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384461abca
Instead of requiring each driver to care for assigning the owner member
of struct pwm_ops, handle that implicitly using a macro. Note that the
owner member has to be moved to struct pwm_chip, as the ops structure
usually lives in read-only memory and so cannot be modified.
The upside is that new low level drivers cannot forget the assignment and
save one line each. The pwm-crc driver didn't assign .owner, that's not
a problem in practice though as the driver cannot be compiled as a
module.
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti
Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip
Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld
Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
391 lines
9.7 KiB
C
391 lines
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Driver for TWL4030/6030 Pulse Width Modulator used as LED driver
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*
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* Copyright (C) 2012 Texas Instruments
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* Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
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*
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* This driver is a complete rewrite of the former pwm-twl6030.c authorded by:
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* Hemanth V <hemanthv@ti.com>
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*
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* Reference manual for the twl6030 is available at:
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* https://www.ti.com/lit/ds/symlink/twl6030.pdf
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*
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* Limitations:
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* - The twl6030 hardware only supports two period lengths (128 clock ticks and
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* 64 clock ticks), the driver only uses 128 ticks
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* - The hardware doesn't support ON = 0, so the active part of a period doesn't
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* start at its beginning.
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* - The hardware could support inverted polarity (with a similar limitation as
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* for normal: the last clock tick is always inactive).
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* - The hardware emits a constant low output when disabled.
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* - A request for .duty_cycle = 0 results in an output wave with one active
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* clock tick per period. This should better use the disabled state.
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* - The driver only implements setting the relative duty cycle.
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* - The driver doesn't implement .get_state().
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*/
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <linux/mfd/twl.h>
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#include <linux/slab.h>
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/*
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* This driver handles the PWM driven LED terminals of TWL4030 and TWL6030.
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* To generate the signal on TWL4030:
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* - LEDA uses PWMA
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* - LEDB uses PWMB
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* TWL6030 has one LED pin with dedicated LEDPWM
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*/
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#define TWL4030_LED_MAX 0x7f
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#define TWL6030_LED_MAX 0xff
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/* Registers, bits and macro for TWL4030 */
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#define TWL4030_LEDEN_REG 0x00
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#define TWL4030_PWMA_REG 0x01
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#define TWL4030_LEDXON (1 << 0)
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#define TWL4030_LEDXPWM (1 << 4)
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#define TWL4030_LED_PINS (TWL4030_LEDXON | TWL4030_LEDXPWM)
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#define TWL4030_LED_TOGGLE(led, x) ((x) << (led))
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/* Register, bits and macro for TWL6030 */
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#define TWL6030_LED_PWM_CTRL1 0xf4
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#define TWL6030_LED_PWM_CTRL2 0xf5
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#define TWL6040_LED_MODE_HW 0x00
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#define TWL6040_LED_MODE_ON 0x01
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#define TWL6040_LED_MODE_OFF 0x02
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#define TWL6040_LED_MODE_MASK 0x03
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struct twl_pwmled_chip {
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struct pwm_chip chip;
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struct mutex mutex;
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};
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static inline struct twl_pwmled_chip *to_twl(struct pwm_chip *chip)
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{
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return container_of(chip, struct twl_pwmled_chip, chip);
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}
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static int twl4030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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int duty_cycle = DIV_ROUND_UP(duty_ns * TWL4030_LED_MAX, period_ns) + 1;
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u8 pwm_config[2] = { 1, 0 };
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int base, ret;
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/*
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* To configure the duty period:
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* On-cycle is set to 1 (the minimum allowed value)
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* The off time of 0 is not configurable, so the mapping is:
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* 0 -> off cycle = 2,
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* 1 -> off cycle = 2,
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* 2 -> off cycle = 3,
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* 126 - > off cycle 127,
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* 127 - > off cycle 1
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* When on cycle == off cycle the PWM will be always on
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*/
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if (duty_cycle == 1)
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duty_cycle = 2;
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else if (duty_cycle > TWL4030_LED_MAX)
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duty_cycle = 1;
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base = pwm->hwpwm * 2 + TWL4030_PWMA_REG;
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pwm_config[1] = duty_cycle;
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ret = twl_i2c_write(TWL4030_MODULE_LED, pwm_config, base, 2);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
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return ret;
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}
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static int twl4030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
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goto out;
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}
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val |= TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
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ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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return ret;
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}
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static void twl4030_pwmled_disable(struct pwm_chip *chip,
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struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL4030_MODULE_LED, &val, TWL4030_LEDEN_REG);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read LEDEN\n", pwm->label);
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goto out;
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}
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val &= ~TWL4030_LED_TOGGLE(pwm->hwpwm, TWL4030_LED_PINS);
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ret = twl_i2c_write_u8(TWL4030_MODULE_LED, val, TWL4030_LEDEN_REG);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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}
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static int twl4030_pwmled_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 ret;
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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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twl4030_pwmled_disable(chip, pwm);
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return 0;
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}
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/*
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* We cannot skip calling ->config even if state->period ==
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* pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
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* because we might have exited early in the last call to
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* pwm_apply_state because of !state->enabled and so the two values in
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* pwm->state might not be configured in hardware.
