From 97e4e7b106b08373f90ff1b8c4daf6c2254386a8 Mon Sep 17 00:00:00 2001 From: Benjamin Larsson Date: Wed, 23 Oct 2024 01:20:06 +0200 Subject: [PATCH] pwm: airoha: Add support for EN7581 SoC Introduce driver for PWM module available on EN7581 SoC. Signed-off-by: Benjamin Larsson Reviewed-by: AngeloGioacchino Del Regno Co-developed-by: Lorenzo Bianconi Signed-off-by: Lorenzo Bianconi --- drivers/pwm/Kconfig | 11 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-airoha.c | 386 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 398 insertions(+) create mode 100644 drivers/pwm/pwm-airoha.c --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -51,6 +51,17 @@ config PWM_AB8500 To compile this driver as a module, choose M here: the module will be called pwm-ab8500. +config PWM_AIROHA + tristate "Airoha PWM support" + depends on ARCH_AIROHA || COMPILE_TEST + depends on OF + select REGMAP_MMIO + help + Generic PWM framework driver for Airoha SoC. + + To compile this driver as a module, choose M here: the module + will be called pwm-airoha. + config PWM_APPLE tristate "Apple SoC PWM support" depends on ARCH_APPLE || COMPILE_TEST --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_SYSFS) += sysfs.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o +obj-$(CONFIG_PWM_AIROHA) += pwm-airoha.o obj-$(CONFIG_PWM_APPLE) += pwm-apple.o obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o --- /dev/null +++ b/drivers/pwm/pwm-airoha.c @@ -0,0 +1,400 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2022 Markus Gothe + * + * Limitations: + * - No disable bit, so a disabled PWM is simulated by setting duty_cycle to 0 + * - Only 8 concurrent waveform generators are available for 8 combinations of + * duty_cycle and period. Waveform generators are shared between 16 GPIO + * pins and 17 SIPO GPIO pins. + * - Supports only normal polarity. + * - On configuration the currently running period is completed. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define REG_SGPIO_LED_DATA 0x0024 +#define SGPIO_LED_DATA_SHIFT_FLAG BIT(31) +#define SGPIO_LED_DATA_DATA GENMASK(16, 0) + +#define REG_SGPIO_CLK_DIVR 0x0028 +#define REG_SGPIO_CLK_DIVR_MASK GENMASK(1, 0) +#define REG_SGPIO_CLK_DLY 0x002c + +#define REG_SIPO_FLASH_MODE_CFG 0x0030 +#define SERIAL_GPIO_FLASH_MODE BIT(1) +#define SERIAL_GPIO_MODE_74HC164 BIT(0) + +#define REG_GPIO_FLASH_PRD_SET(_n) (0x003c + ((_n) << 2)) +#define GPIO_FLASH_PRD_MASK(_n) GENMASK(15 + ((_n) << 4), ((_n) << 4)) + +#define REG_GPIO_FLASH_MAP(_n) (0x004c + ((_n) << 2)) +#define GPIO_FLASH_SETID_MASK(_n) GENMASK(2 + ((_n) << 2), ((_n) << 2)) +#define GPIO_FLASH_EN(_n) BIT(3 + ((_n) << 2)) + +#define REG_SIPO_FLASH_MAP(_n) (0x0054 + ((_n) << 2)) + +#define REG_CYCLE_CFG_VALUE(_n) (0x0098 + ((_n) << 2)) +#define WAVE_GEN_CYCLE_MASK(_n) GENMASK(7 + ((_n) << 3), ((_n) << 3)) + +#define PWM_NUM_BUCKETS 8 + +struct airoha_pwm_bucket { + /* Bitmask of PWM channels using this bucket */ + u64 used; + u64 period_ns; + u64 duty_ns; +}; + +struct airoha_pwm { + struct pwm_chip chip; + + struct regmap *regmap; + + struct device_node *np; + u64 initialized; + + struct airoha_pwm_bucket bucket[PWM_NUM_BUCKETS]; +}; + +/* + * The first 16 GPIO pins, GPIO0-GPIO15, are mapped into 16 PWM channels, 0-15. + * The SIPO GPIO pins are 17 pins which are mapped into 17 PWM channels, 16-32. + * However, we've only got 8 concurrent waveform generators and can therefore + * only use up to 8 different combinations of duty cycle and period at a time. + */ +#define PWM_NUM_GPIO 16 +#define PWM_NUM_SIPO 17 + +/* The PWM hardware supports periods between 4 ms and 1 s */ +#define PERIOD_MIN_NS (4 * NSEC_PER_MSEC) +#define PERIOD_MAX_NS (1 * NSEC_PER_SEC) +/* It is represented internally as 1/250 s between 1 and 250 */ +#define PERIOD_MIN 1 +#define PERIOD_MAX 250 +/* Duty cycle is relative with 255 corresponding to 100% */ +#define DUTY_FULL 255 + +static int airoha_pwm_get_generator(struct airoha_pwm *pc, u64 duty_ns, + u64 