[PATCH v4 2/2] pwm: rockchip: Added to support for RK3288 SoC
caesar
caesar.wang at rock-chips.com
Thu Aug 7 06:04:30 PDT 2014
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 at rock-chips.com>
>> ---
>> 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 at gmail.com>
>> + * 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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