Hi Felipe,
Hi,
On Sun, Aug 04, 2013 at 02:28:09PM +0530, Sourav Poddar wrote:
diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
new file mode 100644
index 0000000..4328ae2
--- /dev/null
+++ b/drivers/spi/spi-ti-qspi.c
@@ -0,0 +1,591 @@
+/*
+ * TI QSPI driver
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Sourav Poddar<sourav.poddar@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GPLv2.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include<linux/kernel.h>
+#include<linux/init.h>
+#include<linux/interrupt.h>
+#include<linux/module.h>
+#include<linux/device.h>
+#include<linux/delay.h>
+#include<linux/dma-mapping.h>
+#include<linux/dmaengine.h>
+#include<linux/omap-dma.h>
+#include<linux/platform_device.h>
+#include<linux/err.h>
+#include<linux/clk.h>
+#include<linux/io.h>
+#include<linux/slab.h>
+#include<linux/pm_runtime.h>
+#include<linux/of.h>
+#include<linux/of_device.h>
+#include<linux/pinctrl/consumer.h>
+
+#include<linux/spi/spi.h>
+
+struct ti_qspi_regs {
+ u32 clkctrl;
+};
+
+struct ti_qspi {
+ struct completion transfer_complete;
+
+ /* IRQ synchronization */
+ spinlock_t lock;
+
+ /* list synchronization */
+ struct mutex list_lock;
+
+ struct spi_master *master;
+ void __iomem *base;
+ struct clk *fclk;
+ struct device *dev;
+
+ struct ti_qspi_regs ctx_reg;
+
+ u32 spi_max_frequency;
+ u32 cmd;
+ u32 dc;
+ u32 stat;
+};
+
+#define QSPI_PID (0x0)
+#define QSPI_SYSCONFIG (0x10)
+#define QSPI_INTR_STATUS_RAW_SET (0x20)
+#define QSPI_INTR_STATUS_ENABLED_CLEAR (0x24)
+#define QSPI_INTR_ENABLE_SET_REG (0x28)
+#define QSPI_INTR_ENABLE_CLEAR_REG (0x2c)
+#define QSPI_SPI_CLOCK_CNTRL_REG (0x40)
+#define QSPI_SPI_DC_REG (0x44)
+#define QSPI_SPI_CMD_REG (0x48)
+#define QSPI_SPI_STATUS_REG (0x4c)
+#define QSPI_SPI_DATA_REG (0x50)
+#define QSPI_SPI_SETUP0_REG (0x54)
+#define QSPI_SPI_SWITCH_REG (0x64)
+#define QSPI_SPI_SETUP1_REG (0x58)
+#define QSPI_SPI_SETUP2_REG (0x5c)
+#define QSPI_SPI_SETUP3_REG (0x60)
+#define QSPI_SPI_DATA_REG_1 (0x68)
+#define QSPI_SPI_DATA_REG_2 (0x6c)
+#define QSPI_SPI_DATA_REG_3 (0x70)
+
+#define QSPI_COMPLETION_TIMEOUT msecs_to_jiffies(2000)
+
+#define QSPI_FCLK 192000000
+
+/* Clock Control */
+#define QSPI_CLK_EN (1<< 31)
+#define QSPI_CLK_DIV_MAX 0xffff
+
+/* Command */
+#define QSPI_EN_CS(n) (n<< 28)
+#define QSPI_WLEN(n) ((n-1)<< 19)
spaces around '-'
+#define QSPI_3_PIN (1<< 18)
+#define QSPI_RD_SNGL (1<< 16)
+#define QSPI_WR_SNGL (2<< 16)
+#define QSPI_RD_DUAL (3<< 16)
+#define QSPI_RD_QUAD (7<< 16)
+#define QSPI_INVAL (4<< 16)
+#define QSPI_WC_CMD_INT_EN (1<< 14)
+#define QSPI_FLEN(n) ((n-1)<< 0)
spaces around '-'
Ok.
+/* STATUS REGISTER */
+#define WC 0x02
+
+/* INTERRUPT REGISTER */
+#define QSPI_WC_INT_EN (1<< 1)
+#define QSPI_WC_INT_DISABLE (1<< 1)
+
+/* Device Control */
+#define QSPI_DD(m, n) (m<< (3 + n * 8))
+#define QSPI_CKPHA(n) (1<< (2 + n * 8))
+#define QSPI_CSPOL(n) (1<< (1 + n * 8))
+#define QSPI_CKPOL(n) (1<< (n*8))
spaces around '*'
Ok.
+#define QSPI_FRAME 4096
+
+#define QSPI_AUTOSUSPEND_TIMEOUT 2000
+
+static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
+ unsigned long reg)
+{
+ return readl(qspi->base + reg);
+}
+
+static inline void ti_qspi_write(struct ti_qspi *qspi,
+ unsigned long val, unsigned long reg)
+{
+ writel(val, qspi->base + reg);
+}
+
+static int ti_qspi_setup(struct spi_device *spi)
+{
+ struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
+ struct ti_qspi_regs *ctx_reg =&qspi->ctx_reg;
+ int clk_div = 0, ret;
+ u32 clk_ctrl_reg, clk_rate, clk_mask;
+
+ if (spi->master->busy) {
+ dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
+ return -EBUSY;
+ }
+
+ if (!qspi->spi_max_frequency) {
+ dev_err(qspi->dev, "spi max frequency not defined\n");
+ return -EINVAL;
+ }
+
+ clk_rate = clk_get_rate(qspi->fclk);
+
+ clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
+
+ if (clk_div< 0) {
+ dev_dbg(qspi->dev, "%s: clock divider< 0, using /1 divider\n",
+ __func__);
do you really need to print the function name ?
