Add support for RZ/G2L MTU3a PWM driver. The IP supports following PWM modes 1) PWM mode{1,2} 2) Reset-synchronized PWM mode 3) Complementary PWM mode{1,2,3} This patch adds basic pwm mode 1 support for RZ/G2L MTU3a pwm driver by creating separate logical channels for each IOs. Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> --- v11->v12: * Updated header file to <linux/mfd/rz-mtu3.h> as core driver is in MFD. * Reordered get_state() v10->v11: * No change. v9->v10: * No change. v8->v9: * Added prescale/duty_cycle variables to struct rz_mtu3_pwm_chip and cached this values in rz_mtu3_pwm_config and used this cached values in get_state(), if PWM is disabled. * Added return code for get_state() v7->v8: * Simplified rz_mtu3_pwm_request by calling rz_mtu3_request_channel() * Simplified rz_mtu3_pwm_free by calling rz_mtu3_release_channel() v6->v7: * Added channel specific mutex lock to avoid race between counter device and rz_mtu3_pwm_{request,free} * Added pm_runtime_resume_and_get in rz_mtu3_pwm_enable() * Added pm_runtime_put_sync in rz_mtu3_pwm_disable() * Updated rz_mtu3_pwm_config() * Updated rz_mtu3_pwm_apply() v5->v6: * Updated commit and Kconfig description * Sorted the header * Replaced dev_get_drvdata from rz_mtu3_pwm_pm_disable() * Replaced SET_RUNTIME_PM_OPS->DEFINE_RUNTIME_DEV_PM_OPS and removed __maybe_unused from suspend/resume() v4->v5: * pwm device is instantiated by mtu3a core driver. v3->v4: * There is no resource associated with "rz-mtu3-pwm" compatible and moved the code to mfd subsystem as it binds against "rz-mtu". * Removed struct platform_driver rz_mtu3_pwm_driver. v2->v3: * No change. v1->v2: * Modelled as a single PWM device handling multiple channles. * Used PM framework to manage the clocks. --- drivers/pwm/Kconfig | 11 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-rz-mtu3.c | 485 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 497 insertions(+) create mode 100644 drivers/pwm/pwm-rz-mtu3.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 31cdc9dae3c5..c54cbeabe093 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -492,6 +492,17 @@ config PWM_ROCKCHIP Generic PWM framework driver for the PWM controller found on Rockchip SoCs. +config PWM_RZ_MTU3 + tristate "Renesas RZ/G2L MTU3a PWM Timer support" + depends on RZ_MTU3 || COMPILE_TEST + depends on HAS_IOMEM + help + This driver exposes the MTU3a PWM Timer controller found in Renesas + RZ/G2L like chips through the PWM API. + + To compile this driver as a module, choose M here: the module + will be called pwm-rz-mtu3. + config PWM_SAMSUNG tristate "Samsung PWM support" depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index a95aabae9115..6b75c0145336 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o obj-$(CONFIG_PWM_RZV2M) += pwm-rzv2m.o obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o +obj-$(CONFIG_PWM_RZ_MTU3) += pwm-rz-mtu3.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o obj-$(CONFIG_PWM_SL28CPLD) += pwm-sl28cpld.o diff --git a/drivers/pwm/pwm-rz-mtu3.c b/drivers/pwm/pwm-rz-mtu3.c new file mode 100644 index 000000000000..d94e3fc36dfb --- /dev/null +++ b/drivers/pwm/pwm-rz-mtu3.c @@ -0,0 +1,485 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L MTU3a PWM Timer driver + * + * Copyright (C) 2022 Renesas Electronics Corporation + * + * Hardware manual for this IP can be found here + * https://www.renesas.com/eu/en/document/mah/rzg2l-group-rzg2lc-group-users-manual-hardware-0?language=en + * + * Limitations: + * - When PWM is disabled, the output is driven to Hi-Z. + * - While the hardware supports both polarities, the driver (for now) + * only handles normal polarity. + * - While the hardware supports pwm mode{1,2}, reset-synchronized pwm and + * complementary pwm modes, the driver (for now) only handles pwm mode1. + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/limits.h> +#include <linux/mfd/rz-mtu3.