diff mbox

[2/3] pwm: ftm-pwm: Convert to direct regmap API usage.

Message ID 1395377590-23537-3-git-send-email-Li.Xiubo@freescale.com
State Rejected
Headers show

Commit Message

Xiubo Li March 21, 2014, 4:53 a.m. UTC 
Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
---
 drivers/pwm/pwm-fsl-ftm.c | 83 +++++++++++++++++++++++++----------------------
 1 file changed, 44 insertions(+), 39 deletions(-)

Comments

Thierry Reding April 28, 2014, 2:59 p.m. UTC | #1 
On Fri, Mar 21, 2014 at 12:53:09PM +0800, Xiubo Li wrote:
> Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
> ---
>  drivers/pwm/pwm-fsl-ftm.c | 83 +++++++++++++++++++++++++----------------------
>  1 file changed, 44 insertions(+), 39 deletions(-)

This could explain the advantages of converting to regmap. Looking at
this diffstat above, it's not immediately obvious that there's an
advantage because you end up adding 5 lines.

Again I'm guessing this is in preparation to add endianess support, and
it will be really easy to add that using regmap, so the gains will only
become obvious later on.

That's the kind of thing I'd like to see in the patch description. It
tells me why this patch makes sense.

Thierry
Xiubo Li April 28, 2014, 3:14 p.m. UTC | #2 
> >  drivers/pwm/pwm-fsl-ftm.c | 83 +++++++++++++++++++++++++----------------------
> >  1 file changed, 44 insertions(+), 39 deletions(-)
> 
> This could explain the advantages of converting to regmap. Looking at
> this diffstat above, it's not immediately obvious that there's an
> advantage because you end up adding 5 lines.
> 
> Again I'm guessing this is in preparation to add endianess support, and
> it will be really easy to add that using regmap, so the gains will only
> become obvious later on.
> 
> That's the kind of thing I'd like to see in the patch description. It
> tells me why this patch makes sense.
> 

Yes, That`s why converting to use the regmap.

I`ll update this as you have mentioned.

Thanks,
BRs
Xiubo
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diff mbox

Patch

diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
index 4a4ad58..5d999c1 100644
--- a/drivers/pwm/pwm-fsl-ftm.c
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -18,6 +18,7 @@ 
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 
 #define FTM_SC		0x00
@@ -82,7 +83,7 @@  struct fsl_pwm_chip {
 	unsigned int cnt_select;
 	unsigned int clk_ps;
 
-	void __iomem *base;
+	struct regmap *regmap;
 
 	int period_ns;
 
@@ -218,10 +219,11 @@  static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
 					    unsigned long period_ns,
 					    unsigned long duty_ns)
 {
-	unsigned long long val, duty;
+	unsigned long long duty;
+	u32 val;
 
-	val = readl(fpc->base + FTM_MOD);
-	duty = duty_ns * (val + 1);
+	regmap_read(fpc->regmap, FTM_MOD, &val);
+	duty = (unsigned long long)duty_ns * (val + 1);
 	do_div(duty, period_ns);
 
 	return (unsigned long)duty;
@@ -231,7 +233,7 @@  static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			  int duty_ns, int period_ns)
 {
 	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
-	u32 val, period, duty;
+	u32 period, duty;
 
 	mutex_lock(&fpc->lock);
 
@@ -256,11 +258,9 @@  static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			return -EINVAL;
 		}
 
-		val = readl(fpc->base + FTM_SC);
-		val &= ~FTM_SC_PS_MASK;
-		val |= fpc->clk_ps;
-		writel(val, fpc->base + FTM_SC);
-		writel(period - 1, fpc->base + FTM_MOD);
+		regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
+				   fpc->clk_ps);
+		regmap_write(fpc->regmap, FTM_MOD, period - 1);
 
 		fpc->period_ns = period_ns;
 	}
@@ -269,8 +269,9 @@  static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
 
