIT(3)
+#define POST_CMD_DELAY BIT(4)
+
+static irqreturn_t geni_spi_isr(int irq, void *dev);
+
+struct spi_geni_master {
+ struct geni_se se;
+ int irq;
+ struct device *dev;
+ int rx_fifo_depth;
+ int tx_fifo_depth;
+ int tx_fifo_width;
+ int tx_wm;
+ bool setup;
+ u32 cur_speed_hz;
+ int cur_word_len;
+ spinlock_t lock;
+ unsigned int tx_rem_bytes;
+ unsigned int rx_rem_bytes;
+ struct spi_transfer *cur_xfer;
+ struct completion xfer_done;
+ int oversampling;
+};
+
+static struct spi_master *get_spi_master(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct spi_master *spi = platform_get_drvdata(pdev);
+
+ return spi;
+}
+
+static int get_spi_clk_cfg(u32 speed_hz, struct spi_geni_master *mas,
+ int *clk_idx, int *clk_div)
+{
+ unsigned long sclk_freq;
+ struct geni_se *se = &mas->se;
+ int ret;
+
+ ret = geni_se_clk_freq_match(&mas->se,
+ (speed_hz * mas->oversampling), clk_idx,
+ &sclk_freq, true);
+ if (ret) {
+ dev_err(mas->dev, "%s: Failed(%d) to find src clk for 0x%x\n",
+ __func__, ret, speed_hz);
+ return ret;
+ }
+
+ *clk_div = ((sclk_freq / mas->oversampling) / speed_hz);
+ if (!(*clk_div)) {
+ dev_err(mas->dev, "%s:Err:sclk:%lu oversampling:%d speed:%u\n",
+ __func__, sclk_freq, mas->oversampling, speed_hz);
+ return -EINVAL;
+ }
+
+ dev_dbg(mas->dev, "%s: req %u sclk %lu, idx %d, div %d\n", __func__,
+ speed_hz, sclk_freq, *clk_idx, *clk_div);
+ ret = clk_set_rate(se->clk, sclk_freq);
+ if (ret)
+ dev_err(mas->dev, "%s: clk_set_rate failed %d\n",
+ __func__, ret);
+ return ret;
+}
+
+static void spi_setup_word_len(struct spi_geni_master *mas, u32 mode,
+ int bits_per_word)
+{
+ int pack_words = 1;
+ bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
+ struct geni_se *se = &mas->se;
+ u32 word_len;
+
+ word_len = readl_relaxed(se->base + SE_SPI_WORD_LEN);
+
+ /*
+ * If bits_per_word isn't a byte aligned value, set the packing to be
+ * 1 SPI word per FIFO word.
+ */
+ if (!(mas->tx_fifo_width % bits_per_word))
+ pack_words = mas->tx_fifo_width / bits_per_word;
+ word_len &= ~WORD_LEN_MSK;
+ word_len |= ((bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK);
+ geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
+ true, true);
+ writel_relaxed(word_len, se->base + SE_SPI_WORD_LEN);
+}
+
+static int setup_fifo_params(struct spi_device *spi_slv,
+ struct spi_master *spi)
+{
+ struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ struct geni_se *se = &mas->se;
+ u16 mode = spi_slv->mode;
+ u32 loopback_cfg = readl_relaxed(se->base + SE_SPI_LOOPBACK);
+ u32 cpol = readl_relaxed(se->base + SE_SPI_CPOL);
+ u32 cpha = readl_relaxed(se->base + SE_SPI_CPHA);
+ u32 demux_sel = 0;
+ u32 demux_output_inv = 0;
+ u32 clk_sel = 0;
+ u32 m_clk_cfg = 0;
+ int ret = 0;
+ int idx;
+ int div;
+ struct spi_geni_qcom_ctrl_data *delay_params = NULL;
+ u32 spi_delay_params = 0;
