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![Uwe Kleine-König](/assets/img/avatar_default.png)
To eventually get rid of all legacy drivers convert this driver to the modern world implementing .apply(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
330 lines
7.7 KiB
C
330 lines
7.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* TI/National Semiconductor LP3943 PWM driver
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*
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* Copyright 2013 Texas Instruments
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*
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* Author: Milo Kim <milo.kim@ti.com>
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*/
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/mfd/lp3943.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <linux/slab.h>
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#define LP3943_MAX_DUTY 255
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#define LP3943_MIN_PERIOD 6250
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#define LP3943_MAX_PERIOD 1600000
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struct lp3943_pwm {
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struct pwm_chip chip;
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struct lp3943 *lp3943;
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struct lp3943_platform_data *pdata;
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};
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static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip)
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{
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return container_of(_chip, struct lp3943_pwm, chip);
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}
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static struct lp3943_pwm_map *
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lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
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{
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struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
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struct lp3943 *lp3943 = lp3943_pwm->lp3943;
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struct lp3943_pwm_map *pwm_map;
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int i, offset;
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pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL);
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if (!pwm_map)
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return ERR_PTR(-ENOMEM);
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pwm_map->output = pdata->pwms[hwpwm]->output;
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pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;
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for (i = 0; i < pwm_map->num_outputs; i++) {
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offset = pwm_map->output[i];
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/* Return an error if the pin is already assigned */
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if (test_and_set_bit(offset, &lp3943->pin_used)) {
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kfree(pwm_map);
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return ERR_PTR(-EBUSY);
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}
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}
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return pwm_map;
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}
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static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
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struct lp3943_pwm_map *pwm_map;
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pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
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if (IS_ERR(pwm_map))
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return PTR_ERR(pwm_map);
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return pwm_set_chip_data(pwm, pwm_map);
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}
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static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
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struct lp3943_pwm_map *pwm_map)
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{
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struct lp3943 *lp3943 = lp3943_pwm->lp3943;
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int i, offset;
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for (i = 0; i < pwm_map->num_outputs; i++) {
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offset = pwm_map->output[i];
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clear_bit(offset, &lp3943->pin_used);
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}
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kfree(pwm_map);
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}
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static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
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struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
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lp3943_pwm_free_map(lp3943_pwm, pwm_map);
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}
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static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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u64 duty_ns, u64 period_ns)
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{
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struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
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struct lp3943 *lp3943 = lp3943_pwm->lp3943;
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u8 val, reg_duty, reg_prescale;
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int err;
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/*
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* How to configure the LP3943 PWMs
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*
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* 1) Period = 6250 ~ 1600000
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* 2) Prescale = period / 6250 -1
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* 3) Duty = input duty
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*
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* Prescale and duty are register values
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*/
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if (pwm->hwpwm == 0) {
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reg_prescale = LP3943_REG_PRESCALE0;
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reg_duty = LP3943_REG_PWM0;
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} else {
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reg_prescale = LP3943_REG_PRESCALE1;
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reg_duty = LP3943_REG_PWM1;
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}
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/*
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* Note that after this clamping, period_ns fits into an int. This is
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* helpful because we can resort to integer division below instead of
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* the (more expensive) 64 bit division.
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*/
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period_ns = clamp(period_ns, (u64)LP3943_MIN_PERIOD, (u64)LP3943_MAX_PERIOD);
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val = (u8)((int)period_ns / LP3943_MIN_PERIOD - 1);
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err = lp3943_write_byte(lp3943, reg_prescale, val);
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if (err)
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return err;
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duty_ns = min(duty_ns, period_ns);
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val = (u8)((int)duty_ns * LP3943_MAX_DUTY / (int)period_ns);
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return lp3943_write_byte(lp3943, reg_duty, val);
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}
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static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
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struct lp3943_pwm_map *pwm_map,
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u8 val)
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{
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struct lp3943 *lp3943 = lp3943_pwm->lp3943;
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const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
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int i, index, err;
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for (i = 0; i < pwm_map->num_outputs; i++) {
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index = pwm_map->output[i];
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err = lp3943_update_bits(lp3943, mux[index].reg,
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mux[index].mask,
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val << mux[index].shift);
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if (err)
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return err;
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}
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return 0;
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}
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static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
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struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
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u8 val;
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if (pwm->hwpwm == 0)
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val = LP3943_DIM_PWM0;
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else
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val = LP3943_DIM_PWM1;
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/*
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* Each PWM generator is set to control any of outputs of LP3943.