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*/
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ret = twl4030_pwmled_config(pwm->chip, pwm,
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state->duty_cycle, state->period);
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if (ret)
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return ret;
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if (!pwm->state.enabled)
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ret = twl4030_pwmled_enable(chip, pwm);
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return ret;
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}
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static const struct pwm_ops twl4030_pwmled_ops = {
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.apply = twl4030_pwmled_apply,
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};
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static int twl6030_pwmled_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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int duty_cycle = (duty_ns * TWL6030_LED_MAX) / period_ns;
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u8 on_time;
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int ret;
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on_time = duty_cycle & 0xff;
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ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, on_time,
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TWL6030_LED_PWM_CTRL1);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label);
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return ret;
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}
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static int twl6030_pwmled_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
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pwm->label);
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goto out;
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}
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val &= ~TWL6040_LED_MODE_MASK;
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val |= TWL6040_LED_MODE_ON;
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ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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return ret;
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}
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static void twl6030_pwmled_disable(struct pwm_chip *chip,
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struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
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pwm->label);
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goto out;
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}
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val &= ~TWL6040_LED_MODE_MASK;
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val |= TWL6040_LED_MODE_OFF;
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ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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}
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static int twl6030_pwmled_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->state.polarity)
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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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twl6030_pwmled_disable(chip, pwm);
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return 0;
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}
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err = twl6030_pwmled_config(pwm->chip, pwm,
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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 = twl6030_pwmled_enable(chip, pwm);
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return err;
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}
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static int twl6030_pwmled_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
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pwm->label);
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goto out;
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}
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val &= ~TWL6040_LED_MODE_MASK;
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val |= TWL6040_LED_MODE_OFF;
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ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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return ret;
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}
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static void twl6030_pwmled_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct twl_pwmled_chip *twl = to_twl(chip);
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int ret;
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u8 val;
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mutex_lock(&twl->mutex);
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ret = twl_i2c_read_u8(TWL6030_MODULE_ID1, &val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0) {
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dev_err(chip->dev, "%s: Failed to read PWM_CTRL2\n",
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pwm->label);
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goto out;
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}
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val &= ~TWL6040_LED_MODE_MASK;
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val |= TWL6040_LED_MODE_HW;
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ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_LED_PWM_CTRL2);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label);
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out:
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mutex_unlock(&twl->mutex);
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}
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static const struct pwm_ops twl6030_pwmled_ops = {
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.apply = twl6030_pwmled_apply,
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.request = twl6030_pwmled_request,
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.free = twl6030_pwmled_free,
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};
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static int twl_pwmled_probe(struct platform_device *pdev)
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{
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struct twl_pwmled_chip *twl;
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twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL);
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if (!twl)
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return -ENOMEM;
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if (twl_class_is_4030()) {
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twl->chip.ops = &twl4030_pwmled_ops;
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twl->chip.npwm = 2;
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} else {
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twl->chip.ops = &twl6030_pwmled_ops;
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twl->chip.npwm = 1;
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}
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twl->chip.dev = &pdev->dev;
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mutex_init(&twl->mutex);
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return devm_pwmchip_add(&pdev->dev, &twl->chip);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id twl_pwmled_of_match[] = {
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{ .compatible = "ti,twl4030-pwmled" },
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{ .compatible = "ti,twl6030-pwmled" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, twl_pwmled_of_match);
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#endif
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static struct platform_driver twl_pwmled_driver = {
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.driver = {
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.name = "twl-pwmled",
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.of_match_table = of_match_ptr(twl_pwmled_of_match),
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},
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.probe = twl_pwmled_probe,
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};
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module_platform_driver(twl_pwmled_driver);
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MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
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MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030 LED outputs");
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MODULE_ALIAS("platform:twl-pwmled");
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MODULE_LICENSE("GPL");
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