+
+ loopback_cfg &= ~LOOPBACK_MSK;
+ cpol &= ~CPOL;
+ cpha &= ~CPHA;
+
+ if (mode & SPI_LOOP)
+ loopback_cfg |= LOOPBACK_ENABLE;
+
+ if (mode & SPI_CPOL)
+ cpol |= CPOL;
+
+ if (mode & SPI_CPHA)
+ cpha |= CPHA;
+
+ if (spi_slv->mode & SPI_CS_HIGH)
+ demux_output_inv |= BIT(spi_slv->chip_select);
+
+ if (spi_slv->controller_data) {
+ u32 cs_clk_delay = 0;
+ u32 inter_words_delay = 0;
+
+ delay_params =
+ (struct spi_geni_qcom_ctrl_data *) spi_slv->controller_data;
+ cs_clk_delay =
+ (delay_params->spi_cs_clk_delay << SPI_CS_CLK_DELAY_SHFT)
+ & SPI_CS_CLK_DELAY_MSK;
+ inter_words_delay =
+ delay_params->spi_inter_words_delay &
+ SPI_INTER_WORDS_DELAY_MSK;
+ spi_delay_params =
+ (inter_words_delay | cs_clk_delay);
+ }
+
+ demux_sel = spi_slv->chip_select;
+ mas->cur_speed_hz = spi_slv->max_speed_hz;
+ mas->cur_word_len = spi_slv->bits_per_word;
+
+ ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, &idx, &div);
+ if (ret) {
+ dev_err(mas->dev, "Err setting clks ret(%d) for %d\n",
+ ret, mas->cur_speed_hz);
+ goto setup_fifo_params_exit;
+ }
+
+ clk_sel |= (idx & CLK_SEL_MSK);
+ m_clk_cfg |= ((div << CLK_DIV_SHFT) | SER_CLK_EN);
+ spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
+ writel_relaxed(loopback_cfg, se->base + SE_SPI_LOOPBACK);
+ writel_relaxed(demux_sel, se->base + SE_SPI_DEMUX_SEL);
+ writel_relaxed(cpha, se->base + SE_SPI_CPHA);
+ writel_relaxed(cpol, se->base + SE_SPI_CPOL);
+ writel_relaxed(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
+ writel_relaxed(clk_sel, se->base + SE_GENI_CLK_SEL);
+ writel_relaxed(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
+ writel_relaxed(spi_delay_params, se->base + SE_SPI_DELAY_COUNTERS);
+setup_fifo_params_exit:
+ return ret;
+}
+
+static int spi_geni_prepare_message(struct spi_master *spi,
+ struct spi_message *spi_msg)
+{
+ int ret = 0;
+ struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ struct geni_se *se = &mas->se;
+
+ geni_se_select_mode(se, GENI_SE_FIFO);
+ reinit_completion(&mas->xfer_done);
+ ret = setup_fifo_params(spi_msg->spi, spi);
+ if (ret) {
+ dev_err(mas->dev, "%s: Couldn't select mode %d", __func__, ret);
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
+static int spi_geni_unprepare_message(struct spi_master *spi_mas,
+ struct spi_message *spi_msg)
+{
+ struct spi_geni_master *mas = spi_master_get_devdata(spi_mas);
+
+ mas->cur_speed_hz = 0;
+ mas->cur_word_len = 0;
+ return 0;
+}
+
+static int spi_geni_prepare_transfer_hardware(struct spi_master *spi)
+{
+ struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ int ret = 0;
+ struct geni_se *se = &mas->se;
+
+ ret = pm_runtime_get_sync(mas->dev);
+ if (ret < 0) {
+ dev_err(mas->dev, "Error enabling SE resources\n");
+ pm_runtime_put_noidle(mas->dev);
+ goto exit_prepare_transfer_hardware;
+ } else {
+ ret = 0;
+ }
+
