--- /dev/null
+/*
+ * Marvell Armada-3700 SPI controller driver
+ *
+ * Copyright (C) 2016 Marvell Ltd.
+ *
+ * Author: Wilson Ding <dingwei@marvell.com>
+ * Author: Romain Perier <romain.perier@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME "armada_3700_spi"
+
+#define A3700_SPI_TIMEOUT 10
+
+/* SPI Register Offest */
+#define A3700_SPI_IF_CTRL_REG 0x00
+#define A3700_SPI_IF_CFG_REG 0x04
+#define A3700_SPI_DATA_OUT_REG 0x08
+#define A3700_SPI_DATA_IN_REG 0x0C
+#define A3700_SPI_IF_INST_REG 0x10
+#define A3700_SPI_IF_ADDR_REG 0x14
+#define A3700_SPI_IF_RMODE_REG 0x18
+#define A3700_SPI_IF_HDR_CNT_REG 0x1C
+#define A3700_SPI_IF_DIN_CNT_REG 0x20
+#define A3700_SPI_IF_TIME_REG 0x24
+#define A3700_SPI_INT_STAT_REG 0x28
+#define A3700_SPI_INT_MASK_REG 0x2C
+
+/* A3700_SPI_IF_CTRL_REG */
+#define A3700_SPI_EN BIT(16)
+#define A3700_SPI_ADDR_NOT_CONFIG BIT(12)
+#define A3700_SPI_WFIFO_OVERFLOW BIT(11)
+#define A3700_SPI_WFIFO_UNDERFLOW BIT(10)
+#define A3700_SPI_RFIFO_OVERFLOW BIT(9)
+#define A3700_SPI_RFIFO_UNDERFLOW BIT(8)
+#define A3700_SPI_WFIFO_FULL BIT(7)
+#define A3700_SPI_WFIFO_EMPTY BIT(6)
+#define A3700_SPI_RFIFO_FULL BIT(5)
+#define A3700_SPI_RFIFO_EMPTY BIT(4)
+#define A3700_SPI_WFIFO_RDY BIT(3)
+#define A3700_SPI_RFIFO_RDY BIT(2)
+#define A3700_SPI_XFER_RDY BIT(1)
+#define A3700_SPI_XFER_DONE BIT(0)
+
+/* A3700_SPI_IF_CFG_REG */
+#define A3700_SPI_WFIFO_THRS BIT(28)
+#define A3700_SPI_RFIFO_THRS BIT(24)
+#define A3700_SPI_AUTO_CS BIT(20)
+#define A3700_SPI_DMA_RD_EN BIT(18)
+#define A3700_SPI_FIFO_MODE BIT(17)
+#define A3700_SPI_SRST BIT(16)
+#define A3700_SPI_XFER_START BIT(15)
+#define A3700_SPI_XFER_STOP BIT(14)
+#define A3700_SPI_INST_PIN BIT(13)
+#define A3700_SPI_ADDR_PIN BIT(12)
+#define A3700_SPI_DATA_PIN1 BIT(11)
+#define A3700_SPI_DATA_PIN0 BIT(10)
+#define A3700_SPI_FIFO_FLUSH BIT(9)
+#define A3700_SPI_RW_EN BIT(8)
+#define A3700_SPI_CLK_POL BIT(7)
+#define A3700_SPI_CLK_PHA BIT(6)
+#define A3700_SPI_BYTE_LEN BIT(5)
+#define A3700_SPI_CLK_PRESCALE BIT(0)
+#define A3700_SPI_CLK_PRESCALE_MASK (0x1f)
+
+#define A3700_SPI_WFIFO_THRS_BIT 28
+#define A3700_SPI_RFIFO_THRS_BIT 24
+#define A3700_SPI_FIFO_THRS_MASK 0x7
+
+#define A3700_SPI_DATA_PIN_MASK 0x3
+
+/* A3700_SPI_IF_HDR_CNT_REG */
+#define A3700_SPI_DUMMY_CNT_BIT 12
+#define A3700_SPI_DUMMY_CNT_MASK 0x7
+#define A3700_SPI_RMODE_CNT_BIT 8
+#define A3700_SPI_RMODE_CNT_MASK 0x3
+#define A3700_SPI_ADDR_CNT_BIT 4
+#define A3700_SPI_ADDR_CNT_MASK 0x7
+#define A3700_SPI_INSTR_CNT_BIT 0
+#define A3700_SPI_INSTR_CNT_MASK 0x3
+
+/* A3700_SPI_IF_TIME_REG */
+#define A3700_SPI_CLK_CAPT_EDGE BIT(7)
+
+/* Flags and macros for struct a3700_spi */
+#define A3700_INSTR_CNT 1
+#define A3700_ADDR_CNT 3
+#define A3700_DUMMY_CNT 1
+
+struct a3700_spi {
+ struct spi_master *master;
+ void __iomem *base;
+ struct clk *clk;
+ unsigned int irq;
+ unsigned int flags;
+ bool xmit_data;
+ const u8 *tx_buf;
+ u8 *rx_buf;
+ size_t buf_len;
+ u8 byte_len;
+ u32 wait_mask;
+ struct completion done;
+ u32 addr_cnt;
+ u32 instr_cnt;
+ size_t hdr_cnt;
+};
+
+static u32 spireg_read(struct a3700_spi *a3700_spi, u32 offset)
+{
+ return readl(a3700_spi->base + offset);
+}
+
+static void spireg_write(struct a3700_spi *a3700_spi, u32 offset, u32 data)