Actually, no, was just useful for initial debug purpose.
+ return -EINVAL;
+ }
+
+ if (clk_div> QSPI_CLK_DIV_MAX) {
+ dev_dbg(qspi->dev, "%s: clock divider>%d , using /%d divider\n",
+ __func__, QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
do you really need to print the function name ?
Same as above.
+ return -EINVAL;
+ }
+
+ dev_dbg(qspi->dev, "%s: hz: %d, clock divider %d\n", __func__,
do you really need to print the function name ?
no.
+ qspi->spi_max_frequency, clk_div);
+
+ ret = pm_runtime_get_sync(qspi->dev);
+ if (ret) {
+ dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
+ return ret;
+ }
+
+ clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
+
+ clk_ctrl_reg&= ~QSPI_CLK_EN;
+
+ /* disable SCLK */
+ ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
+
+ /* enable SCLK */
+ clk_mask = QSPI_CLK_EN | clk_div;
+ ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
+ ctx_reg->clkctrl = clk_mask;
+
+ pm_runtime_mark_last_busy(qspi->dev);
+ ret = pm_runtime_put_autosuspend(qspi->dev);
+ if (ret< 0) {
+ dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
+{
+ struct ti_qspi_regs *ctx_reg =&qspi->ctx_reg;
+
+ ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
+}
+
+static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
+{
+ int wlen, count, ret;
+
+ count = t->len;
+ wlen = t->bits_per_word;
+
+ if (wlen == 8) {
+ const u8 *txbuf;
+ txbuf = t->tx_buf;
+ do {
+ dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
+ qspi->cmd | QSPI_WR_SNGL, qspi->dc, *txbuf);
create a local 'cmd' variable so you don't have to repeat:
qspi->cmd | QSPI_WR_SNGL
all the time
Ok.
+ writeb(*txbuf++, qspi->base + QSPI_SPI_DATA_REG);
+ ti_qspi_write(qspi, qspi->cmd | QSPI_WR_SNGL,
+ QSPI_SPI_CMD_REG);
+ ret = wait_for_completion_timeout(&qspi->transfer_complete,
+ QSPI_COMPLETION_TIMEOUT);
+ if (ret == 0) {
+ dev_err(qspi->dev, "write timed out\n");
+ return -ETIMEDOUT;
+ }
+ count -= 1;
+ } while (count);
+ } else if (wlen == 16) {
+ const u16 *txbuf;
+ txbuf = t->tx_buf;
+ do {
+ dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
+ qspi->cmd | QSPI_WR_SNGL, qspi->dc, *txbuf);
+ writew(*txbuf++, qspi->base + QSPI_SPI_DATA_REG);
+ ti_qspi_write(qspi, qspi->cmd | QSPI_WR_SNGL,
+ QSPI_SPI_CMD_REG);
+ ret = wait_for_completion_timeout(&qspi->transfer_complete,
+ QSPI_COMPLETION_TIMEOUT);
+ if (ret == 0) {
+ dev_err(qspi->dev, "write timed out\n");
+ return -ETIMEDOUT;
+ }
+ count -= 2;
+ } while (count>= 2);
while (count) is enough here too.
Ok.
+ } else if (wlen == 32) {
if else if else if else if .... this looks like a switch to me. I know
someone else commented that switch wasn't the best construct, but to my
eyes, switch looks a lot cleaner.
My previous switch implementation was implemented as a seperate
function, as a result of which there was the need to pass pointers, other
variables, then collect it as a double pointer, making things a bit untidy.
What I can do is to convert these portion into switch here itself, which
will
make the code a lot more cleaner. ?
+ const u32 *txbuf;
+ txbuf = t->tx_buf;
+ do {
+ dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
+ qspi->cmd | QSPI_WR_SNGL, qspi->dc, *txbuf);
+ writel(*txbuf++, qspi->base + QSPI_SPI_DATA_REG);
+ ti_qspi_write(qspi, qspi->cmd | QSPI_WR_SNGL,
+ QSPI_SPI_CMD_REG);
+ ret = wait_for_completion_timeout(&qspi->transfer_complete,
+ QSPI_COMPLETION_TIMEOUT);
+ if (ret == 0) {
+ dev_err(qspi->dev, "write timed out\n");
+ return -ETIMEDOUT;
+ }
+ count -= 4;
+ } while (count>= 4);
and here.
these coments apply to qspi_read_msg() too
+static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
+{
+ int ret;
+
+ if (t->tx_buf) {
+ ret = qspi_write_msg(qspi, t);
+ if (ret) {
+ dev_dbg(qspi->dev, "Error while writing\n");
+ return ret;
+ }
+ }
+
+ if (t->rx_buf) {
+ ret = qspi_read_msg(qspi, t);
+ if (ret) {
+ dev_dbg(qspi->dev, "Error while writing\n");
error while "READING" ??
My bad. Will chnage this.
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