-	writel(FTM_CSC_MSB | FTM_CSC_ELSB, fpc->base + FTM_CSC(pwm->hwpwm));
-	writel(duty, fpc->base + FTM_CV(pwm->hwpwm));
+	regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
+		     FTM_CSC_MSB | FTM_CSC_ELSB);
+	regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
 
 	return 0;
 }
@@ -282,31 +283,28 @@  static int fsl_pwm_set_polarity(struct pwm_chip *chip,
 	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 	u32 val;
 
-	val = readl(fpc->base + FTM_POL);
+	regmap_read(fpc->regmap, FTM_POL, &val);
 
 	if (polarity == PWM_POLARITY_INVERSED)
 		val |= BIT(pwm->hwpwm);
 	else
 		val &= ~BIT(pwm->hwpwm);
 
-	writel(val, fpc->base + FTM_POL);
+	regmap_write(fpc->regmap, FTM_POL, val);
 
 	return 0;
 }
 
 static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
 {
-	u32 val;
 	int ret;
 
 	if (fpc->use_count != 0)
 		return 0;
 
 	/* select counter clock source */
-	val = readl(fpc->base + FTM_SC);
-	val &= ~FTM_SC_CLK_MASK;
-	val |= FTM_SC_CLK(fpc->cnt_select);
-	writel(val, fpc->base + FTM_SC);
+	regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
+			   FTM_SC_CLK(fpc->cnt_select));
 
 	ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
 	if (ret)
@@ -326,13 +324,10 @@  static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
 static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
-	u32 val;
 	int ret;
 
 	mutex_lock(&fpc->lock);
-	val = readl(fpc->base + FTM_OUTMASK);
-	val &= ~BIT(pwm->hwpwm);
-	writel(val, fpc->base + FTM_OUTMASK);
+	regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
 
 	ret = fsl_counter_clock_enable(fpc);
 	mutex_unlock(&fpc->lock);
@@ -342,8 +337,6 @@  static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 
 static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
 {
-	u32 val;
-
 	/*
 	 * already disabled, do nothing
 	 */
@@ -355,9 +348,7 @@  static void fsl_counter_clock_disable(struct fsl_pwm_chip *fpc)
 		return;
 
 	/* no users left, disable PWM counter clock */
-	val = readl(fpc->base + FTM_SC);
-	val &= ~FTM_SC_CLK_MASK;
-	writel(val, fpc->base + FTM_SC);
+	regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK, 0);
 
 	clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
 	clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
@@ -369,14 +360,12 @@  static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 	u32 val;
 
 	mutex_lock(&fpc->lock);
-	val = readl(fpc->base + FTM_OUTMASK);
-	val |= BIT(pwm->hwpwm);
-	writel(val, fpc->base + FTM_OUTMASK);
+	regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
+			   BIT(pwm->hwpwm));
 
 	fsl_counter_clock_disable(fpc);
 
-	val = readl(fpc->base + FTM_OUTMASK);
-
+	regmap_read(fpc->regmap, FTM_OUTMASK, &val);
 	if ((val & 0xFF) == 0xFF)
 		fpc->period_ns = 0;
 
@@ -401,19 +390,28 @@  static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
 	if (ret)
 		return ret;
 
-	writel(0x00, fpc->base + FTM_CNTIN);
-	writel(0x00, fpc->base + FTM_OUTINIT);
-	writel(0xFF, fpc->base + FTM_OUTMASK);
+	regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
+	regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
+	regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
 
 	clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
 
 	return 0;
 }
 
+static struct regmap_config fsl_pwm_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+
+	.max_register = FTM_PWMLOAD,
+};
+
 static int fsl_pwm_probe(struct platform_device *pdev)
 {
 	struct fsl_pwm_chip *fpc;
 	struct resource *res;
+	void __iomem *base;
 	int ret;
 
 	fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
@@ -425,9 +423,16 @@  static int fsl_pwm_probe(struct platform_device *pdev)
 	fpc->chip.dev = &pdev->dev;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	fpc->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(fpc->base))
-		return PTR_ERR(fpc->base);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
+						&fsl_pwm_regmap_config);
+	if (IS_ERR(fpc->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(fpc->regmap);
+	}
 
 	fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
 	if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {