400 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2023 Rockchip Electronics Co., Ltd.
*
* Author: Damon Ding <damon.ding@rock-chips.com>
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/time.h>
#include "rkx110_x120.h"
#include "rkx120_reg.h"
/*
* regs for pwm v1-v3
*/
#define PWM_CTRL_TIMER_EN (1 << 0)
#define PWM_CTRL_OUTPUT_EN (1 << 3)
#define PWM_ENABLE (1 << 0)
#define PWM_MODE_SHIFT 1
#define PWM_MODE_MASK (0x3 << PWM_MODE_SHIFT)
#define PWM_ONESHOT (0 << PWM_MODE_SHIFT)
#define PWM_CONTINUOUS (1 << PWM_MODE_SHIFT)
#define PWM_CAPTURE (2 << PWM_MODE_SHIFT)
#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_OUTPUT_CENTER (1 << 5)
#define PWM_LOCK_EN (1 << 6)
#define PWM_LP_DISABLE (0 << 8)
#define PWM_CLK_SEL_SHIFT 9
#define PWM_CLK_SEL_MASK (1 << PWM_CLK_SEL_SHIFT)
#define PWM_SEL_NO_SCALED_CLOCK (0 << PWM_CLK_SEL_SHIFT)
#define PWM_SEL_SCALED_CLOCK (1 << PWM_CLK_SEL_SHIFT)
#define PWM_PRESCELE_SHIFT 12
#define PWM_PRESCALE_MASK (0x3 << PWM_PRESCELE_SHIFT)
#define PWM_SCALE_SHIFT 16
#define PWM_SCALE_MASK (0xff << PWM_SCALE_SHIFT)
#define PWM_ONESHOT_COUNT_SHIFT 24
#define PWM_ONESHOT_COUNT_MASK (0xff << PWM_ONESHOT_COUNT_SHIFT)
#define PWM_REG_INTSTS(n) ((3 - (n)) * 0x10 + 0x10)
#define PWM_REG_INT_EN(n) ((3 - (n)) * 0x10 + 0x14)
#define PWM_CH_INT(n) BIT(n)
#define PWM_DCLK_RATE 24000000
struct rkx120_pwm_chip {
struct pwm_chip chip;
struct rk_serdes *serdes;
const struct rkx120_pwm_data *data;
unsigned long clk_rate;
bool center_aligned;
bool oneshot_en;
u32 remote_id;
u32 channel_id;
};
struct rkx120_pwm_regs {
unsigned long base;
unsigned long duty;
unsigned long period;
unsigned long cntr;
unsigned long ctrl;
};
struct rkx120_pwm_data {
struct rkx120_pwm_regs regs;
unsigned int prescaler;
bool supports_polarity;
bool supports_lock;
u32 enable_conf;
u32 enable_conf_mask;
u32 oneshot_cnt_max;
};
static inline int rkx120_pwm_write(struct rk_serdes *serdes, u8 remote_id, u32 reg, u32 val)
{
struct i2c_client *client = serdes->chip[remote_id].client;
return serdes->i2c_write_reg(client, reg, val);
}
static inline int rkx120_pwm_read(struct rk_serdes *serdes, u8 remote_id, u32 reg, u32 *val)
{
struct i2c_client *client = serdes->chip[remote_id].client;
return serdes->i2c_read_reg(client, reg, val);
}
static inline struct rkx120_pwm_chip *to_rkx120_pwm_chip(struct pwm_chip *c)
{
return container_of(c, struct rkx120_pwm_chip, chip);
}
static int rkx120_pwm_get_state(struct pwm_chip *chip,
struct pwm_device *pwm,
struct pwm_state *state)
{
struct rkx120_pwm_chip *pc = to_rkx120_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
u64 tmp;
u32 val;
rkx120_pwm_read(pc->serdes, pc->remote_id, PWM_PERIOD_HPR(pc->channel_id), &val);
tmp = val * pc->data->prescaler * NSEC_PER_SEC;
state->period = DIV_ROUND_CLOSEST_ULL(tmp, pc->clk_rate);
rkx120_pwm_read(pc->serdes, pc->remote_id, PWM_DUTY_LPR(pc->channel_id), &val);
