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path: root/drivers/spi/spi_s3c24xx.c
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Diffstat (limited to 'drivers/spi/spi_s3c24xx.c')
-rw-r--r--drivers/spi/spi_s3c24xx.c159
1 files changed, 106 insertions, 53 deletions
diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c
index 3f3119d760db..33d94f76b9ef 100644
--- a/drivers/spi/spi_s3c24xx.c
+++ b/drivers/spi/spi_s3c24xx.c
@@ -20,17 +20,28 @@
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
+#include <linux/io.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
-#include <asm/io.h>
-#include <asm/dma.h>
-#include <mach/hardware.h>
-
#include <plat/regs-spi.h>
#include <mach/spi.h>
+/**
+ * s3c24xx_spi_devstate - per device data
+ * @hz: Last frequency calculated for @sppre field.
+ * @mode: Last mode setting for the @spcon field.
+ * @spcon: Value to write to the SPCON register.
+ * @sppre: Value to write to the SPPRE register.
+ */
+struct s3c24xx_spi_devstate {
+ unsigned int hz;
+ unsigned int mode;
+ u8 spcon;
+ u8 sppre;
+};
+
struct s3c24xx_spi {
/* bitbang has to be first */
struct spi_bitbang bitbang;
@@ -71,43 +82,31 @@ static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
{
+ struct s3c24xx_spi_devstate *cs = spi->controller_state;
struct s3c24xx_spi *hw = to_hw(spi);
unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
- unsigned int spcon;
+
+ /* change the chipselect state and the state of the spi engine clock */
switch (value) {
case BITBANG_CS_INACTIVE:
hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
+ writeb(cs->spcon, hw->regs + S3C2410_SPCON);
break;
case BITBANG_CS_ACTIVE:
- spcon = readb(hw->regs + S3C2410_SPCON);
-
- if (spi->mode & SPI_CPHA)
- spcon |= S3C2410_SPCON_CPHA_FMTB;
- else
- spcon &= ~S3C2410_SPCON_CPHA_FMTB;
-
- if (spi->mode & SPI_CPOL)
- spcon |= S3C2410_SPCON_CPOL_HIGH;
- else
- spcon &= ~S3C2410_SPCON_CPOL_HIGH;
-
- spcon |= S3C2410_SPCON_ENSCK;
-
- /* write new configration */
-
- writeb(spcon, hw->regs + S3C2410_SPCON);
+ writeb(cs->spcon | S3C2410_SPCON_ENSCK,
+ hw->regs + S3C2410_SPCON);
hw->set_cs(hw->pdata, spi->chip_select, cspol);
-
break;
}
}
-static int s3c24xx_spi_setupxfer(struct spi_device *spi,
- struct spi_transfer *t)
+static int s3c24xx_spi_update_state(struct spi_device *spi,
+ struct spi_transfer *t)
{
struct s3c24xx_spi *hw = to_hw(spi);
+ struct s3c24xx_spi_devstate *cs = spi->controller_state;
unsigned int bpw;
unsigned int hz;
unsigned int div;
@@ -127,41 +126,89 @@ static int s3c24xx_spi_setupxfer(struct spi_device *spi,
return -EINVAL;
}
- clk = clk_get_rate(hw->clk);
- div = DIV_ROUND_UP(clk, hz * 2) - 1;
+ if (spi->mode != cs->mode) {
+ u8 spcon = SPCON_DEFAULT;
- if (div > 255)
- div = 255;
+ if (spi->mode & SPI_CPHA)
+ spcon |= S3C2410_SPCON_CPHA_FMTB;
- dev_dbg(&spi->dev, "setting pre-scaler to %d (wanted %d, got %ld)\n",
- div, hz, clk / (2 * (div + 1)));
+ if (spi->mode & SPI_CPOL)
+ spcon |= S3C2410_SPCON_CPOL_HIGH;
+ cs->mode = spi->mode;
+ cs->spcon = spcon;
+ }
- writeb(div, hw->regs + S3C2410_SPPRE);
+ if (cs->hz != hz) {
+ clk = clk_get_rate(hw->clk);
+ div = DIV_ROUND_UP(clk, hz * 2) - 1;
- spin_lock(&hw->bitbang.lock);
- if (!hw->bitbang.busy) {
- hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
- /* need to ndelay for 0.5 clocktick ? */
+ if (div > 255)
+ div = 255;
+
+ dev_dbg(&spi->dev, "pre-scaler=%d (wanted %d, got %ld)\n",
+ div, hz, clk / (2 * (div + 1)));
+
+ cs->hz = hz;
+ cs->sppre = div;
}
- spin_unlock(&hw->bitbang.lock);
return 0;
}
+static int s3c24xx_spi_setupxfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct s3c24xx_spi_devstate *cs = spi->controller_state;
+ struct s3c24xx_spi *hw = to_hw(spi);
+ int ret;
+
+ ret = s3c24xx_spi_update_state(spi, t);
+ if (!ret)