period_ns) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) { + if (!pc->bucket[i].used) + continue; + + if (duty_ns == pc->bucket[i].duty_ns && + period_ns == pc->bucket[i].period_ns) + return i; + + /* + * Unlike duty cycle zero, which can be handled by + * disabling PWM, a generator is needed for full duty + * cycle but it can be reused regardless of period + */ + if (duty_ns == DUTY_FULL && pc->bucket[i].duty_ns == DUTY_FULL) + return i; + } + + return -1; +} + +static void airoha_pwm_release_bucket_config(struct airoha_pwm *pc, + unsigned int hwpwm) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) + pc->bucket[i].used &= ~BIT_ULL(hwpwm); +} + +static int airoha_pwm_consume_generator(struct airoha_pwm *pc, + u64 duty_ns, u64 period_ns, + unsigned int hwpwm) +{ + int id = airoha_pwm_get_generator(pc, duty_ns, period_ns); + + if (id < 0) { + int i; + + /* find an unused waveform generator */ + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) { + if (!(pc->bucket[i].used & ~BIT_ULL(hwpwm))) { + id = i; + break; + } + } + } + + if (id >= 0) { + airoha_pwm_release_bucket_config(pc, hwpwm); + pc->bucket[id].used |= BIT_ULL(hwpwm); + pc->bucket[id].period_ns = period_ns; + pc->bucket[id].duty_ns = duty_ns; + } + + return id; +} + +static int airoha_pwm_sipo_init(struct airoha_pwm *pc) +{ + u32 val; + + if (!(pc->initialized >> PWM_NUM_GPIO)) + return 0; + + regmap_clear_bits(pc->regmap, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_MODE_74HC164); + + /* Configure shift register timings, use 32x divisor */ + regmap_write(pc->regmap, REG_SGPIO_CLK_DIVR, + FIELD_PREP(REG_SGPIO_CLK_DIVR_MASK, 0x3)); + + /* + * The actual delay is clock + 1. + * Notice that clock delay should not be greater + * than (divisor / 2) - 1. + * Set to 0 by default. (aka 1) + */ + regmap_write(pc->regmap, REG_SGPIO_CLK_DLY, 0x0); + + /* + * It it necessary to after muxing explicitly shift out all + * zeroes to initialize the shift register before enabling PWM + * mode because in PWM mode SIPO will not start shifting until + * it needs to output a non-zero value (bit 31 of led_data + * indicates shifting in progress and it must return to zero + * before led_data can be written or PWM mode can be set) + */ + if (regmap_read_poll_timeout(pc->regmap, REG_SGPIO_LED_DATA, val, + !(val & SGPIO_LED_DATA_SHIFT_FLAG), 10, + 200 * USEC_PER_MSEC)) + return -ETIMEDOUT; + + regmap_clear_bits(pc->regmap, REG_SGPIO_LED_DATA, SGPIO_LED_DATA_DATA); + if (regmap_read_poll_timeout(pc->regmap, REG_SGPIO_LED_DATA, val, + !(val & SGPIO_LED_DATA_SHIFT_FLAG), 10, + 200 * USEC_PER_MSEC)) + return -ETIMEDOUT; + + /* Set SIPO in PWM mode */ + regmap_set_bits(pc->regmap, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_FLASH_MODE); + + return 0; +} + +static void airoha_pwm_calc_bucket_config(struct airoha_pwm *pc, int index, + u64 duty_ns, u64 period_ns) +{ + u32 period, duty, mask, val; + u64 tmp; + + tmp = duty_ns * DUTY_FULL; + duty = clamp_val(div64_u64(tmp, period_ns), 0, DUTY_FULL); + tmp = period_ns * 25; + period = clamp_val(div64_u64(tmp, 100000000), PERIOD_MIN, PERIOD_MAX); + + /* Configure frequency divisor */ + mask = WAVE_GEN_CYCLE_MASK(index % 4); + val = (period << __ffs(mask)) & mask; + regmap_update_bits(pc->regmap, REG_CYCLE_CFG_VALUE(index / 4), + mask, val); + + /* Configure duty cycle */ + duty = ((DUTY_FULL - duty) << 8) | duty; + mask = GPIO_FLASH_PRD_MASK(index % 2); + val = (duty << __ffs(mask)) & mask; + regmap_update_bits(pc->regmap, REG_GPIO_FLASH_PRD_SET(index / 2), + mask, val); +} + +static void airoha_pwm_config_flash_map(struct airoha_pwm *pc, + unsigned int hwpwm, int index) +{ + u32 addr, mask, val; + + if (hwpwm < PWM_NUM_GPIO) { + addr = REG_GPIO_FLASH_MAP(hwpwm / 8); + } else { + addr = REG_SIPO_FLASH_MAP(hwpwm / 8); + hwpwm -= PWM_NUM_GPIO; + } + + if (index < 0) { + /* + * Change of waveform takes effect immediately but + * disabling has some delay so to prevent glitching + * only the enable bit is touched when disabling + */ + regmap_clear_bits(pc->regmap, addr, GPIO_FLASH_EN(hwpwm % 8)); + return; + } + + mask = GPIO_FLASH_SETID_MASK(hwpwm % 8); + val = ((index & 7) << __ffs(mask)) & mask; + regmap_update_bits(pc->regmap, addr, mask, val); + regmap_set_bits(pc->regmap, addr, GPIO_FLASH_EN(hwpwm % 8)); +} + +static int airoha_pwm_config(struct airoha_pwm *pc, struct pwm_device *pwm, + u64 duty_ns, u64 period_ns) +{ + int index = -1; + + index = airoha_pwm_consume_generator(pc, duty_ns, period_ns, + pwm->hwpwm); + if (index < 0) + return -EBUSY; + + if (!