+{
+ writel(data, a3700_spi->base + offset);
+}
+
+static void a3700_spi_auto_cs_unset(struct a3700_spi *a3700_spi)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~A3700_SPI_AUTO_CS;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static void a3700_spi_activate_cs(struct a3700_spi *a3700_spi, unsigned int cs)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+ val |= (A3700_SPI_EN << cs);
+ spireg_write(a3700_spi, A3700_SPI_IF_CTRL_REG, val);
+}
+
+static void a3700_spi_deactivate_cs(struct a3700_spi *a3700_spi,
+ unsigned int cs)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+ val &= ~(A3700_SPI_EN << cs);
+ spireg_write(a3700_spi, A3700_SPI_IF_CTRL_REG, val);
+}
+
+static int a3700_spi_pin_mode_set(struct a3700_spi *a3700_spi,
+ unsigned int pin_mode)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~(A3700_SPI_INST_PIN | A3700_SPI_ADDR_PIN);
+ val &= ~(A3700_SPI_DATA_PIN0 | A3700_SPI_DATA_PIN1);
+
+ switch (pin_mode) {
+ case 1:
+ break;
+ case 2:
+ val |= A3700_SPI_DATA_PIN0;
+ break;
+ case 4:
+ val |= A3700_SPI_DATA_PIN1;
+ break;
+ default:
+ dev_err(&a3700_spi->master->dev, "wrong pin mode %u", pin_mode);
+ return -EINVAL;
+ }
+
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ return 0;
+}
+
+static void a3700_spi_fifo_mode_set(struct a3700_spi *a3700_spi)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= A3700_SPI_FIFO_MODE;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static void a3700_spi_mode_set(struct a3700_spi *a3700_spi,
+ unsigned int mode_bits)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+
+ if (mode_bits & SPI_CPOL)
+ val |= A3700_SPI_CLK_POL;
+ else
+ val &= ~A3700_SPI_CLK_POL;
+
+ if (mode_bits & SPI_CPHA)
+ val |= A3700_SPI_CLK_PHA;
+ else
+ val &= ~A3700_SPI_CLK_PHA;
+
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static void a3700_spi_clock_set(struct a3700_spi *a3700_spi,
+ unsigned int speed_hz, u16 mode)
+{
+ u32 val;
+ u32 prescale;
+
+ prescale = DIV_ROUND_UP(clk_get_rate(a3700_spi->clk), speed_hz);
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val = val & ~A3700_SPI_CLK_PRESCALE_MASK;
+
+ val = val | (prescale & A3700_SPI_CLK_PRESCALE_MASK);
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ if (prescale <= 2) {
+ val = spireg_read(a3700_spi, A3700_SPI_IF_TIME_REG);
+ val |= A3700_SPI_CLK_CAPT_EDGE;
+ spireg_write(a3700_spi, A3700_SPI_IF_TIME_REG, val);
+ }
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~(A3700_SPI_CLK_POL | A3700_SPI_CLK_PHA);
+
+ if (mode & SPI_CPOL)
+ val |= A3700_SPI_CLK_POL;
+
+ if (mode & SPI_CPHA)
+ val |= A3700_SPI_CLK_PHA;
+
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static void a3700_spi_bytelen_set(struct a3700_spi *a3700_spi, unsigned int len)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ if (len == 4)
+ val |= A3700_SPI_BYTE_LEN;
+ else
+ val &= ~A3700_SPI_BYTE_LEN;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ a3700_spi->byte_len = len;
+}
+
+static int a3700_spi_fifo_flush(struct a3700_spi *a3700_spi)
+{
+ int timeout = A3700_SPI_TIMEOUT;
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= A3700_SPI_FIFO_FLUSH;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ while (--timeout) {
