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authorSascha Hauer <s.hauer@pengutronix.de>2012-08-28 11:39:25 +0200
committerThierry Reding <thierry.reding@avionic-design.de>2012-09-12 14:25:05 +0200
commit66ad6a613abeeeabc5217a0498fae63205e8ddb8 (patch)
tree10990eefe667348983b32b0894a94cdbb7b1ba26 /drivers/pwm
parent140827c148f2f3a95fdcec5310f6cd980139b383 (diff)
downloadlinux-66ad6a613abeeeabc5217a0498fae63205e8ddb8.tar.bz2
pwm: i.MX: add functions to enable/disable pwm.
We used to enable/disable the PWM only by switching the clock on or off. Instead, use the dedicated register bits. These differ on different SoCs, so introduce a SoC specific function for this. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-imx.c48
1 files changed, 44 insertions, 4 deletions
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 5d426ffe6a31..13d4d22f12cf 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -25,6 +25,7 @@
#define MX1_PWMS 0x04 /* PWM Sample Register */
#define MX1_PWMP 0x08 /* PWM Period Register */
+#define MX1_PWMC_EN (1 << 4)
/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */
@@ -49,6 +50,7 @@ struct imx_chip {
int (*config)(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns);
+ void (*set_enable)(struct pwm_chip *chip, bool enable);
};
#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip)
@@ -82,6 +84,21 @@ static int imx_pwm_config_v1(struct pwm_chip *chip,
return 0;
}
+static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ u32 val;
+
+ val = readl(imx->mmio_base + MX1_PWMC);
+
+ if (enable)
+ val |= MX1_PWMC_EN;
+ else
+ val &= ~MX1_PWMC_EN;
+
+ writel(val, imx->mmio_base + MX1_PWMC);
+}
+
static int imx_pwm_config_v2(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
{
@@ -116,7 +133,10 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
cr = MX3_PWMCR_PRESCALER(prescale) |
MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
- MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
+ MX3_PWMCR_DBGEN;
+
+ if (imx->enabled)
+ cr |= MX3_PWMCR_EN;
if (cpu_is_mx25())
cr |= MX3_PWMCR_CLKSRC_IPG;
@@ -128,6 +148,21 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
return 0;
}
+static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ u32 val;
+
+ val = readl(imx->mmio_base + MX3_PWMCR);
+
+ if (enable)
+ val |= MX3_PWMCR_EN;
+ else
+ val &= ~MX3_PWMCR_EN;
+
+ writel(val, imx->mmio_base + MX3_PWMCR);
+}
+
static int imx_pwm_config(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
{
@@ -145,6 +180,8 @@ static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
if (ret)
return ret;
+ imx->set_enable(chip, true);
+
imx->enabled = 1;
return 0;
@@ -154,7 +191,7 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
- writel(0, imx->mmio_base + MX3_PWMCR);
+ imx->set_enable(chip, false);
clk_disable_unprepare(imx->clk);
imx->enabled = 0;
@@ -199,10 +236,13 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
if (imx->mmio_base == NULL)
return -EADDRNOTAVAIL;
- if (cpu_is_mx1() || cpu_is_mx21())
+ if (cpu_is_mx1() || cpu_is_mx21()) {
imx->config = imx_pwm_config_v1;
- else
+ imx->set_enable = imx_pwm_set_enable_v1;
+ } else {
imx->config = imx_pwm_config_v2;
+ imx->set_enable = imx_pwm_set_enable_v2;
+ }
ret = pwmchip_add(&imx->chip);
if (ret < 0)