+ writeb(cs->sppre, hw->regs + S3C2410_SPPRE);
+
+ return ret;
+}
+
static int s3c24xx_spi_setup(struct spi_device *spi)
{
+ struct s3c24xx_spi_devstate *cs = spi->controller_state;
+ struct s3c24xx_spi *hw = to_hw(spi);
int ret;
- ret = s3c24xx_spi_setupxfer(spi, NULL);
- if (ret < 0) {
- dev_err(&spi->dev, "setupxfer returned %d\n", ret);
+ /* allocate settings on the first call */
+ if (!cs) {
+ cs = kzalloc(sizeof(struct s3c24xx_spi_devstate), GFP_KERNEL);
+ if (!cs) {
+ dev_err(&spi->dev, "no memory for controller state\n");
+ return -ENOMEM;
+ }
+
+ cs->spcon = SPCON_DEFAULT;
+ cs->hz = -1;
+ spi->controller_state = cs;
+ }
+
+ /* initialise the state from the device */
+ ret = s3c24xx_spi_update_state(spi, NULL);
+ if (ret)
return ret;
+
+ spin_lock(&hw->bitbang.lock);
+ if (!hw->bitbang.busy) {
+ hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
+ /* need to ndelay for 0.5 clocktick ? */
}
+ spin_unlock(&hw->bitbang.lock);
return 0;
}
+static void s3c24xx_spi_cleanup(struct spi_device *spi)
+{
+ kfree(spi->controller_state);
+}
+
static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count)
{
return hw->tx ? hw->tx[count] : 0;
@@ -289,7 +336,9 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev)
hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
hw->bitbang.chipselect = s3c24xx_spi_chipsel;
hw->bitbang.txrx_bufs = s3c24xx_spi_txrx;
- hw->bitbang.master->setup = s3c24xx_spi_setup;
+
+ hw->master->setup = s3c24xx_spi_setup;
+ hw->master->cleanup = s3c24xx_spi_cleanup;
dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
@@ -302,7 +351,7 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev)
goto err_no_iores;
}
- hw->ioarea = request_mem_region(res->start, (res->end - res->start)+1,
+ hw->ioarea = request_mem_region(res->start, resource_size(res),
pdev->name);
if (hw->ioarea == NULL) {
@@ -311,7 +360,7 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev)
goto err_no_iores;
}
- hw->regs = ioremap(res->start, (res->end - res->start)+1);
+ hw->regs = ioremap(res->start, resource_size(res));
if (hw->regs == NULL) {
dev_err(&pdev->dev, "Cannot map IO\n");
err = -ENXIO;
@@ -388,7 +437,7 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev)
err_no_iores:
err_no_pdata:
- spi_master_put(hw->master);;
+ spi_master_put(hw->master);
err_nomem:
return err;
@@ -421,9 +470,9 @@ static int __exit s3c24xx_spi_remove(struct platform_device *dev)
#ifdef CONFIG_PM
-static int s3c24xx_spi_suspend(struct platform_device *pdev, pm_message_t msg)
+static int s3c24xx_spi_suspend(struct device *dev)
{
- struct s3c24xx_spi *hw = platform_get_drvdata(pdev);
+ struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
if (hw->pdata && hw->pdata->gpio_setup)
hw->pdata->gpio_setup(hw->pdata, 0);
@@ -432,27 +481,31 @@ static int s3c24xx_spi_suspend(struct platform_device *pdev, pm_message_t msg)
return 0;
}
-static int s3c24xx_spi_resume(struct platform_device *pdev)
+static int s3c24xx_spi_resume(struct device *dev)
{
- struct s3c24xx_spi *hw = platform_get_drvdata(pdev);
+ struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
s3c24xx_spi_initialsetup(hw);
return 0;
}
+static struct dev_pm_ops s3c24xx_spi_pmops = {
+ .suspend = s3c24xx_spi_suspend,
+ .resume = s3c24xx_spi_resume,
+};
+
+#define S3C24XX_SPI_PMOPS &s3c24xx_spi_pmops
#else
-#define s3c24xx_spi_suspend NULL
-#define s3c24xx_spi_resume NULL
-#endif
+#define S3C24XX_SPI_PMOPS NULL
+#endif /* CONFIG_PM */
MODULE_ALIAS("platform:s3c2410-spi");
static struct platform_driver s3c24xx_spi_driver = {
.remove = __exit_p(s3c24xx_spi_remove),
- .suspend = s3c24xx_spi_suspend,
- .resume = s3c24xx_spi_resume,
.driver = {
.name = "s3c2410-spi",
.owner = THIS_MODULE,
+ .pm = S3C24XX_SPI_PMOPS,
},
};
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.