diff options
Diffstat (limited to 'drivers/pwm/pwm-twl.c')
| -rw-r--r-- | drivers/pwm/pwm-twl.c | 352 | 
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-twl.c b/drivers/pwm/pwm-twl.c new file mode 100644 index 00000000000..04f76725d59 --- /dev/null +++ b/drivers/pwm/pwm-twl.c @@ -0,0 +1,352 @@ +/* + * Driver for TWL4030/6030 Generic Pulse Width Modulator + * + * Copyright (C) 2012 Texas Instruments + * Author: Peter Ujfalusi <peter.ujfalusi@ti.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program.  If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/i2c/twl.h> +#include <linux/slab.h> + +/* + * This driver handles the PWMs of TWL4030 and TWL6030. + * The TRM names for the PWMs on TWL4030 are: PWM0, PWM1 + * TWL6030 also have two PWMs named in the TRM as PWM1, PWM2 + */ + +#define TWL_PWM_MAX		0x7f + +/* Registers, bits and macro for TWL4030 */ +#define TWL4030_GPBR1_REG	0x0c +#define TWL4030_PMBR1_REG	0x0d + +/* GPBR1 register bits */ +#define TWL4030_PWMXCLK_ENABLE	(1 << 0) +#define TWL4030_PWMX_ENABLE	(1 << 2) +#define TWL4030_PWMX_BITS	(TWL4030_PWMX_ENABLE | TWL4030_PWMXCLK_ENABLE) +#define TWL4030_PWM_TOGGLE(pwm, x)	((x) << (pwm)) + +/* PMBR1 register bits */ +#define TWL4030_GPIO6_PWM0_MUTE_MASK		(0x03 << 2) +#define TWL4030_GPIO6_PWM0_MUTE_PWM0		(0x01 << 2) +#define TWL4030_GPIO7_VIBRASYNC_PWM1_MASK	(0x03 << 4) +#define TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1	(0x03 << 4) + +/* Register, bits and macro for TWL6030 */ +#define TWL6030_TOGGLE3_REG	0x92 + +#define TWL6030_PWMXR		(1 << 0) +#define TWL6030_PWMXS		(1 << 1) +#define TWL6030_PWMXEN		(1 << 2) +#define TWL6030_PWM_TOGGLE(pwm, x)	((x) << (pwm * 3)) + +struct twl_pwm_chip { +	struct pwm_chip chip; +	struct mutex mutex; +	u8 twl6030_toggle3; +	u8 twl4030_pwm_mux; +}; + +static inline struct twl_pwm_chip *to_twl(struct pwm_chip *chip) +{ +	return container_of(chip, struct twl_pwm_chip, chip); +} + +static int twl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, +			      int duty_ns, int period_ns) +{ +	int duty_cycle = DIV_ROUND_UP(duty_ns * TWL_PWM_MAX, period_ns) + 1; +	u8 pwm_config[2] = { 1, 0 }; +	int base, ret; + +	/* +	 * To configure the duty period: +	 * On-cycle is set to 1 (the minimum allowed value) +	 * The off time of 0 is not configurable, so the mapping is: +	 * 0 -> off cycle = 2, +	 * 1 -> off cycle = 2, +	 * 2 -> off cycle = 3, +	 * 126 - > off cycle 127, +	 * 127 - > off cycle 1 +	 * When on cycle == off cycle the PWM will be always on +	 */ +	if (duty_cycle == 1) +		duty_cycle = 2; +	else if (duty_cycle > TWL_PWM_MAX) +		duty_cycle = 1; + +	base = pwm->hwpwm * 3; + +	pwm_config[1] = duty_cycle; + +	ret = twl_i2c_write(TWL_MODULE_PWM, pwm_config, base, 2); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to configure PWM\n", pwm->label); + +	return ret; +} + +static int twl4030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val; + +	mutex_lock(&twl->mutex); +	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label); +		goto out; +	} + +	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE); + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); + +	val |= TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE); + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); + +out: +	mutex_unlock(&twl->mutex); +	return ret; +} + +static void twl4030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val; + +	mutex_lock(&twl->mutex); +	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_GPBR1_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to read GPBR1\n", pwm->label); +		goto out; +	} + +	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMX_ENABLE); + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); + +	val &= ~TWL4030_PWM_TOGGLE(pwm->hwpwm, TWL4030_PWMXCLK_ENABLE); + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_GPBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); + +out: +	mutex_unlock(&twl->mutex); +} + +static int twl4030_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val, mask, bits; + +	if (pwm->hwpwm == 1) { +		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK; +		