+ if (unlikely(!mas->setup)) {
+ int proto = geni_se_read_proto(se);
+ unsigned int major;
+ unsigned int minor;
+ unsigned int step;
+
+ if (unlikely(proto != GENI_SE_SPI)) {
+ dev_err(mas->dev, "Invalid proto %d\n", proto);
+ return -ENXIO;
+ }
+ mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
+ mas->rx_fifo_depth = geni_se_get_rx_fifo_depth(se);
+ mas->tx_fifo_width = geni_se_get_tx_fifo_width(se);
+ geni_se_init(se, 0x0, (mas->tx_fifo_depth - 2));
+ mas->oversampling = 1;
+ /* Transmit an entire FIFO worth of data per IRQ */
+ mas->tx_wm = 1;
+ geni_se_get_wrapper_version(se, major, minor, step);
+ if ((major == 1) && (minor == 0))
+ mas->oversampling = 2;
+ mas->setup = 1;
+ ret = devm_request_irq(mas->dev, mas->irq, geni_spi_isr,
+ IRQF_TRIGGER_HIGH, "spi_geni", mas);
+ if (ret) {
+ dev_err(mas->dev, "Request_irq failed:%d: err:%d\n",
+ mas->irq, ret);
+ goto exit_prepare_transfer_hardware;
+ }
+ }
+exit_prepare_transfer_hardware:
+ return ret;
+}
+
+static int spi_geni_unprepare_transfer_hardware(struct spi_master *spi)
+{
+ struct spi_geni_master *mas = spi_master_get_devdata(spi);
+
+ pm_runtime_put_sync(mas->dev);
+ return 0;
+}
+
+static void setup_fifo_xfer(struct spi_transfer *xfer,
+ struct spi_geni_master *mas, u16 mode,
+ struct spi_master *spi)
+{
+ u32 m_cmd = 0;
+ u32 m_param = 0;
+ struct geni_se *se = &mas->se;
+ u32 spi_tx_cfg = readl_relaxed(se->base + SE_SPI_TRANS_CFG);
+ u32 trans_len = 0;
+
+ if (xfer->bits_per_word != mas->cur_word_len) {
+ spi_setup_word_len(mas, mode, xfer->bits_per_word);
+ mas->cur_word_len = xfer->bits_per_word;
+ }
+
+ /* Speed and bits per word can be overridden per transfer */
+ if (xfer->speed_hz != mas->cur_speed_hz) {
+ int ret = 0;
+ u32 clk_sel = 0;
+ u32 m_clk_cfg = 0;
+ int idx = 0;
+ int div = 0;
+
+ ret = get_spi_clk_cfg(xfer->speed_hz, mas, &idx, &div);
+ if (ret) {
+ dev_err(mas->dev, "%s:Err setting clks:%d\n",
+ __func__, ret);
+ return;
+ }
+ mas->cur_speed_hz = xfer->speed_hz;
+ clk_sel |= (idx & CLK_SEL_MSK);
+ m_clk_cfg |= ((div << CLK_DIV_SHFT) | SER_CLK_EN);
+ writel_relaxed(clk_sel, se->base + SE_GENI_CLK_SEL);
+ writel_relaxed(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
+ }
+
+ mas->tx_rem_bytes = 0;
+ mas->rx_rem_bytes = 0;
+ if (xfer->tx_buf && xfer->rx_buf)
+ m_cmd = SPI_FULL_DUPLEX;
+ else if (xfer->tx_buf)
+ m_cmd = SPI_TX_ONLY;
+ else if (xfer->rx_buf)
+ m_cmd = SPI_RX_ONLY;
+
+ spi_tx_cfg &= ~CS_TOGGLE;
+ if (!(mas->cur_word_len % MIN_WORD_LEN)) {
+ trans_len =
+ ((xfer->len * BITS_PER_BYTE) /
+ mas->cur_word_len) & TRANS_LEN_MSK;
+ } else {
+ int bytes_per_word = (mas->cur_word_len / BITS_PER_BYTE) + 1;
+
+ trans_len = (xfer->len / bytes_per_word) & TRANS_LEN_MSK;
+ }
+
+ /*
+ * If CS change flag is set, then toggle the CS line in between
+ * transfers and keep CS asserted after the last transfer.
