blob: 3b8da7b0091b129ff40a6563cc89c655b19af7ae [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* PWM driver for Rockchip SoCs
*
* Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
* Copyright (C) 2014 ROCKCHIP, Inc.
*/
#include <linux/clk.h>
#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>
#define PWM_CTRL_TIMER_EN (1 << 0)
#define PWM_CTRL_OUTPUT_EN (1 << 3)
#define PWM_ENABLE (1 << 0)
#define PWM_CONTINUOUS (1 << 1)
#define PWM_DUTY_POSITIVE (1 << 3)
#define PWM_DUTY_NEGATIVE (0 << 3)
#define PWM_INACTIVE_NEGATIVE (0 << 4)
#define PWM_INACTIVE_POSITIVE (1 << 4)
#define PWM_POLARITY_MASK (PWM_DUTY_POSITIVE | PWM_INACTIVE_POSITIVE)
#define PWM_OUTPUT_LEFT (0 << 5)
#define PWM_LOCK_EN (1 << 6)
#define PWM_LP_DISABLE (0 << 8)
struct rockchip_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
struct clk *pclk;
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;
bool supports_polarity;
bool supports_lock;
u32 enable_conf;
};
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_get_state(struct pwm_chip *chip,
struct pwm_device *pwm,
struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
unsigned long clk_rate;
u64 tmp;
u32 val;
int ret;
ret = clk_enable(pc->pclk);
if (ret)
return;
clk_rate = clk_get_rate(pc->clk);
tmp = readl_relaxed(pc->base + pc->data->regs.period);
tmp *= pc->data->prescaler * NSEC_PER_SEC;
state->period = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
tmp = readl_relaxed(pc->base + pc->data->regs.duty);
tmp *= pc->data->prescaler * NSEC_PER_SEC;
state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, clk_rate);
val = readl_relaxed(pc->base + pc->data->regs.ctrl);
state->enabled = (val & enable_conf) == enable_conf;
if (pc->data->supports_polarity && !(val & PWM_DUTY_POSITIVE))
state->polarity = PWM_POLARITY_INVERSED;
else
state->polarity = PWM_POLARITY_NORMAL;
clk_disable(pc->pclk);
}
static void rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
unsigned long period, duty;
u64 clk_rate, div;
u32 ctrl;
clk_rate = clk_get_rate(pc->clk);
/*
* Since period and duty cycle registers have a width of 32
* bits, every possible input period can be obtained using the
* default prescaler value for all practical clock rate values.
*/
div = clk_rate * state->period;
period = DIV_ROUND_CLOSEST_ULL(div,
pc->data->prescaler * NSEC_PER_SEC);
div = clk_rate * state->duty_cycle;
duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC);
/*
* Lock the period and duty of previous configuration, then
* change the duty and period, that would not be effective.
*/
ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
if (pc->data->supports_lock) {
ctrl |= PWM_LOCK_EN;
writel_relaxed(ctrl, pc->base + pc->data->regs.ctrl);
}
writel(period, pc->base + pc->data->regs.period);
writel(duty, pc->base + pc->data->regs.duty);
if (pc->data->supports_polarity) {
ctrl &= ~PWM_POLARITY_MASK;
if (state->polarity == PWM_POLARITY_INVERSED)
ctrl |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
else
ctrl |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
}
/*
* Unlock and set polarity at the same time,
* the configuration of duty, period and polarity
* would be effective together at next period.