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ if (!(val & A3700_SPI_FIFO_FLUSH))
+ return 0;
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int a3700_spi_init(struct a3700_spi *a3700_spi)
+{
+ struct spi_master *master = a3700_spi->master;
+ u32 val;
+ int i, ret = 0;
+
+ /* Reset SPI unit */
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= A3700_SPI_SRST;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ udelay(A3700_SPI_TIMEOUT);
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~A3700_SPI_SRST;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ /* Disable AUTO_CS and deactivate all chip-selects */
+ a3700_spi_auto_cs_unset(a3700_spi);
+ for (i = 0; i < master->num_chipselect; i++)
+ a3700_spi_deactivate_cs(a3700_spi, i);
+
+ /* Enable FIFO mode */
+ a3700_spi_fifo_mode_set(a3700_spi);
+
+ /* Set SPI mode */
+ a3700_spi_mode_set(a3700_spi, master->mode_bits);
+
+ /* Reset counters */
+ spireg_write(a3700_spi, A3700_SPI_IF_HDR_CNT_REG, 0);
+ spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG, 0);
+
+ /* Mask the interrupts and clear cause bits */
+ spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
+ spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, ~0U);
+
+ return ret;
+}
+
+static irqreturn_t a3700_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = dev_id;
+ struct a3700_spi *a3700_spi;
+ u32 cause;
+
+ a3700_spi = spi_master_get_devdata(master);
+
+ /* Get interrupt causes */
+ cause = spireg_read(a3700_spi, A3700_SPI_INT_STAT_REG);
+
+ if (!cause || !(a3700_spi->wait_mask & cause))
+ return IRQ_NONE;
+
+ /* mask and acknowledge the SPI interrupts */
+ spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
+ spireg_write(a3700_spi, A3700_SPI_INT_STAT_REG, cause);
+
+ /* Wake up the transfer */
+ if (a3700_spi->wait_mask & cause)
+ complete(&a3700_spi->done);
+
+ return IRQ_HANDLED;
+}
+
+static bool a3700_spi_wait_completion(struct spi_device *spi)
+{
+ struct a3700_spi *a3700_spi;
+ unsigned int timeout;
+ unsigned int ctrl_reg;
+ unsigned long timeout_jiffies;
+
+ a3700_spi = spi_master_get_devdata(spi->master);
+
+ /* SPI interrupt is edge-triggered, which means an interrupt will
+ * be generated only when detecting a specific status bit changed
+ * from '0' to '1'. So when we start waiting for a interrupt, we
+ * need to check status bit in control reg first, if it is already 1,
+ * then we do not need to wait for interrupt
+ */
+ ctrl_reg = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+ if (a3700_spi->wait_mask & ctrl_reg)
+ return true;
+
+ reinit_completion(&a3700_spi->done);
+
+ spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG,
+ a3700_spi->wait_mask);
+
+ timeout_jiffies = msecs_to_jiffies(A3700_SPI_TIMEOUT);
+ timeout = wait_for_completion_timeout(&a3700_spi->done,
+ timeout_jiffies);
+
+ a3700_spi->wait_mask = 0;
+
+ if (timeout)
+ return true;
+
+ /* there might be the case that right after we checked the
+ * status bits in this routine and before start to wait for
+ * interrupt by wait_for_completion_timeout, the interrupt
+ * happens, to avoid missing it we need to double check
+ * status bits in control reg, if it is already 1, then
+ * consider that we have the interrupt successfully and
+ * return true.