bits = TWL4030_GPIO7_VIBRASYNC_PWM1_PWM1; +	} else { +		mask = TWL4030_GPIO6_PWM0_MUTE_MASK; +		bits = TWL4030_GPIO6_PWM0_MUTE_PWM0; +	} + +	mutex_lock(&twl->mutex); +	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label); +		goto out; +	} + +	/* Save the current MUX configuration for the PWM */ +	twl->twl4030_pwm_mux &= ~mask; +	twl->twl4030_pwm_mux |= (val & mask); + +	/* Select PWM functionality */ +	val &= ~mask; +	val |= bits; + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to request PWM\n", pwm->label); + +out: +	mutex_unlock(&twl->mutex); +	return ret; +} + +static void twl4030_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val, mask; + +	if (pwm->hwpwm == 1) +		mask = TWL4030_GPIO7_VIBRASYNC_PWM1_MASK; +	else +		mask = TWL4030_GPIO6_PWM0_MUTE_MASK; + +	mutex_lock(&twl->mutex); +	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &val, TWL4030_PMBR1_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to read PMBR1\n", pwm->label); +		goto out; +	} + +	/* Restore the MUX configuration for the PWM */ +	val &= ~mask; +	val |= (twl->twl4030_pwm_mux & mask); + +	ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, val, TWL4030_PMBR1_REG); +	if (ret < 0) +		dev_err(chip->dev, "%s: Failed to free PWM\n", pwm->label); + +out: +	mutex_unlock(&twl->mutex); +} + +static int twl6030_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val; + +	mutex_lock(&twl->mutex); +	val = twl->twl6030_toggle3; +	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN); +	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR); + +	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to enable PWM\n", pwm->label); +		goto out; +	} + +	twl->twl6030_toggle3 = val; +out: +	mutex_unlock(&twl->mutex); +	return ret; +} + +static void twl6030_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ +	struct twl_pwm_chip *twl = to_twl(chip); +	int ret; +	u8 val; + +	mutex_lock(&twl->mutex); +	val = twl->twl6030_toggle3; +	val |= TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXR); +	val &= ~TWL6030_PWM_TOGGLE(pwm->hwpwm, TWL6030_PWMXS | TWL6030_PWMXEN); + +	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, val, TWL6030_TOGGLE3_REG); +	if (ret < 0) { +		dev_err(chip->dev, "%s: Failed to disable PWM\n", pwm->label); +		goto out; +	} + +	twl->twl6030_toggle3 = val; +out: +	mutex_unlock(&twl->mutex); +} + +static const struct pwm_ops twl4030_pwm_ops = { +	.config = twl_pwm_config, +	.enable = twl4030_pwm_enable, +	.disable = twl4030_pwm_disable, +	.request = twl4030_pwm_request, +	.free = twl4030_pwm_free, +	.owner = THIS_MODULE, +}; + +static const struct pwm_ops twl6030_pwm_ops = { +	.config = twl_pwm_config, +	.enable = twl6030_pwm_enable, +	.disable = twl6030_pwm_disable, +	.owner = THIS_MODULE, +}; + +static int twl_pwm_probe(struct platform_device *pdev) +{ +	struct twl_pwm_chip *twl; +	int ret; + +	twl = devm_kzalloc(&pdev->dev, sizeof(*twl), GFP_KERNEL); +	if (!twl) +		return -ENOMEM; + +	if (twl_class_is_4030()) +		twl->chip.ops = &twl4030_pwm_ops; +	else +		twl->chip.ops = &twl6030_pwm_ops; + +	twl->chip.dev = &pdev->dev; +	twl->chip.base = -1; +	twl->chip.npwm = 2; +	twl->chip.can_sleep = true; + +	mutex_init(&twl->mutex); + +	ret = pwmchip_add(&twl->chip); +	if (ret < 0) +		return ret; + +	platform_set_drvdata(pdev, twl); + +	return 0; +} + +static int twl_pwm_remove(struct platform_device *pdev) +{ +	struct twl_pwm_chip *twl = platform_get_drvdata(pdev); + +	return pwmchip_remove(&twl->chip); +} + +#ifdef CONFIG_OF +static const struct of_device_id twl_pwm_of_match[] = { +	{ .compatible = "ti,twl4030-pwm" }, +	{ .compatible = "ti,twl6030-pwm" }, +	{ }, +}; +MODULE_DEVICE_TABLE(of, twl_pwm_of_match); +#endif + +static struct platform_driver twl_pwm_driver = { +	.driver = { +		.name = "twl-pwm", +		.of_match_table = of_match_ptr(twl_pwm_of_match), +	}, +	.probe = twl_pwm_probe, +	.remove = twl_pwm_remove, +}; +module_platform_driver(twl_pwm_driver); + +MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>"); +MODULE_DESCRIPTION("PWM driver for TWL4030 and TWL6030"); +MODULE_ALIAS("platform:twl-pwm"); +MODULE_LICENSE("GPL");  | 