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/pwm.h> +#include <linux/time.h> + +#define RZ_MTU3_TMDR1_MD_NORMAL (0) +#define RZ_MTU3_TMDR1_MD_PWM_MODE_1 (2) + +#define RZ_MTU3_TIOR_OC_RETAIN (0) +#define RZ_MTU3_TIOR_OC_0_H_COMP_MATCH (2) +#define RZ_MTU3_TIOR_OC_1_TOGGLE (7) +#define RZ_MTU3_TIOR_OC_IOA GENMASK(3, 0) + +#define RZ_MTU3_TCR_CCLR_TGRC (5 << 5) +#define RZ_MTU3_TCR_CKEG_RISING (0 << 3) + +#define RZ_MTU3_TCR_TPCS GENMASK(2, 0) + +#define RZ_MTU3_MAX_PWM_MODE1_CHANNELS (12) + +#define RZ_MTU3_MAX_HW_PWM_CHANNELS (7) + +static const u8 rz_mtu3_pwm_mode1_num_ios[] = { 2, 1, 1, 2, 2, 2, 2 }; + +/** + * struct rz_mtu3_pwm_chip - MTU3 pwm private data + * + * @chip: MTU3 pwm chip data + * @clk: MTU3 module clock + * @lock: Lock to prevent concurrent access for usage count + * @rate: MTU3 clock rate + * @user_count: MTU3 usage count + * @rz_mtu3_channel: HW channels for the PWM + */ + +struct rz_mtu3_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + struct mutex lock; + unsigned long rate; + u32 user_count[RZ_MTU3_MAX_HW_PWM_CHANNELS]; + struct rz_mtu3_channel *ch[RZ_MTU3_MAX_HW_PWM_CHANNELS]; + + /* + * The driver cannot read the current duty cycle/prescale from the + * hardware if the hardware is disabled. Cache the last programmed + * duty cycle/prescale value to return in that case. + */ + u8 prescale[RZ_MTU3_MAX_HW_PWM_CHANNELS]; + unsigned int duty_cycle[RZ_MTU3_MAX_PWM_MODE1_CHANNELS]; +}; + +static inline struct rz_mtu3_pwm_chip *to_rz_mtu3_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct rz_mtu3_pwm_chip, chip); +} + +static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip *rz_mtu3, + u64 period_cycles) +{ + u32 prescaled_period_cycles; + u8 prescale; + + prescaled_period_cycles = period_cycles >> 16; + if (prescaled_period_cycles >= 16) + prescale = 3; + else + prescale = (fls(prescaled_period_cycles) + 1) / 2; + + return prescale; +} + +static struct rz_mtu3_channel * +rz_mtu3_get_hw_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 channel) +{ + unsigned int i, ch_index = 0; + + for (i = 0; i < ARRAY_SIZE(rz_mtu3_pwm_mode1_num_ios); i++) { + ch_index += rz_mtu3_pwm_mode1_num_ios[i]; + + if (ch_index > channel) + break; + } + + return rz_mtu3_pwm->ch[i]; +} + +static u32 rz_mtu3_get_hw_channel_index(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + struct rz_mtu3_channel *ch) +{ + u32 i; + + for (i = 0; i < ARRAY_SIZE(rz_mtu3_pwm_mode1_num_ios); i++) { + if (ch == rz_mtu3_pwm->ch[i]) + break; + } + + return i; +} + +static bool rz_mtu3_pwm_is_second_channel(u32 ch_index, u32 hwpwm) +{ + u32 i, pwm_ch_index = 0; + + for (i = 0; i < ch_index; i++) + pwm_ch_index += rz_mtu3_pwm_mode1_num_ios[i]; + + return pwm_ch_index != hwpwm; +} + +static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + u32 hwpwm) +{ + struct rz_mtu3_channel *ch; + bool is_channel_en; + u32 ch_index; + u8 val; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + is_channel_en = rz_mtu3_is_enabled(ch); + + if (rz_mtu3_pwm_is_second_channel(ch_index, hwpwm)) + val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TIORL); + else + val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TIORH); + + return (is_channel_en && (val & RZ_MTU3_TIOR_OC_IOA)); +} + +static int rz_mtu3_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip); + struct rz_mtu3_channel *ch; + u32 ch_index; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + if (!rz_mtu3_pwm->user_count[ch_index] && !rz_mtu3_request_channel(ch)) + return -EBUSY; + + mutex_lock(&rz_mtu3_pwm->lock); + rz_mtu3_pwm->user_count[ch_index]++; + mutex_unlock(&rz_mtu3_pwm->lock); + + return 