tmp = val * pc->data->prescaler * NSEC_PER_SEC;
state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pc->clk_rate);
rkx120_pwm_read(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), &val);
if (pc->oneshot_en)
enable_conf &= ~PWM_CONTINUOUS;
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;
return 0;
}
static void rkx120_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rkx120_pwm_chip *pc = to_rkx120_pwm_chip(chip);
unsigned long period, duty, delay_ns;
u64 div;
u32 ctrl;
u8 dclk_div = 1;
#ifdef CONFIG_PWM_ROCKCHIP_ONESHOT
if (state->oneshot_count > 0 && state->oneshot_count <= pc->data->oneshot_cnt_max)
dclk_div = 2;
#endif
/*
* 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 = (u64)pc->clk_rate * state->period;
period = DIV_ROUND_CLOSEST_ULL(div, dclk_div * pc->data->prescaler * NSEC_PER_SEC);
div = (u64)pc->clk_rate * state->duty_cycle;
duty = DIV_ROUND_CLOSEST_ULL(div, dclk_div * pc->data->prescaler * NSEC_PER_SEC);
if (pc->data->supports_lock) {
div = (u64)10 * NSEC_PER_SEC * dclk_div * pc->data->prescaler;
delay_ns = DIV_ROUND_UP_ULL(div, pc->clk_rate);
}
/*
* Lock the period and duty of previous configuration, then
* change the duty and period, that would not be effective.
*/
rkx120_pwm_read(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), &ctrl);
#ifdef CONFIG_PWM_ROCKCHIP_ONESHOT
if (state->oneshot_count > 0 && state->oneshot_count <= pc->data->oneshot_cnt_max) {
/*
* This is a workaround, an uncertain waveform will be
* generated after oneshot ends. It is needed to enable
* the dclk scale function to resolve it. It doesn't
* matter what the scale factor is, just make sure the
* scale function is turned on, for which we set scale
* factor to 2.
*/
ctrl &= ~PWM_SCALE_MASK;
ctrl |= (dclk_div / 2) << PWM_SCALE_SHIFT;
ctrl &= ~PWM_CLK_SEL_MASK;
ctrl |= PWM_SEL_SCALED_CLOCK;
pc->oneshot_en = true;
ctrl &= ~PWM_MODE_MASK;
ctrl |= PWM_ONESHOT;
ctrl &= ~PWM_ONESHOT_COUNT_MASK;
ctrl |= (state->oneshot_count - 1) << PWM_ONESHOT_COUNT_SHIFT;
} else {
ctrl &= ~PWM_SCALE_MASK;
ctrl &= ~PWM_CLK_SEL_MASK;
ctrl |= PWM_SEL_NO_SCALED_CLOCK;
if (state->oneshot_count)
dev_err(chip->dev, "Oneshot_count must be between 1 and %d.\n",
pc->data->oneshot_cnt_max);
pc->oneshot_en = false;
ctrl &= ~PWM_MODE_MASK;
ctrl |= PWM_CONTINUOUS;
ctrl &= ~PWM_ONESHOT_COUNT_MASK;
}
#endif
/*
* Lock the period and duty of previous configuration, then
* change the duty and period, that would not be effective.
*/
if (pc->data->supports_lock) {
ctrl |= PWM_LOCK_EN;
rkx120_pwm_write(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), ctrl);
}
rkx120_pwm_write(pc->serdes, pc->remote_id, PWM_PERIOD_HPR(pc->channel_id), period);
rkx120_pwm_write(pc->serdes, pc->remote_id, PWM_DUTY_LPR(pc->channel_id), 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. It
* takes 10 dclk cycles to make sure lock works before unlocking.