+ */
+ ctrl_reg = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+ if (a3700_spi->wait_mask & ctrl_reg)
+ return true;
+
+ spireg_write(a3700_spi, A3700_SPI_INT_MASK_REG, 0);
+
+ return true;
+}
+
+static bool a3700_spi_transfer_wait(struct spi_device *spi,
+ unsigned int bit_mask)
+{
+ struct a3700_spi *a3700_spi;
+
+ a3700_spi = spi_master_get_devdata(spi->master);
+ a3700_spi->wait_mask = bit_mask;
+
+ return a3700_spi_wait_completion(spi);
+}
+
+static void a3700_spi_fifo_thres_set(struct a3700_spi *a3700_spi,
+ unsigned int bytes)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~(A3700_SPI_FIFO_THRS_MASK << A3700_SPI_RFIFO_THRS_BIT);
+ val |= (bytes - 1) << A3700_SPI_RFIFO_THRS_BIT;
+ val &= ~(A3700_SPI_FIFO_THRS_MASK << A3700_SPI_WFIFO_THRS_BIT);
+ val |= (7 - bytes) << A3700_SPI_WFIFO_THRS_BIT;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static void a3700_spi_transfer_setup(struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct a3700_spi *a3700_spi;
+ unsigned int byte_len;
+
+ a3700_spi = spi_master_get_devdata(spi->master);
+
+ a3700_spi_clock_set(a3700_spi, xfer->speed_hz, spi->mode);
+
+ byte_len = xfer->bits_per_word >> 3;
+
+ a3700_spi_fifo_thres_set(a3700_spi, byte_len);
+}
+
+static void a3700_spi_set_cs(struct spi_device *spi, bool enable)
+{
+ struct a3700_spi *a3700_spi = spi_master_get_devdata(spi->master);
+
+ if (!enable)
+ a3700_spi_activate_cs(a3700_spi, spi->chip_select);
+ else
+ a3700_spi_deactivate_cs(a3700_spi, spi->chip_select);
+}
+
+static void a3700_spi_header_set(struct a3700_spi *a3700_spi)
+{
+ u32 instr_cnt = 0, addr_cnt = 0, dummy_cnt = 0;
+ u32 val = 0;
+
+ /* Clear the header registers */
+ spireg_write(a3700_spi, A3700_SPI_IF_INST_REG, 0);
+ spireg_write(a3700_spi, A3700_SPI_IF_ADDR_REG, 0);
+ spireg_write(a3700_spi, A3700_SPI_IF_RMODE_REG, 0);
+
+ /* Set header counters */
+ if (a3700_spi->tx_buf) {
+ if (a3700_spi->buf_len <= a3700_spi->instr_cnt) {
+ instr_cnt = a3700_spi->buf_len;
+ } else if (a3700_spi->buf_len <= (a3700_spi->instr_cnt +
+ a3700_spi->addr_cnt)) {
+ instr_cnt = a3700_spi->instr_cnt;
+ addr_cnt = a3700_spi->buf_len - instr_cnt;
+ } else if (a3700_spi->buf_len <= a3700_spi->hdr_cnt) {
+ instr_cnt = a3700_spi->instr_cnt;
+ addr_cnt = a3700_spi->addr_cnt;
+ /* Need to handle the normal write case with 1 byte
+ * data
+ */
+ if (!a3700_spi->tx_buf[instr_cnt + addr_cnt])
+ dummy_cnt = a3700_spi->buf_len - instr_cnt -
+ addr_cnt;
+ }
+ val |= ((instr_cnt & A3700_SPI_INSTR_CNT_MASK)
+ << A3700_SPI_INSTR_CNT_BIT);
+ val |= ((addr_cnt & A3700_SPI_ADDR_CNT_MASK)
+ << A3700_SPI_ADDR_CNT_BIT);
+ val |= ((dummy_cnt & A3700_SPI_DUMMY_CNT_MASK)
+ << A3700_SPI_DUMMY_CNT_BIT);
+ }
+ spireg_write(a3700_spi, A3700_SPI_IF_HDR_CNT_REG, val);
+
+ /* Update the buffer length to be transferred */
+ a3700_spi->buf_len -= (instr_cnt + addr_cnt + dummy_cnt);
+
+ /* Set Instruction */
+ val = 0;
+ while (instr_cnt--) {
+ val = (val << 8) | a3700_spi->tx_buf[0];
+ a3700_spi->tx_buf++;
+ }
+ spireg_write(a3700_spi, A3700_SPI_IF_INST_REG, val);
+
+ /* Set Address */
+ val = 0;
+ while (addr_cnt--) {
+ val = (val << 8) | a3700_spi->tx_buf[0];
+ a3700_spi->tx_buf++;
+ }
+ spireg_write(a3700_spi, A3700_SPI_IF_ADDR_REG, val);
+}
+
+static int a3700_is_wfifo_full(struct a3700_spi *a3700_spi)
+{
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+ return (val & A3700_SPI_WFIFO_FULL);
+}
+
+static int a3700_spi_fifo_write(struct a3700_spi *a3700_spi)
+{
+ u32 val;
+ int i = 0;
+
+ while (!a3700_is_wfifo_full(a3700_spi) && a3700_spi->buf_len) {
+ val = 0;
+ if (a3700_spi->buf_len >= 4) {
+ val = cpu_to_le32(*(u32 *)a3700_spi->tx_buf);
+ spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG, val);
