Re: [PATCH v4 2/2] pwm: rockchip: Added to support for RK3288 SoC

caesar <caesar.wang@xxxxxxxxxxxxxx> · Thu, 07 Aug 2014 21:04:30 +0800

Thierry,

在 2014年08月07日 14:18, Thierry Reding 写道:
On Thu, Jul 24, 2014 at 06:21:35PM +0800, Caesar Wang wrote:
This patch added to support the PWM controller found on
RK3288 SoC.

Signed-off-by: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx>
---
  drivers/pwm/pwm-rockchip.c | 124 ++++++++++++++++++++++++++++++++++++++-------
  1 file changed, 105 insertions(+), 19 deletions(-)

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index eec2145..59c2513 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -2,6 +2,7 @@
   * PWM driver for Rockchip SoCs
   *
   * Copyright (C) 2014 Beniamino Galvani <b.galvani@xxxxxxxxx>
+ * Copyright (C) 2014 ROCKCHIP, Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
@@ -12,6 +13,7 @@
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/of.h>
+#include <linux/of_device.h>
  #include <linux/platform_device.h>
  #include <linux/pwm.h>
  #include <linux/time.h>
@@ -25,17 +27,72 @@
  
  #define PRESCALER		2
  
+#define PWM_ENABLE		(1 << 0)
+#define PWM_CONTINUOUS		(1 << 1)
+#define PWM_DUTY_POSITIVE	(1 << 3)
+#define PWM_INACTIVE_NEGATIVE	(0 << 4)
+#define PWM_OUTPUT_LEFT		(0 << 5)
+#define PWM_LP_DISABLE		(0 << 8)
+
  struct rockchip_pwm_chip {
  	struct pwm_chip chip;
  	struct clk *clk;
+	const struct rockchip_pwm_data *data;
  	void __iomem *base;
  };
  
+struct rockchip_pwm_regs {
+	unsigned long duty;
+	unsigned long period;
+	unsigned long cntr;
+	unsigned long ctrl;
+};
+
+struct rockchip_pwm_data {
+	struct rockchip_pwm_regs regs;
+	unsigned int prescaler;
+
+	void (*set_enable)(struct pwm_chip *chip, bool enable);
+};
+
  static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c)
  {
  	return container_of(c, struct rockchip_pwm_chip, chip);
  }
  
+static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 val = 0;
+	u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
+
+	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+	if (enable)
+		val |= enable_conf;
+	else
+		val &= ~enable_conf;
+
+	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
+static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	u32 val = 0;
+	u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
+		PWM_CONTINUOUS | PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
+
+	val = readl_relaxed(pc->base + pc->data->regs.ctrl);
+
+	if (enable)
+		val |= enable_conf;
+	else
+		val &= ~enable_conf;
+
+	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
+}
+
  static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  			       int duty_ns, int period_ns)
  {
@@ -52,20 +109,20 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
  	 * default prescaler value for all practical clock rate values.
  	 */
  	div = clk_rate * period_ns;
-	do_div(div, PRESCALER * NSEC_PER_SEC);
+	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
  	period = div;
  
  	div = clk_rate * duty_ns;
-	do_div(div, PRESCALER * NSEC_PER_SEC);
+	do_div(div, pc->data->prescaler * NSEC_PER_SEC);
  	duty = div;
  
  	ret = clk_enable(pc->clk);
  	if (ret)
  		return ret;
  
-	writel(period, pc->base + PWM_LRC);
-	writel(duty, pc->base + PWM_HRC);
-	writel(0, pc->base + PWM_CNTR);
+	writel(period, pc->base + pc->data->regs.period);
+	writel(duty, pc->base + pc->data->regs.duty);
+	writel(0, pc->base + pc->data->regs.cntr);
  
  	clk_disable(pc->clk);
  
@@ -76,15 +133,12 @@ static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
  	int ret;
-	u32 val;
  
  	ret = clk_enable(pc->clk);
  	if (ret)
  		return ret;
  