+ * Else if keep CS flag asserted in between transfers and de-assert
+ * CS after the last message.
+ */
+ if (xfer->cs_change) {
+ if (list_is_last(&xfer->transfer_list,
+ &spi->cur_msg->transfers))
+ m_param |= FRAGMENTATION;
+ } else {
+ if (!list_is_last(&xfer->transfer_list,
+ &spi->cur_msg->transfers))
+ m_param |= FRAGMENTATION;
+ }
+
+ mas->cur_xfer = xfer;
+ if (m_cmd & SPI_TX_ONLY) {
+ mas->tx_rem_bytes = xfer->len;
+ writel_relaxed(trans_len, se->base + SE_SPI_TX_TRANS_LEN);
+ }
+
+ if (m_cmd & SPI_RX_ONLY) {
+ writel_relaxed(trans_len, se->base + SE_SPI_RX_TRANS_LEN);
+ mas->rx_rem_bytes = xfer->len;
+ }
+ writel_relaxed(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
+ geni_se_setup_m_cmd(se, m_cmd, m_param);
+ if (m_cmd & SPI_TX_ONLY)
+ writel_relaxed(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
+}
+
+static void handle_fifo_timeout(struct spi_geni_master *mas)
+{
+ unsigned long timeout;
+ struct geni_se *se = &mas->se;
+ unsigned long flags;
+
+ reinit_completion(&mas->xfer_done);
+ spin_lock_irqsave(&mas->lock, flags);
+ geni_se_cancel_m_cmd(se);
+ writel_relaxed(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ timeout = wait_for_completion_timeout(&mas->xfer_done, HZ);
+ if (!timeout) {
+ reinit_completion(&mas->xfer_done);
+ geni_se_abort_m_cmd(se);
+ timeout = wait_for_completion_timeout(&mas->xfer_done,
+ HZ);
+ if (!timeout)
+ dev_err(mas->dev,
+ "Failed to cancel/abort m_cmd\n");
+ }
+ spin_unlock_irqrestore(&mas->lock, flags);
+}
+
+static int spi_geni_transfer_one(struct spi_master *spi,
+ struct spi_device *slv,
+ struct spi_transfer *xfer)
+{
+ int ret = 0;
+ struct spi_geni_master *mas = spi_master_get_devdata(spi);
+ unsigned long timeout;
+
+ if ((xfer->tx_buf == NULL) && (xfer->rx_buf == NULL)) {
+ dev_err(mas->dev, "Invalid xfer both tx rx are NULL\n");
+ return -EINVAL;
+ }
+
+ setup_fifo_xfer(xfer, mas, slv->mode, spi);
+ timeout = wait_for_completion_timeout(&mas->xfer_done,
+ msecs_to_jiffies(SPI_XFER_TIMEOUT_MS));
+ if (!timeout) {
+ dev_err(mas->dev,
+ "Xfer[len %d tx %pK rx %pK n %d] timed out.\n",
+ xfer->len, xfer->tx_buf,
+ xfer->rx_buf,
+ xfer->bits_per_word);
+ mas->cur_xfer = NULL;
+ ret = -ETIMEDOUT;
+ goto err_fifo_geni_transfer_one;
+ }
+ return ret;
+err_fifo_geni_transfer_one:
+ handle_fifo_timeout(mas);
+ return ret;
+}
+
+static void geni_spi_handle_tx(struct spi_geni_master *mas)
+{
+ int i = 0;
+ int tx_fifo_width = mas->tx_fifo_width / BITS_PER_BYTE;
+ int max_bytes = 0;
+ const u8 *tx_buf;
+ struct geni_se *se = &mas->se;
+
+ if (!mas->cur_xfer)
+ return;
+
+ /*
+ * For non-byte aligned bits-per-word values. (e.g 9)
+ * The FIFO packing is set to 1 SPI word per FIFO word.