+
+ a3700_spi->buf_len -= 4;
+ a3700_spi->tx_buf += 4;
+ } else {
+ /*
+ * If the remained buffer length is less than 4-bytes,
+ * we should pad the write buffer with all ones. So that
+ * it avoids overwrite the unexpected bytes following
+ * the last one.
+ */
+ val = GENMASK(31, 0);
+ while (a3700_spi->buf_len) {
+ val &= ~(0xff << (8 * i));
+ val |= *a3700_spi->tx_buf++ << (8 * i);
+ i++;
+ a3700_spi->buf_len--;
+
+ spireg_write(a3700_spi, A3700_SPI_DATA_OUT_REG,
+ val);
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int a3700_is_rfifo_empty(struct a3700_spi *a3700_spi)
+{
+ u32 val = spireg_read(a3700_spi, A3700_SPI_IF_CTRL_REG);
+
+ return (val & A3700_SPI_RFIFO_EMPTY);
+}
+
+static int a3700_spi_fifo_read(struct a3700_spi *a3700_spi)
+{
+ u32 val;
+
+ while (!a3700_is_rfifo_empty(a3700_spi) && a3700_spi->buf_len) {
+ val = spireg_read(a3700_spi, A3700_SPI_DATA_IN_REG);
+ if (a3700_spi->buf_len >= 4) {
+ u32 data = le32_to_cpu(val);
+ memcpy(a3700_spi->rx_buf, &data, 4);
+
+ a3700_spi->buf_len -= 4;
+ a3700_spi->rx_buf += 4;
+ } else {
+ /*
+ * When remain bytes is not larger than 4, we should
+ * avoid memory overwriting and just write the left rx
+ * buffer bytes.
+ */
+ while (a3700_spi->buf_len) {
+ *a3700_spi->rx_buf = val & 0xff;
+ val >>= 8;
+
+ a3700_spi->buf_len--;
+ a3700_spi->rx_buf++;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void a3700_spi_transfer_abort_fifo(struct a3700_spi *a3700_spi)
+{
+ int timeout = A3700_SPI_TIMEOUT;
+ u32 val;
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= A3700_SPI_XFER_STOP;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ while (--timeout) {
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ if (!(val & A3700_SPI_XFER_START))
+ break;
+ udelay(1);
+ }
+
+ a3700_spi_fifo_flush(a3700_spi);
+
+ val &= ~A3700_SPI_XFER_STOP;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+}
+
+static int a3700_spi_prepare_message(struct spi_master *master,
+ struct spi_message *message)
+{
+ struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
+ struct spi_device *spi = message->spi;
+ int ret;
+
+ ret = clk_enable(a3700_spi->clk);
+ if (ret) {
+ dev_err(&spi->dev, "failed to enable clk with error %d\n", ret);
+ return ret;
+ }
+
+ /* Flush the FIFOs */
+ ret = a3700_spi_fifo_flush(a3700_spi);
+ if (ret)
+ return ret;
+
+ a3700_spi_bytelen_set(a3700_spi, 4);
+
+ return 0;
+}
+
+static int a3700_spi_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
+ int ret = 0, timeout = A3700_SPI_TIMEOUT;
+ unsigned int nbits = 0;
+ u32 val;
+
+ a3700_spi_transfer_setup(spi, xfer);
+
+ a3700_spi->tx_buf = xfer->tx_buf;
+ a3700_spi->rx_buf = xfer->rx_buf;
+ a3700_spi->buf_len = xfer->len;
+
+ /* SPI transfer headers */
+ a3700_spi_header_set(a3700_spi);
+
+ if (xfer->tx_buf)
+ nbits = xfer->tx_nbits;
+ else if (xfer->rx_buf)
+ nbits = xfer->rx_nbits;
+
+ a3700_spi_pin_mode_set(a3700_spi, nbits);
+
+ if (xfer->rx_buf) {
+ /* Set read data length */
+ spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG,
+ a3700_spi->buf_len);
+ /* Start READ transfer */
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val &= ~A3700_SPI_RW_EN;
+ val |= A3700_SPI_XFER_START;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+ } else if (xfer->tx_buf) {
+ /* Start Write transfer */
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= (A3700_SPI_XFER_START | A3700_SPI_RW_EN);
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+
+ /*
+ * If there are data to be written to the SPI device, xmit_data
+ * flag is set true; otherwise the instruction in SPI_INSTR does
+ * not require data to be written to the SPI device, then
+ * xmit_data flag is set false.
