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path: root/drivers/spi/spi-imx.c
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Diffstat (limited to 'drivers/spi/spi-imx.c')
-rw-r--r--drivers/spi/spi-imx.c210
1 files changed, 123 insertions, 87 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index c6e697f5e00..5daff2054ae 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -23,7 +23,6 @@
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
-#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
@@ -38,7 +37,7 @@
#include <linux/of_device.h>
#include <linux/of_gpio.h>
-#include <mach/spi.h>
+#include <linux/platform_data/spi-imx.h>
#define DRIVER_NAME "spi_imx"
@@ -83,9 +82,10 @@ struct spi_imx_data {
struct spi_bitbang bitbang;
struct completion xfer_done;
- void *base;
+ void __iomem *base;
int irq;
- struct clk *clk;
+ struct clk *clk_per;
+ struct clk *clk_ipg;
unsigned long spi_clk;
unsigned int count;
@@ -95,7 +95,7 @@ struct spi_imx_data {
const void *tx_buf;
unsigned int txfifo; /* number of words pushed in tx FIFO */
- struct spi_imx_devtype_data *devtype_data;
+ const struct spi_imx_devtype_data *devtype_data;
int chipselect[0];
};
@@ -195,6 +195,7 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin,
#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4))
#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8))
#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12))
+#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs) + 20))
#define MX51_ECSPI_INT 0x10
#define MX51_ECSPI_INT_TEEN (1 << 0)
@@ -204,7 +205,8 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin,
#define MX51_ECSPI_STAT_RR (1 << 3)
/* MX51 eCSPI */
-static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi)
+static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
+ unsigned int *fres)
{
/*
* there are two 4-bit dividers, the pre-divider divides by
@@ -232,6 +234,10 @@ static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi)
pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
__func__, fin, fspi, post, pre);
+
+ /* Resulting frequency for the SCLK line. */
+ *fres = (fin / (pre + 1)) >> post;
+
return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
}
@@ -262,6 +268,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0;
+ u32 clk = config->speed_hz, delay;
/*
* The hardware seems to have a race condition when changing modes. The
@@ -273,7 +280,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
/* set clock speed */
- ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz);
+ ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
/* set chip select to use */
ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
@@ -285,15 +292,33 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
if (config->mode & SPI_CPHA)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
- if (config->mode & SPI_CPOL)
+ if (config->mode & SPI_CPOL) {
cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
-
+ cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
+ }
if (config->mode & SPI_CS_HIGH)
cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
+ /*
+ * Wait until the changes in the configuration register CONFIGREG
+ * propagate into the hardware. It takes exactly one tick of the
+ * SCLK clock, but we will wait two SCLK clock just to be sure. The
+ * effect of the delay it takes for the hardware to apply changes
+ * is noticable if the SCLK clock run very slow. In such a case, if
+ * the polarity of SCLK should be inverted, the GPIO ChipSelect might
+ * be asserted before the SCLK polarity changes, which would disrupt
+ * the SPI communication as the device on the other end would consider
+ * the change of SCLK polarity as a clock tick already.