+ * Assumption is that each SPI word will be accomodated in
+ * ceil (bits_per_word / bits_per_byte)
+ * and the next SPI word starts at the next byte.
+ * In such cases, we can fit 1 SPI word per FIFO word so adjust the
+ * max byte that can be sent per IRQ accordingly.
+ */
+ if ((mas->tx_fifo_width % mas->cur_word_len))
+ max_bytes = (mas->tx_fifo_depth - mas->tx_wm) *
+ ((mas->cur_word_len / BITS_PER_BYTE) + 1);
+ else
+ max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * tx_fifo_width;
+ tx_buf = mas->cur_xfer->tx_buf;
+ tx_buf += (mas->cur_xfer->len - mas->tx_rem_bytes);
+ max_bytes = min_t(int, mas->tx_rem_bytes, max_bytes);
+ while (i < max_bytes) {
+ int j;
+ u32 fifo_word = 0;
+ u8 *fifo_byte;
+ int bytes_per_fifo = tx_fifo_width;
+ int bytes_to_write = 0;
+
+ if ((mas->tx_fifo_width % mas->cur_word_len))
+ bytes_per_fifo =
+ (mas->cur_word_len / BITS_PER_BYTE) + 1;
+ bytes_to_write = min_t(int, max_bytes - i, bytes_per_fifo);
+ fifo_byte = (u8 *)&fifo_word;
+ for (j = 0; j < bytes_to_write; j++)
+ fifo_byte[j] = tx_buf[i++];
+ iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
+ }
+ mas->tx_rem_bytes -= max_bytes;
+ if (!mas->tx_rem_bytes)
+ writel_relaxed(0, se->base + SE_GENI_TX_WATERMARK_REG);
+}
+
+static void geni_spi_handle_rx(struct spi_geni_master *mas)
+{
+ int i = 0;
+ struct geni_se *se = &mas->se;
+ int fifo_width = mas->tx_fifo_width / BITS_PER_BYTE;
+ u32 rx_fifo_status = readl_relaxed(se->base + SE_GENI_RX_FIFO_STATUS);
+ int rx_bytes = 0;
+ int rx_wc = 0;
+ u8 *rx_buf;
+
+ if (!mas->cur_xfer)
+ return;
+
+ rx_buf = mas->cur_xfer->rx_buf;
+ rx_wc = rx_fifo_status & RX_FIFO_WC_MSK;
+ if (rx_fifo_status & RX_LAST) {
+ int rx_last_byte_valid =
+ (rx_fifo_status & RX_LAST_BYTE_VALID_MSK)
+ >> RX_LAST_BYTE_VALID_SHFT;
+ if (rx_last_byte_valid && (rx_last_byte_valid < 4)) {
+ rx_wc -= 1;
+ rx_bytes += rx_last_byte_valid;
+ }
+ }
+
+ /*
+ * For non-byte aligned bits-per-word values. (e.g 9)
+ * The FIFO packing is set to 1 SPI word per FIFO word.
+ * Assumption is that each SPI word will be accomodated in
+ * ceil (bits_per_word / bits_per_byte)
+ * and the next SPI word starts at the next byte.