(pc->initialized & BIT_ULL(pwm->hwpwm)) && + pwm->hwpwm >= PWM_NUM_GPIO) + airoha_pwm_sipo_init(pc); + + if (index >= 0) { + airoha_pwm_calc_bucket_config(pc, index, duty_ns, period_ns); + airoha_pwm_config_flash_map(pc, pwm->hwpwm, index); + } else { + airoha_pwm_config_flash_map(pc, pwm->hwpwm, index); + airoha_pwm_release_bucket_config(pc, pwm->hwpwm); + } + + pc->initialized |= BIT_ULL(pwm->hwpwm); + + return 0; +} + +static void airoha_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct airoha_pwm *pc = container_of(chip, struct airoha_pwm, chip); + + /* Disable PWM and release the waveform */ + airoha_pwm_config_flash_map(pc, pwm->hwpwm, -1); + airoha_pwm_release_bucket_config(pc, pwm->hwpwm); + + pc->initialized &= ~BIT_ULL(pwm->hwpwm); + if (!(pc->initialized >> PWM_NUM_GPIO)) + regmap_clear_bits(pc->regmap, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_FLASH_MODE); +} + +static int airoha_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct airoha_pwm *pc = container_of(chip, struct airoha_pwm, chip); + u64 duty = state->enabled ? state->duty_cycle : 0; + u64 period = state->period; + + /* Only normal polarity is supported */ + if (state->polarity == PWM_POLARITY_INVERSED) + return -EINVAL; + + if (!state->enabled) { + airoha_pwm_disable(chip, pwm); + return 0; + } + + if (period < PERIOD_MIN_NS) + return -EINVAL; + + if (period > PERIOD_MAX_NS) + period = PERIOD_MAX_NS; + + return airoha_pwm_config(pc, pwm, duty, period); +} + +static int airoha_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct airoha_pwm *pc = container_of(chip, struct airoha_pwm, chip); + int i; + + /* find hwpwm in waveform generator bucket */ + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) { + if (pc->bucket[i].used & BIT_ULL(pwm->hwpwm)) { + state->enabled = pc->initialized & BIT_ULL(pwm->hwpwm); + state->polarity = PWM_POLARITY_NORMAL; + state->period = pc->bucket[i].period_ns; + state->duty_cycle = pc->bucket[i].duty_ns; + break; + } + } + + if (i == ARRAY_SIZE(pc->bucket)) + state->enabled = false; + + return 0; +} + +static const struct pwm_ops airoha_pwm_ops = { + .get_state = airoha_pwm_get_state, + .apply = airoha_pwm_apply, + .owner = THIS_MODULE, +}; + +static int airoha_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct airoha_pwm *pc; + + pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL); + if (!pc) + return -ENOMEM; + + pc->np = dev->of_node; + pc->chip.dev = dev; + pc->chip.ops = &airoha_pwm_ops; + pc->chip.npwm = PWM_NUM_GPIO + PWM_NUM_SIPO; + + pc->regmap = device_node_to_regmap(dev->parent->of_node); + if (IS_ERR(pc->regmap)) + return PTR_ERR(pc->regmap); + + platform_set_drvdata(pdev, pc); + + return pwmchip_add(&pc->chip); +} + +static int airoha_pwm_remove(struct platform_device *pdev) +{ + struct airoha_pwm *pc = platform_get_drvdata(pdev); + + pwmchip_remove(&pc->chip); + + return 0; +} + +static const struct of_device_id airoha_pwm_of_match[] = { + { .compatible = "airoha,en7581-pwm" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, airoha_pwm_of_match); + +static struct platform_driver airoha_pwm_driver = { + .driver = { + .name = "pwm-airoha", + .of_match_table = airoha_pwm_of_match, + }, + .probe = airoha_pwm_probe, + .remove = airoha_pwm_remove, +}; +module_platform_driver(airoha_pwm_driver); + +MODULE_AUTHOR("Lorenzo Bianconi "); +MODULE_AUTHOR("Markus Gothe "); +MODULE_AUTHOR("Benjamin Larsson "); +MODULE_DESCRIPTION("Airoha EN7581 PWM driver"); +MODULE_LICENSE("GPL");