+ */
+ a3700_spi->xmit_data = (a3700_spi->buf_len != 0);
+ }
+
+ while (a3700_spi->buf_len) {
+ if (a3700_spi->tx_buf) {
+ /* Wait wfifo ready */
+ if (!a3700_spi_transfer_wait(spi,
+ A3700_SPI_WFIFO_RDY)) {
+ dev_err(&spi->dev,
+ "wait wfifo ready timed out\n");
+ ret = -ETIMEDOUT;
+ goto error;
+ }
+ /* Fill up the wfifo */
+ ret = a3700_spi_fifo_write(a3700_spi);
+ if (ret)
+ goto error;
+ } else if (a3700_spi->rx_buf) {
+ /* Wait rfifo ready */
+ if (!a3700_spi_transfer_wait(spi,
+ A3700_SPI_RFIFO_RDY)) {
+ dev_err(&spi->dev,
+ "wait rfifo ready timed out\n");
+ ret = -ETIMEDOUT;
+ goto error;
+ }
+ /* Drain out the rfifo */
+ ret = a3700_spi_fifo_read(a3700_spi);
+ if (ret)
+ goto error;
+ }
+ }
+
+ /*
+ * Stop a write transfer in fifo mode:
+ * - wait all the bytes in wfifo to be shifted out
+ * - set XFER_STOP bit
+ * - wait XFER_START bit clear
+ * - clear XFER_STOP bit
+ * Stop a read transfer in fifo mode:
+ * - the hardware is to reset the XFER_START bit
+ * after the number of bytes indicated in DIN_CNT
+ * register
+ * - just wait XFER_START bit clear
+ */
+ if (a3700_spi->tx_buf) {
+ if (a3700_spi->xmit_data) {
+ /*
+ * If there are data written to the SPI device, wait
+ * until SPI_WFIFO_EMPTY is 1 to wait for all data to
+ * transfer out of write FIFO.
+ */
+ if (!a3700_spi_transfer_wait(spi,
+ A3700_SPI_WFIFO_EMPTY)) {
+ dev_err(&spi->dev, "wait wfifo empty timed out\n");
+ return -ETIMEDOUT;
+ }
+ } else {
+ /*
+ * If the instruction in SPI_INSTR does not require data
+ * to be written to the SPI device, wait until SPI_RDY
+ * is 1 for the SPI interface to be in idle.