*/
if (pc->data->supports_lock) {
ctrl &= ~PWM_LOCK_EN;
ndelay(delay_ns);
}
rkx120_pwm_write(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), ctrl);
}
static int rkx120_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm, bool enable)
{
struct rkx120_pwm_chip *pc = to_rkx120_pwm_chip(chip);
u32 enable_conf = pc->data->enable_conf;
u32 val;
rkx120_pwm_read(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), &val);
val &= ~pc->data->enable_conf_mask;
if (pc->data->enable_conf_mask & PWM_OUTPUT_CENTER) {
if (pc->center_aligned)
val |= PWM_OUTPUT_CENTER;
}
if (enable) {
val |= enable_conf;
if (pc->oneshot_en)
val &= ~PWM_CONTINUOUS;
} else {
val &= ~enable_conf;
}
rkx120_pwm_write(pc->serdes, pc->remote_id, PWM_CTRL(pc->channel_id), val);
return 0;
}
static int rkx120_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct rkx120_pwm_chip *pc = to_rkx120_pwm_chip(chip);
struct pwm_state curstate;
bool enabled;
int ret = 0;
pwm_get_state(pwm, &curstate);
enabled = curstate.enabled;
if (state->polarity != curstate.polarity && enabled &&
!pc->data->supports_lock) {
ret = rkx120_pwm_enable(chip, pwm, false);
if (ret)
return ret;
enabled = false;
}
rkx120_pwm_config(chip, pwm, state);
if (state->enabled != enabled) {
ret = rkx120_pwm_enable(chip, pwm, state->enabled);
if (ret)
return ret;
}
return ret;
}
static const struct pwm_ops rkx120_pwm_ops = {
.get_state = rkx120_pwm_get_state,
.apply = rkx120_pwm_apply,
.owner = THIS_MODULE,
};
static const struct rkx120_pwm_data rkx120_pwm_data = {
.prescaler = 1,
.supports_polarity = true,
.supports_lock = true,
.enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE |
PWM_CONTINUOUS,
.enable_conf_mask = GENMASK(2, 0) | BIT(5) | BIT(8),
.oneshot_cnt_max = 0x100,
};
static const struct of_device_id rkx120_pwm_dt_ids[] = {
{ .compatible = "rockchip,rkx120-pwm", .data = &rkx120_pwm_data},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rkx120_pwm_dt_ids);
static int rkx120_pwm_probe(struct platform_device *pdev)
{
struct rk_serdes *serdes = dev_get_drvdata(pdev->dev.parent);
const struct of_device_id *id;
struct rkx120_pwm_chip *pc;
u32 remote_id, channel_id;
int ret;
id = of_match_device(rkx120_pwm_dt_ids, &pdev->dev);
if (!id)
return -EINVAL;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
return -ENOMEM;
platform_set_drvdata(pdev, pc);
pc->data = id->data;
pc->chip.dev = &pdev->dev;
pc->chip.ops = &rkx120_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;
}
pc->clk_rate = PWM_DCLK_RATE;
pc->serdes = serdes;
pc->center_aligned = device_property_read_bool(&pdev->dev, "center-aligned");
ret = of_property_read_u32(pdev->dev.of_node, "channel-id", &channel_id);
if (ret) {
dev_err(&pdev->dev, "failed to read pwm channel id\n");
return ret;
}
pc->channel_id = channel_id;
ret = of_property_read_u32(pdev->dev.of_node, "remote-id", &remote_id);
if (ret) {
dev_err(&pdev->dev, "failed to read pwm remote id\n");
return ret;
}
pc->remote_id = remote_id;
ret = pwmchip_add(&pc->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
return ret;
}
return 0;
}
static int rkx120_pwm_remove(struct platform_device *pdev)
{
struct rkx120_pwm_chip *pc = platform_get_drvdata(pdev);
pwmchip_remove(&pc->chip);
return 0;
}
static struct platform_driver rkx120_pwm_driver = {
.driver = {
.name = "rkx120-pwm",
.of_match_table = rkx120_pwm_dt_ids,
},
.probe = rkx120_pwm_probe,
.remove = rkx120_pwm_remove,
};
module_platform_driver(rkx120_pwm_driver);
MODULE_LICENSE("GPL");