+ */
+ if (!(mas->tx_fifo_width % mas->cur_word_len))
+ rx_bytes += rx_wc * fifo_width;
+ else
+ rx_bytes += rx_wc *
+ ((mas->cur_word_len / BITS_PER_BYTE) + 1);
+ rx_bytes = min_t(int, mas->rx_rem_bytes, rx_bytes);
+ rx_buf += (mas->cur_xfer->len - mas->rx_rem_bytes);
+ while (i < rx_bytes) {
+ u32 fifo_word = 0;
+ u8 *fifo_byte;
+ int bytes_per_fifo = fifo_width;
+ int read_bytes = 0;
+ int j;
+
+ if ((mas->tx_fifo_width % mas->cur_word_len))
+ bytes_per_fifo =
+ (mas->cur_word_len / BITS_PER_BYTE) + 1;
+ read_bytes = min_t(int, rx_bytes - i, bytes_per_fifo);
+ ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
+ fifo_byte = (u8 *)&fifo_word;
+ for (j = 0; j < read_bytes; j++)
+ rx_buf[i++] = fifo_byte[j];
+ }
+ mas->rx_rem_bytes -= rx_bytes;
+}
+
+static irqreturn_t geni_spi_isr(int irq, void *dev)
+{
+ struct spi_geni_master *mas = dev;
+ struct geni_se *se = &mas->se;
+ u32 m_irq = 0;
+ irqreturn_t ret = IRQ_HANDLED;
+ unsigned long flags;
+
+ spin_lock_irqsave(&mas->lock, flags);
+ if (pm_runtime_status_suspended(dev)) {
+ ret = IRQ_NONE;
+ goto exit_geni_spi_irq;
+ }
+ m_irq = readl_relaxed(se->base + SE_GENI_M_IRQ_STATUS);
+ if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
+ geni_spi_handle_rx(mas);
+
+ if ((m_irq & M_TX_FIFO_WATERMARK_EN))
+ geni_spi_handle_tx(mas);
+
+ if ((m_irq & M_CMD_DONE_EN) || (m_irq & M_CMD_CANCEL_EN) ||
+ (m_irq & M_CMD_ABORT_EN)) {
+ complete(&mas->xfer_done);
+ /*
+ * If this happens, then a CMD_DONE came before all the Tx
+ * buffer bytes were sent out. This is unusual, log this
+ * condition and disable the WM interrupt to prevent the
+ * system from stalling due an interrupt storm.
+ * If this happens when all Rx bytes haven't been received, log
+ * the condition.
+ * The only known time this can happen is if bits_per_word != 8
+ * and some registers that expect xfer lengths in num spi_words
+ * weren't written correctly.
+ */
+ if (mas->tx_rem_bytes) {
+ writel_relaxed(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ dev_err(mas->dev,
+ "%s:Premature Done.tx_rem%d bpw%d\n",
+ __func__, mas->tx_rem_bytes, mas->cur_word_len);
+ }
+ if (mas->rx_rem_bytes)
+ dev_err(mas->dev,
+ "%s:Premature Done.rx_rem%d bpw%d\n",
+ __func__, mas->rx_rem_bytes, mas->cur_word_len);
+ }
+exit_geni_spi_irq:
+ writel_relaxed(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
+ spin_unlock_irqrestore(&mas->lock, flags);
+ return ret;
+}
+
+static int spi_geni_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct spi_master *spi;
+ struct spi_geni_master *spi_geni;
+ struct resource *res;
+ struct geni_se *se;
+
+ spi = spi_alloc_master(&pdev->dev, sizeof(struct spi_geni_master));
+ if (!spi) {
+ ret = -ENOMEM;
+ dev_err(&pdev->dev, "Failed to alloc spi struct\n");
+ goto spi_geni_probe_err;
+ }
+
+ platform_set_drvdata(pdev, spi);
+ spi_geni = spi_master_get_devdata(spi);
+ spi_geni->dev = &pdev->dev;
+ spi_geni->se.dev = &pdev->dev;
+ spi_geni->se.wrapper = dev_get_drvdata(pdev->dev.parent);
+ se = &spi_geni->se;
+
+ spi->bus_num = of_alias_get_id(pdev->dev.of_node, "spi");
+ spi->dev.of_node = pdev->dev.of_node;
+ spi_geni->se.clk = devm_clk_get(&pdev->dev, "se");
+ if (IS_ERR(spi_geni->se.clk)) {
+ ret = PTR_ERR(spi_geni->se.clk);
+ dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+ goto spi_geni_probe_err;
+ }
+
+ if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
+ &spi->max_speed_hz)) {