+ */
+ if (!a3700_spi_transfer_wait(spi, A3700_SPI_XFER_RDY)) {
+ dev_err(&spi->dev, "wait xfer ready timed out\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ val |= A3700_SPI_XFER_STOP;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+ }
+
+ while (--timeout) {
+ val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
+ if (!(val & A3700_SPI_XFER_START))
+ break;
+ udelay(1);
+ }
+
+ if (timeout == 0) {
+ dev_err(&spi->dev, "wait transfer start clear timed out\n");
+ ret = -ETIMEDOUT;
+ goto error;
+ }
+
+ val &= ~A3700_SPI_XFER_STOP;
+ spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
+ goto out;
+
+error:
+ a3700_spi_transfer_abort_fifo(a3700_spi);
+out:
+ spi_finalize_current_transfer(master);
+
+ return ret;
+}
+
+static int a3700_spi_unprepare_message(struct spi_master *master,
+ struct spi_message *message)
+{
+ struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
+
+ clk_disable(a3700_spi->clk);
+
+ return 0;
+}
+
+static const struct of_device_id a3700_spi_dt_ids[] = {
+ { .compatible = "marvell,armada-3700-spi", .data = NULL },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, a3700_spi_dt_ids);
+
+static int a3700_spi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *of_node = dev->of_node;
+ struct resource *res;
+ struct spi_master *master;
+ struct a3700_spi *spi;
+ u32 num_cs = 0;
+ int ret = 0;
+
+ master = spi_alloc_master(dev, sizeof(*spi));
+ if (!master) {
+ dev_err(dev, "master allocation failed\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (of_property_read_u32(of_node, "num-cs", &num_cs)) {
+ dev_err(dev, "could not find num-cs\n");
+ ret = -ENXIO;
+ goto error;
+ }
+
+ master->bus_num = pdev->id;
+ master->dev.of_node = of_node;
+ master->mode_bits = SPI_MODE_3;
+ master->num_chipselect = num_cs;
+ master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(32);
+ master->prepare_message = a3700_spi_prepare_message;
+ master->transfer_one = a3700_spi_transfer_one;
+ master->unprepare_message = a3700_spi_unprepare_message;
+ master->set_cs = a3700_spi_set_cs;
+ master->flags = SPI_MASTER_HALF_DUPLEX;
+ master->mode_bits |= (SPI_RX_DUAL | SPI_RX_DUAL |
+ SPI_RX_QUAD | SPI_TX_QUAD);
+
+ platform_set_drvdata(pdev, master);
+
+ spi = spi_master_get_devdata(master);
+ memset(spi, 0, sizeof(struct a3700_spi));
+
+ spi->master = master;
+ spi->instr_cnt = A3700_INSTR_CNT;
+ spi->addr_cnt = A3700_ADDR_CNT;
+ spi->hdr_cnt = A3700_INSTR_CNT + A3700_ADDR_CNT +
+ A3700_DUMMY_CNT;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ spi->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(spi->base)) {
+ ret = PTR_ERR(spi->base);
+ goto error;
+ }
+
+ spi->irq = platform_get_irq(pdev, 0);
+ if (spi->irq < 0) {
+ dev_err(dev, "could not get irq: %d\n", spi->irq);
+ ret = -ENXIO;
+ goto error;
+ }
+
+ init_completion(&spi->done);
+
+ spi->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(spi->clk)) {
+ dev_err(dev, "could not find clk: %ld\n", PTR_ERR(spi->clk));
+ goto error;
+ }
+
+ ret = clk_prepare(spi->clk);
+ if (ret) {
+ dev_err(dev, "could not prepare clk: %d\n", ret);
+ goto error;
+ }
+
+ ret = a3700_spi_init(spi);
+ if (ret)
+ goto error_clk;
+
+ ret = devm_request_irq(dev, spi->irq, a3700_spi_interrupt, 0,
+ dev_name(dev), master);
+ if (ret) {
+ dev_err(dev, "could not request IRQ: %d\n", ret);
+ goto error_clk;
+ }
+
+ ret = devm_spi_register_master(dev, master);
+ if (ret) {
+ dev_err(dev, "Failed to register master\n");
+ goto error_clk;
+ }
+
+ return 0;
+
+error_clk:
+ clk_disable_unprepare(spi->clk);
+error:
+ spi_master_put(master);
+out:
+ return ret;
+}
+
+static int a3700_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct a3700_spi *spi = spi_master_get_devdata(master);
+
+ clk_unprepare(spi->clk);
+ spi_master_put(master);
+
+ return 0;
+}
+
+static struct platform_driver a3700_spi_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(a3700_spi_dt_ids),
+ },
+ .probe = a3700_spi_probe,
+ .remove = a3700_spi_remove,
+};
+
+module_platform_driver(a3700_spi_driver);
+
+MODULE_DESCRIPTION("Armada-3700 SPI driver");
+MODULE_AUTHOR("Wilson Ding <dingwei@marvell.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);
projects / platform / kernel / linux-rpi3.git / commitdiff