*/
if (pc->data->supports_lock)
ctrl &= ~PWM_LOCK_EN;
writel(ctrl, pc->base + pc->data->regs.ctrl);
}
static int rockchip_pwm_enable(struct pwm_chip *chip,
struct pwm_device *pwm,
bool enable)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
int ret;
u32 val;
if (enable) {
ret = clk_enable(pc->clk);
if (ret)
return ret;
}
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);
if (!enable)
clk_disable(pc->clk);
return 0;
}
static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
struct pwm_state curstate;
bool enabled;
int ret = 0;
ret = clk_enable(pc->pclk);
if (ret)
return ret;
pwm_get_state(pwm, &curstate);
enabled = curstate.enabled;
if (state->polarity != curstate.polarity && enabled &&
!pc->data->supports_lock) {
ret = rockchip_pwm_enable(chip, pwm, false);
if (ret)
goto out;
enabled = false;
}
rockchip_pwm_config(chip, pwm, state);
if (state->enabled != enabled) {
ret = rockchip_pwm_enable(chip, pwm, state->enabled);
if (ret)
goto out;
}
out:
clk_disable(pc->pclk);
return ret;
}
static const struct pwm_ops rockchip_pwm_ops = {
.get_state = rockchip_pwm_get_state,
.apply = rockchip_pwm_apply,
.owner = THIS_MODULE,
};
static const struct rockchip_pwm_data pwm_data_v1 = {
.regs = {
.duty = 0x04,
.period = 0x08,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 2,
.supports_polarity = false,
.supports_lock = false,
.enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN,
};
static const struct rockchip_pwm_data pwm_data_v2 = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = false,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct rockchip_pwm_data pwm_data_vop = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x0c,
.ctrl = 0x00,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = false,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct rockchip_pwm_data pwm_data_v3 = {
.regs = {
.duty = 0x08,
.period = 0x04,
.cntr = 0x00,
.ctrl = 0x0c,
},
.prescaler = 1,
.supports_polarity = true,
.supports_lock = true,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
};
static const struct of_device_id rockchip_pwm_dt_ids[] = {
{ .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1},
{ .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2},
{ .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop},
{ .compatible = "rockchip,rk3328-pwm", .data = &pwm_data_v3},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
static int rockchip_pwm_probe(struct platform_device *pdev)
{
const struct of_device_id *id;
struct rockchip_pwm_chip *pc;
struct resource *r;
u32 enable_conf, ctrl;
bool enabled;
int ret, count;
id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev);
if (!id)
return -EINVAL;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
return -ENOMEM;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pc->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(pc->base))
return PTR_ERR(pc->base);
pc->clk = devm_clk_get(&pdev->dev, "pwm");
if (IS_ERR(pc->clk)) {
pc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pc->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),
"Can't get bus clk\n");
}
count = of_count_phandle_with_args(pdev->dev.of_node,
"clocks", "#clock-cells");
if (count == 2)
pc->pclk = devm_clk_get(&pdev->dev, "pclk");
else
pc->pclk = pc->clk;
if (IS_ERR(pc->pclk)) {
ret = PTR_ERR(pc->pclk);
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev, "Can't get APB clk: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(pc->clk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare enable bus clk: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(pc->pclk);
if (ret) {
dev_err(&pdev->dev, "Can't prepare enable APB clk: %d\n", ret);
goto err_clk;
}
platform_set_drvdata(pdev, pc);
pc->data = id->data;
pc->chip.dev = &pdev->dev;
pc->chip.ops = &rockchip_pwm_ops;
pc->chip.base = -1;
pc->chip.npwm = 1;
if (pc->data->supports_polarity) {
pc->chip.of_xlate = of_pwm_xlate_with_flags;
pc->chip.of_pwm_n_cells = 3;
}
enable_conf = pc->data->enable_conf;
ctrl = readl_relaxed(pc->base + pc->data->regs.ctrl);
enabled = (ctrl & enable_conf) == enable_conf;
ret = pwmchip_add(&pc->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
goto err_pclk;
}
/* Keep the PWM clk enabled if the PWM appears to be up and running. */
if (!enabled)
clk_disable(pc->clk);
clk_disable(pc->pclk);
return 0;
err_pclk:
clk_disable_unprepare(pc->pclk);
err_clk:
clk_disable_unprepare(pc->clk);
return ret;
}
static int rockchip_pwm_remove(struct platform_device *pdev)
{
struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
/*
* Disable the PWM clk before unpreparing it if the PWM device is still
* running. This should only happen when the last PWM user left it
* enabled, or when nobody requested a PWM that was previously enabled
* by the bootloader.
*
* FIXME: Maybe the core should disable all PWM devices in
* pwmchip_remove(). In this case we'd only have to call
* clk_unprepare() after pwmchip_remove().
*
*/
if (pwm_is_enabled(pc->chip.pwms))
clk_disable(pc->clk);
clk_unprepare(pc->pclk);
clk_unprepare(pc->clk);
return pwmchip_remove(&pc->chip);
}
static struct platform_driver rockchip_pwm_driver = {
.driver = {
.name = "rockchip-pwm",
.of_match_table = rockchip_pwm_dt_ids,
},
.probe = rockchip_pwm_probe,
.remove = rockchip_pwm_remove,
};
module_platform_driver(rockchip_pwm_driver);
MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
MODULE_DESCRIPTION("Rockchip SoC PWM driver");
MODULE_LICENSE("GPL v2");