-	val = readl_relaxed(pc->base + PWM_CTRL);
-	val |= PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
-	writel_relaxed(val, pc->base + PWM_CTRL);
+	pc->data->set_enable(chip, true);
  
  	return 0;
  }
@@ -92,11 +146,8 @@ static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
  static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
  {
  	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
-	u32 val;
  
-	val = readl_relaxed(pc->base + PWM_CTRL);
-	val &= ~(PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN);
-	writel_relaxed(val, pc->base + PWM_CTRL);
+	pc->data->set_enable(chip, false);
  
  	clk_disable(pc->clk);
  }
@@ -108,12 +159,52 @@ static const struct pwm_ops rockchip_pwm_ops = {
  	.owner = THIS_MODULE,
  };
  
+static const struct rockchip_pwm_data pwm_data_v1 = {
+	.regs.duty = PWM_HRC,
+	.regs.period = PWM_LRC,
+	.regs.cntr = PWM_CNTR,
+	.regs.ctrl = PWM_CTRL,
Perhaps a slightly more idiomatic way to write this would be:

	static const struct rockchip_pwm_data pwm_data_v1 = {
		.regs = {
			.duty = PWM_HRC,
			.period = PWM_LRC,
			.cntr = PWM_CNTR,
			.ctrl = PWM_CTRL,
		},
		...
	};

And similar for the v2 and vop structures. And like I said in another
reply, since the defines are now only used in this structure it's a
little redundant to give them symbolic names, so the above could equally
well be:

	static const struct rockchip_pwm_data pwm_data_v1 = {
		.regs = {
			.duty = 0x04,
			.period = 0x08,
			.cntr = 0x00,
			.ctrl = 0x0c,
		},
		...
	};

+	.prescaler = PRESCALER,
Similarly for the prescaler value, it can now simply be 2 here.

+	.set_enable = rockchip_pwm_set_enable_v1,
+};
+
+static const struct rockchip_pwm_data pwm_data_v2 = {
+	.regs.duty = PWM_LRC,
+	.regs.period = PWM_HRC,
+	.regs.cntr = PWM_CNTR,
+	.regs.ctrl = PWM_CTRL,
+	.prescaler = PRESCALER-1,
And 1 here.

+	.set_enable = rockchip_pwm_set_enable_v2,
+};
+
+static const struct rockchip_pwm_data pwm_data_vop = {
+	.regs.duty = PWM_LRC,
+	.regs.period = PWM_HRC,
+	.regs.cntr = PWM_CTRL,
+	.regs.ctrl = PWM_CNTR,
+	.prescaler = PRESCALER-1,
And 1 here.

As you say, I will rewrite the about if it's really need  do so it.
For example:

static const struct rockchip_pwm_data pwm_data_v1 = {
    .regs = {
                .duty = 0x04,
                .period = 0x08,
                .cntr = 0x00,
                .ctrl = 0x0c,
    },
    .prescaler = 2,
    .set_enable = rockchip_pwm_set_enable_v1,
};

static const struct rockchip_pwm_data pwm_data_v2 = {
    .regs = {
                .duty = 0x08,
                .period = 0x04,
                .cntr = 0x00,
                .ctrl = 0x0c,
    },
    .prescaler = 1,
    .set_enable = rockchip_pwm_set_enable_v2,
};

static const struct rockchip_pwm_data pwm_data_vop = {
    .regs = {
                .duty = 0x08,
                .period = 0x04,
                .cntr = 0x0c,
                .ctrl = 0x00,
    },
    .prescaler = 1,
    .set_enable = rockchip_pwm_set_enable_v2,
};

Is that right?

+	.set_enable = rockchip_pwm_set_enable_v2,
+};
No need for the double indirection.

Sorry, I think is need if you mean a double indirection for ".set_enable".



Caesar

Thierry


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