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* To enable/disable the PWM, these output pins should be configured.
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*/
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return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
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}
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static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
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struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
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/*
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* LP3943 outputs are open-drain, so the pin should be configured
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* when the PWM is disabled.
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*/
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lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
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}
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static int lp3943_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
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const struct pwm_state *state)
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{
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int err;
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if (state->polarity != PWM_POLARITY_NORMAL)
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return -EINVAL;
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if (!state->enabled) {
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if (pwm->state.enabled)
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lp3943_pwm_disable(chip, pwm);
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return 0;
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}
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err = lp3943_pwm_config(chip, pwm, state->duty_cycle, state->period);
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if (err)
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return err;
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if (!pwm->state.enabled)
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err = lp3943_pwm_enable(chip, pwm);
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return err;
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}
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static const struct pwm_ops lp3943_pwm_ops = {
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.request = lp3943_pwm_request,
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.free = lp3943_pwm_free,
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.apply = lp3943_pwm_apply,
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.owner = THIS_MODULE,
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};
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static int lp3943_pwm_parse_dt(struct device *dev,
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struct lp3943_pwm *lp3943_pwm)
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{
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static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
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struct device_node *node = dev->of_node;
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struct lp3943_platform_data *pdata;
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struct lp3943_pwm_map *pwm_map;
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enum lp3943_pwm_output *output;
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int i, err, proplen, count = 0;
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u32 num_outputs;
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if (!node)
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return -EINVAL;
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pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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/*
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* Read the output map configuration from the device tree.
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* Each of the two PWM generators can drive zero or more outputs.
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*/
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for (i = 0; i < LP3943_NUM_PWMS; i++) {
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if (!of_get_property(node, name[i], &proplen))
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continue;
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num_outputs = proplen / sizeof(u32);
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if (num_outputs == 0)
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continue;
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output = devm_kcalloc(dev, num_outputs, sizeof(*output),
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GFP_KERNEL);
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if (!output)
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return -ENOMEM;
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err = of_property_read_u32_array(node, name[i], output,
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num_outputs);
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if (err)
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return err;
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pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
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if (!pwm_map)
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return -ENOMEM;
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pwm_map->output = output;
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pwm_map->num_outputs = num_outputs;
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pdata->pwms[i] = pwm_map;
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count++;
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}
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if (count == 0)
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return -ENODATA;
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lp3943_pwm->pdata = pdata;
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return 0;
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}
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static int lp3943_pwm_probe(struct platform_device *pdev)
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{
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struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
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struct lp3943_pwm *lp3943_pwm;
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int ret;
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lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
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if (!lp3943_pwm)
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return -ENOMEM;
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lp3943_pwm->pdata = lp3943->pdata;
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if (!lp3943_pwm->pdata) {
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if (IS_ENABLED(CONFIG_OF))
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ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
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else
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ret = -ENODEV;
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if (ret)
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return ret;
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}
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lp3943_pwm->lp3943 = lp3943;
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lp3943_pwm->chip.dev = &pdev->dev;
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lp3943_pwm->chip.ops = &lp3943_pwm_ops;
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lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
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return devm_pwmchip_add(&pdev->dev, &lp3943_pwm->chip);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id lp3943_pwm_of_match[] = {
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{ .compatible = "ti,lp3943-pwm", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
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#endif
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static struct platform_driver lp3943_pwm_driver = {
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.probe = lp3943_pwm_probe,
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.driver = {
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.name = "lp3943-pwm",
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.of_match_table = of_match_ptr(lp3943_pwm_of_match),
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},
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};
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module_platform_driver(lp3943_pwm_driver);
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MODULE_DESCRIPTION("LP3943 PWM driver");
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MODULE_ALIAS("platform:lp3943-pwm");
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MODULE_AUTHOR("Milo Kim");
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MODULE_LICENSE("GPL");
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