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Subject[PATCH v2 2/2] Enable Stop_enable mode during configuration of pwm.
Date
From
From: Samir Hachimi <shachimi@adeneo-embedded.com>

Enable Stop_enable mode during configuration of pwm.
Check architecture by looking in driver_data instead of cpu_is_xxx.

Signed-off-by: Samir Hachimi <shachimi@adeneo-embedded.com>
---
drivers/pwm/pwm-imx.c | 59 +++++++++++++++++++++++++++++++++++-------------
1 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 0519bf2..7df919f 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -32,6 +32,7 @@
#define MX3_PWMSAR 0x0C /* PWM Sample Register */
#define MX3_PWMPR 0x10 /* PWM Period Register */
#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)
+#define MX3_PWMCR_STOPEN (1 << 25)
#define MX3_PWMCR_DOZEEN (1 << 24)
#define MX3_PWMCR_WAITEN (1 << 23)
#define MX3_PWMCR_DBGEN (1 << 22)
@@ -39,6 +40,16 @@
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
#define MX3_PWMCR_EN (1 << 0)

+/* Use the platform_id to distinguish different Archs. */
+#define IS_MX1 0x0
+#define IS_MX21 0x1
+#define IS_MX25 0x2
+#define IS_MX6Q 0x3
+#define PWM_IS_MX1(x) ((x)->id_entry->driver_data == IS_MX1)
+#define PWM_IS_MX21(x) ((x)->id_entry->driver_data == IS_MX21)
+#define PWM_IS_MX25(x) ((x)->id_entry->driver_data == IS_MX25)
+#define PWM_IS_MX6Q(x) ((x)->id_entry->driver_data == IS_MX6Q)
+
struct imx_chip {
struct clk *clk;

@@ -46,6 +57,7 @@ struct imx_chip {
void __iomem *mmio_base;

struct pwm_chip chip;
+ struct platform_device *pdev;
};

#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip)
@@ -65,7 +77,7 @@ static int imx_pwm_config(struct pwm_chip *chip,
return rc;
}

- if (!(cpu_is_mx1() || cpu_is_mx21())) {
+ if (!(PWM_IS_MX1(imx->pdev) || PWM_IS_MX21(imx->pdev))) {
unsigned long long c;
unsigned long period_cycles, duty_cycles, prescale;
u32 cr;
@@ -78,36 +90,33 @@ static int imx_pwm_config(struct pwm_chip *chip,
prescale = period_cycles / 0x10000 + 1;

period_cycles /= prescale;
- c = (unsigned long long)period_cycles * duty_ns;
- do_div(c, period_ns);
- duty_cycles = c;

- /*
- * according to imx pwm RM, the real period value should be
- * PERIOD value in PWMPR plus 2.
+ /* the chip documentation says the counter counts up to
+ * period_cycles + 1 and then is reset to 0, so the
+ * actual period of the PWM wave is period_cycles + 2
*/
- if (period_cycles > 2)
- period_cycles -= 2;
- else
- period_cycles = 0;
+ c = (unsigned long long)(period_cycles + 2) * duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;

writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
writel(period_cycles, imx->mmio_base + MX3_PWMPR);

cr = MX3_PWMCR_PRESCALER(prescale) |
- MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | MX3_PWMCR_DBGEN;
+ MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+ MX3_PWMCR_DBGEN | MX3_PWMCR_STOPEN;

/* If the PWM is enabled, keep it so. */
if (imx->clk_enabled)
cr |= MX3_PWMCR_EN;

- if (cpu_is_mx25())
+ if (PWM_IS_MX25(imx->pdev))
cr |= MX3_PWMCR_CLKSRC_IPG;
else
cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;

writel(cr, imx->mmio_base + MX3_PWMCR);
- } else if (cpu_is_mx1() || cpu_is_mx21()) {
+ } else if (PWM_IS_MX1(imx->pdev) || PWM_IS_MX21(imx->pdev)) {
/* The PWM subsystem allows for exact frequencies. However,
* I cannot connect a scope on my device to the PWM line and
* thus cannot provide the program the PWM controller
@@ -150,7 +159,7 @@ static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
if (rc)
return rc;

- if (!(cpu_is_mx1() || cpu_is_mx21())) {
+ if (!(PWM_IS_MX1(imx->pdev) || PWM_IS_MX21(imx->pdev))) {
u32 cr = readl(imx->mmio_base + MX3_PWMCR);
cr |= MX3_PWMCR_EN;
writel(cr, imx->mmio_base + MX3_PWMCR);
@@ -167,7 +176,7 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
if (!imx->clk_enabled)
return;

- if (!(cpu_is_mx1() || cpu_is_mx21())) {
+ if (!(PWM_IS_MX1(imx->pdev) || PWM_IS_MX21(imx->pdev))) {
u32 cr = readl(imx->mmio_base + MX3_PWMCR);
cr &= ~MX3_PWMCR_EN;
writel(cr, imx->mmio_base + MX3_PWMCR);
@@ -207,6 +216,7 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
imx->chip.npwm = 1;

imx->clk_enabled = 0;
+ imx->pdev = pdev;

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
@@ -237,9 +247,26 @@ static int __devexit imx_pwm_remove(struct platform_device *pdev)
return pwmchip_remove(&imx->chip);
}

+static const struct platform_device_id pwm_ids[] = {
+ { .name = "imx1-pwm", .driver_data = IS_MX1, },
+ { .name = "imx21-pwm", .driver_data = IS_MX21, },
+ { .name = "imx25-pwm", .driver_data = IS_MX25, },
+ { .name = "imx6q-pwm", .driver_data = IS_MX6Q, },
+ {},
+};
+
+static const struct of_device_id mxc_pwm_dt_ids[] = {
+ {
+ .compatible = "fsl,imx6q-pwm",
+ .data = (void *)&pwm_ids[IS_MX6Q]
+ },
+ { /* sentinel */ }
+};
+
static struct platform_driver imx_pwm_driver = {
.driver = {
.name = "mxc_pwm",
+ .of_match_table = of_match_ptr(mxc_pwm_dt_ids),
},
.probe = imx_pwm_probe,
.remove = __devexit_p(imx_pwm_remove),
--
1.7.1

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