+ */
+ delay = (2 * 1000000) / clk;
+ if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
+ udelay(delay);
+ else /* SCLK is _very_ slow */
+ usleep_range(delay, delay + 10);
+
return 0;
}
@@ -616,6 +641,7 @@ static const struct of_device_id spi_imx_dt_ids[] = {
{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
{ /* sentinel */ }
};
+MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
static void spi_imx_chipselect(struct spi_device *spi, int is_active)
{
@@ -624,7 +650,7 @@ static void spi_imx_chipselect(struct spi_device *spi, int is_active)
int active = is_active != BITBANG_CS_INACTIVE;
int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
- if (gpio < 0)
+ if (!gpio_is_valid(gpio))
return;
gpio_set_value(gpio, dev_is_lowactive ^ active);
@@ -686,8 +712,6 @@ static int spi_imx_setupxfer(struct spi_device *spi,
config.speed_hz = spi->max_speed_hz;
if (!config.bpw)
config.bpw = spi->bits_per_word;
- if (!config.speed_hz)
- config.speed_hz = spi->max_speed_hz;
/* Initialize the functions for transfer */
if (config.bpw <= 8) {
@@ -696,11 +720,10 @@ static int spi_imx_setupxfer(struct spi_device *spi,
} else if (config.bpw <= 16) {
spi_imx->rx = spi_imx_buf_rx_u16;
spi_imx->tx = spi_imx_buf_tx_u16;
- } else if (config.bpw <= 32) {
+ } else {
spi_imx->rx = spi_imx_buf_rx_u32;
spi_imx->tx = spi_imx_buf_tx_u32;
- } else
- BUG();
+ }
spi_imx->devtype_data->config(spi_imx, &config);
@@ -717,7 +740,7 @@ static int spi_imx_transfer(struct spi_device *spi,
spi_imx->count = transfer->len;
spi_imx->txfifo = 0;
- init_completion(&spi_imx->xfer_done);
+ reinit_completion(&spi_imx->xfer_done);
spi_imx_push(spi_imx);
@@ -736,7 +759,7 @@ static int spi_imx_setup(struct spi_device *spi)
dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
spi->mode, spi->bits_per_word, spi->max_speed_hz);
- if (gpio >= 0)
+ if (gpio_is_valid(gpio))
gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
@@ -748,7 +771,36 @@ static void spi_imx_cleanup(struct spi_device *spi)
{
}
-static int __devinit spi_imx_probe(struct platform_device *pdev)
+static int
+spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
+{
+ struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_enable(spi_imx->clk_per);
+ if (ret)
+ return ret;
+
+ ret = clk_enable(spi_imx->clk_ipg);
+ if (ret) {
+ clk_disable(spi_imx->clk_per);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int
+spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
+{
+ struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+ clk_disable(spi_imx->clk_ipg);
+ clk_disable(spi_imx->clk_per);
+ return 0;
+}
+
+static int spi_imx_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
@@ -766,8 +818,12 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
}
ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
- if (ret < 0)
- num_cs = mxc_platform_info->num_chipselect;
+ if (ret < 0) {
+ if (mxc_platform_info)
+ num_cs = mxc_platform_info->num_chipselect;
+ else
+ return ret;
+ }
master = spi_alloc_master(&pdev->dev,
sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
@@ -776,28 +832,25 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, master);
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
master->bus_num = pdev->id;
master->num_chipselect = num_cs;
spi_imx = spi_master_get_devdata(master);
- spi_imx->bitbang.master = spi_master_get(master);
+ spi_imx->bitbang.master = master;
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
- if (cs_gpio < 0)
+ if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
cs_gpio = mxc_platform_info->chipselect[i];
spi_imx->chipselect[i] = cs_gpio;
- if (cs_gpio < 0)
+ if (!gpio_is_valid(cs_gpio))
continue;
- ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
+ ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i],
+ DRIVER_NAME);
if (ret) {
- while (i > 0) {
- i--;
- if (spi_imx->chipselect[i] >= 0)
- gpio_free(spi_imx->chipselect[i]);
- }