+ dev_err(&pdev->dev, "Max frequency not specified.\n");
+ ret = -ENXIO;
+ goto spi_geni_probe_err;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ se->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(se->base)) {
+ ret = -ENOMEM;
+ dev_err(&pdev->dev, "Err IO mapping iomem\n");
+ goto spi_geni_probe_err;
+ }
+
+ spi_geni->irq = platform_get_irq(pdev, 0);
+ if (spi_geni->irq < 0) {
+ dev_err(&pdev->dev, "Err getting IRQ\n");
+ ret = spi_geni->irq;
+ goto spi_geni_probe_unmap;
+ }
+
+ spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
+ spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+ spi->num_chipselect = SPI_NUM_CHIPSELECT;
+ spi->prepare_transfer_hardware = spi_geni_prepare_transfer_hardware;
+ spi->prepare_message = spi_geni_prepare_message;
+ spi->unprepare_message = spi_geni_unprepare_message;
+ spi->transfer_one = spi_geni_transfer_one;
+ spi->unprepare_transfer_hardware
+ = spi_geni_unprepare_transfer_hardware;
+ spi->auto_runtime_pm = false;
+
+ init_completion(&spi_geni->xfer_done);
+ spin_lock_init(&spi_geni->lock);
+ pm_runtime_enable(&pdev->dev);
+ ret = spi_register_master(spi);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register SPI master\n");
+ goto spi_geni_probe_unmap;
+ }
+ dev_dbg(&pdev->dev, "%s Probed\n", __func__);
+ return ret;
+spi_geni_probe_unmap:
+ devm_iounmap(&pdev->dev, se->base);
+spi_geni_probe_err:
+ spi_master_put(spi);
+ return ret;
+}
+
+static int spi_geni_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct spi_geni_master *spi_geni = spi_master_get_devdata(master);
+
+ spi_unregister_master(master);
+ geni_se_resources_off(&spi_geni->se);
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ return 0;
+}
+
+static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
+{
+ int ret;
+ struct spi_master *spi = get_spi_master(dev);
+ struct spi_geni_master *spi_geni = spi_master_get_devdata(spi);
+
+ ret = geni_se_resources_off(&spi_geni->se);
+ return ret;
+}
+
+static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
+{
+ int ret;
+ struct spi_master *spi = get_spi_master(dev);
+ struct spi_geni_master *spi_geni = spi_master_get_devdata(spi);
+
+ ret = geni_se_resources_on(&spi_geni->se);
+ return ret;
+}
+
+static int __maybe_unused spi_geni_suspend(struct device *dev)
+{
+ if (!pm_runtime_status_suspended(dev))
+ return -EBUSY;
+ return 0;
+}
+
+static const struct dev_pm_ops spi_geni_pm_ops = {
+ SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
+ spi_geni_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, NULL)
+};
+
+static const struct of_device_id spi_geni_dt_match[] = {
+ { .compatible = "qcom,geni-spi" },
+ {}
+};
+
+static struct platform_driver spi_geni_driver = {
+ .probe = spi_geni_probe,
+ .remove = spi_geni_remove,
+ .driver = {
+ .name = "geni_spi",
+ .pm = &spi_geni_pm_ops,
+ .of_match_table = spi_geni_dt_match,
+ },
+};
+module_platform_driver(spi_geni_driver);
+
+MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/spi-geni-qcom.h b/include/linux/spi/spi-geni-qcom.h
new file mode 100644
index 0000000..dc95764
--- /dev/null
+++ b/include/linux/spi/spi-geni-qcom.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef __SPI_GENI_QCOM_HEADER___
+#define __SPI_GENI_QCOM_HEADER___
+
+struct spi_geni_qcom_ctrl_data {
+ u32 spi_cs_clk_delay;
+ u32 spi_inter_words_delay;
+};
+
+#endif /*__SPI_GENI_QCOM_HEADER___*/
--
1.9.1
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