dev_err(&pdev->dev, "can't get cs gpios\n");
goto out_master_put;
}
@@ -808,6 +861,8 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
spi_imx->bitbang.master->setup = spi_imx_setup;
spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
+ spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
+ spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
init_completion(&spi_imx->xfer_done);
@@ -816,45 +871,46 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "can't get platform resource\n");
- ret = -ENOMEM;
- goto out_gpio_free;
- }
-
- if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
- dev_err(&pdev->dev, "request_mem_region failed\n");
- ret = -EBUSY;
- goto out_gpio_free;
- }
-
- spi_imx->base = ioremap(res->start, resource_size(res));
- if (!spi_imx->base) {
- ret = -EINVAL;
- goto out_release_mem;
+ spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spi_imx->base)) {
+ ret = PTR_ERR(spi_imx->base);
+ goto out_master_put;
}
spi_imx->irq = platform_get_irq(pdev, 0);
if (spi_imx->irq < 0) {
- ret = -EINVAL;
- goto out_iounmap;
+ ret = spi_imx->irq;
+ goto out_master_put;
}
- ret = request_irq(spi_imx->irq, spi_imx_isr, 0, DRIVER_NAME, spi_imx);
+ ret = devm_request_irq(&pdev->dev, spi_imx->irq, spi_imx_isr, 0,
+ dev_name(&pdev->dev), spi_imx);
if (ret) {
dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
- goto out_iounmap;
+ goto out_master_put;
+ }
+
+ spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(spi_imx->clk_ipg)) {
+ ret = PTR_ERR(spi_imx->clk_ipg);
+ goto out_master_put;
}
- spi_imx->clk = clk_get(&pdev->dev, NULL);
- if (IS_ERR(spi_imx->clk)) {
- dev_err(&pdev->dev, "unable to get clock\n");
- ret = PTR_ERR(spi_imx->clk);
- goto out_free_irq;
+ spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
+ if (IS_ERR(spi_imx->clk_per)) {
+ ret = PTR_ERR(spi_imx->clk_per);
+ goto out_master_put;
}
- clk_enable(spi_imx->clk);
- spi_imx->spi_clk = clk_get_rate(spi_imx->clk);
+ ret = clk_prepare_enable(spi_imx->clk_per);
+ if (ret)
+ goto out_master_put;
+
+ ret = clk_prepare_enable(spi_imx->clk_ipg);
+ if (ret)
+ goto out_put_per;
+
+ spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
spi_imx->devtype_data->reset(spi_imx);
@@ -869,53 +925,32 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "probed\n");
+ clk_disable(spi_imx->clk_ipg);
+ clk_disable(spi_imx->clk_per);
return ret;
out_clk_put:
- clk_disable(spi_imx->clk);
- clk_put(spi_imx->clk);
-out_free_irq:
- free_irq(spi_imx->irq, spi_imx);
-out_iounmap:
- iounmap(spi_imx->base);
-out_release_mem:
- release_mem_region(res->start, resource_size(res));
-out_gpio_free:
- for (i = 0; i < master->num_chipselect; i++)
- if (spi_imx->chipselect[i] >= 0)
- gpio_free(spi_imx->chipselect[i]);
+ clk_disable_unprepare(spi_imx->clk_ipg);
+out_put_per:
+ clk_disable_unprepare(spi_imx->clk_per);
out_master_put:
spi_master_put(master);
- kfree(master);
- platform_set_drvdata(pdev, NULL);
+
return ret;
}
-static int __devexit spi_imx_remove(struct platform_device *pdev)
+static int spi_imx_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
- int i;
spi_bitbang_stop(&spi_imx->bitbang);
writel(0, spi_imx->base + MXC_CSPICTRL);
- clk_disable(spi_imx->clk);
- clk_put(spi_imx->clk);
- free_irq(spi_imx->irq, spi_imx);
- iounmap(spi_imx->base);
-
- for (i = 0; i < master->num_chipselect; i++)
- if (spi_imx->chipselect[i] >= 0)
- gpio_free(spi_imx->chipselect[i]);
-
+ clk_unprepare(spi_imx->clk_ipg);
+ clk_unprepare(spi_imx->clk_per);
spi_master_put(master);
- release_mem_region(res->start, resource_size(res));
-
- platform_set_drvdata(pdev, NULL);
-
return 0;
}
@@ -927,10 +962,11 @@ static struct platform_driver spi_imx_driver = {
},
.id_table = spi_imx_devtype,
.probe = spi_imx_probe,
- .remove = __devexit_p(spi_imx_remove),
+ .remove = spi_imx_remove,
};
module_platform_driver(spi_imx_driver);
MODULE_DESCRIPTION("SPI Master Controller driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);