0; +} + +static void rz_mtu3_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip); + struct rz_mtu3_channel *ch; + u32 ch_index; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + + mutex_lock(&rz_mtu3_pwm->lock); + rz_mtu3_pwm->user_count[ch_index]--; + mutex_unlock(&rz_mtu3_pwm->lock); + + if (!rz_mtu3_pwm->user_count[ch_index]) + rz_mtu3_release_channel(ch); +} + +static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + struct pwm_device *pwm) +{ + struct rz_mtu3_channel *ch; + u32 ch_index; + u8 val; + int rc; + + rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev); + if (rc) + return rc; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + val = (RZ_MTU3_TIOR_OC_1_TOGGLE << 4) | RZ_MTU3_TIOR_OC_0_H_COMP_MATCH; + + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_PWM_MODE_1); + if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORL, val); + else + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORH, val); + + if (rz_mtu3_pwm->user_count[ch_index] <= 1) + rz_mtu3_enable(ch); + + return 0; +} + +static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + struct pwm_device *pwm) +{ + struct rz_mtu3_channel *ch; + u32 ch_index; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + + /* Return to normal mode and disable output pins of MTU3 channel */ + if (rz_mtu3_pwm->user_count[ch_index] <= 1) + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_NORMAL); + + if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORL, RZ_MTU3_TIOR_OC_RETAIN); + else + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORH, RZ_MTU3_TIOR_OC_RETAIN); + + if (rz_mtu3_pwm->user_count[ch_index] <= 1) + rz_mtu3_disable(ch); + + pm_runtime_put_sync(rz_mtu3_pwm->chip.dev); +} + +static int rz_mtu3_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip); + struct rz_mtu3_channel *ch; + u8 prescale, val; + u32 ch_index; + u16 dc, pv; + u64 tmp; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + pm_runtime_get_sync(chip->dev); + state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm->hwpwm); + if (state->enabled) { + val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TCR); + prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val); + + if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) { + dc = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRD); + pv = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRC); + } else { + dc = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRB); + pv = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRA); + } + + tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale); + state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate); + } else { + /* If the PWM is disabled, use the cached value. */ + prescale = rz_mtu3_pwm->prescale[ch_index]; + dc = rz_mtu3_pwm->duty_cycle[pwm->hwpwm]; + } + + tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale); + state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate); + state->polarity = PWM_POLARITY_NORMAL; + pm_runtime_put(chip->dev); + + return 0; +} + +static int rz_mtu3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip); + struct rz_mtu3_channel *ch; + unsigned long pv, dc; + u64 period_cycles; + u64 duty_cycles; + u32 ch_index; + u8 prescale; + int err; + u8 val; + + /* + * Refuse clk rates > 1 GHz to prevent overflowing the following + * calculation. + */ + if (rz_mtu3_pwm->rate > NSEC_PER_SEC) + return -EINVAL; + + ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm); + ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch); + period_cycles = mul_u64_u32_div(state->period, rz_mtu3_pwm->rate, + NSEC_PER_SEC); + prescale = rz_mtu3_pwm_calculate_prescale(rz_mtu3_pwm, period_cycles); + + if (period_cycles >> (2 * prescale) <= U16_MAX) + pv = period_cycles >> (2 * prescale); + else + pv = U16_MAX; + + duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm->rate, + NSEC_PER_SEC); + if (duty_cycles >> (2 * prescale) <= U16_MAX) + dc = duty_cycles >> (2 * prescale); + else + dc = U16_MAX; + + /* + * Store the duty cycle/prescale for future reference in cases where the + * corresponding registers can't be read (i.e. when the PWM is disabled). + */ + rz_mtu3_pwm->prescale[ch_index] = prescale; + rz_mtu3_pwm->duty_cycle[pwm->hwpwm] = dc; + + /* + * If the PWM channel is disabled, make sure to turn on the clock + * before writing the register. + */ + if (!pwm->state.enabled) { + err = pm_runtime_resume_and_get(chip->dev); + if (err) + return err; + } + + val = RZ_MTU3_TCR_CKEG_RISING | prescale; + if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) { + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR, + RZ_MTU3_TCR_CCLR_TGRC | val); + rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRD, dc); + rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRC, pv); + } else { + rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR, + RZ_MTU3_TCR_CCLR_TGRA | val); + rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRB, dc); + rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRA, pv); + } + + /* If the PWM is not enabled, turn the clock off again to save power. */ + if (!pwm->state.enabled) + pm_runtime_put(chip->dev); + + return 0; +} + +static int rz_mtu3_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip); + bool enabled = pwm->state.enabled; + int ret; + + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + if (!state->enabled) { + if (enabled) + rz_mtu3_pwm_disable(rz_mtu3_pwm, pwm); + + return 0; + } + + ret = rz_mtu3_pwm_config(chip, pwm, state); + if (ret) + return ret; + + if (!enabled) + ret = rz_mtu3_pwm_enable(rz_mtu3_pwm, pwm); + + return ret; +} + +static const struct pwm_ops rz_mtu3_pwm_ops = { + .request = rz_mtu3_pwm_request, + .free = rz_mtu3_pwm_free, + .get_state = rz_mtu3_pwm_get_state, + .apply = rz_mtu3_pwm_apply, + .owner = THIS_MODULE, +}; + +static int rz_mtu3_pwm_pm_runtime_suspend(struct device *dev) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev); + + clk_disable_unprepare(rz_mtu3_pwm->clk); + + return 0; +} + +static int rz_mtu3_pwm_pm_runtime_resume(struct device *dev) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev); + + clk_prepare_enable(rz_mtu3_pwm->clk); + + return 0; +} + +static DEFINE_RUNTIME_DEV_PM_OPS(rz_mtu3_pwm_pm_ops, + rz_mtu3_pwm_pm_runtime_suspend, + rz_mtu3_pwm_pm_runtime_resume, NULL); + +static void rz_mtu3_pwm_pm_disable(void *data) +{ + struct rz_mtu3_pwm_chip *rz_mtu3_pwm = data; + + pm_runtime_disable(rz_mtu3_pwm->chip.dev); + pm_runtime_set_suspended(rz_mtu3_pwm->chip.dev); +} + +static int rz_mtu3_pwm_probe(struct platform_device *pdev) +{ + struct rz_mtu3 *ddata = dev_get_drvdata(pdev->dev.parent); + struct rz_mtu3_pwm_chip *rz_mtu3_pwm; + struct device *dev = &pdev->dev; + int num_pwm_hw_ch = 0; + unsigned int i; + int ret; + + rz_mtu3_pwm = devm_kzalloc(&pdev->dev, sizeof(*rz_mtu3_pwm), GFP_KERNEL); + if (!rz_mtu3_pwm) + return -ENOMEM; + + rz_mtu3_pwm->clk = ddata->clk; + rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk); + for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) { + if (i == RZ_MTU5 || i == RZ_MTU8) + continue; + + rz_mtu3_pwm->ch[num_pwm_hw_ch] = &ddata->channels[i]; + rz_mtu3_pwm->ch[num_pwm_hw_ch]->dev = dev; + num_pwm_hw_ch++; + } + + mutex_init(&rz_mtu3_pwm->lock); + platform_set_drvdata(pdev, rz_mtu3_pwm); + clk_prepare_enable(rz_mtu3_pwm->clk); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + ret = devm_add_action_or_reset(&pdev->dev, + rz_mtu3_pwm_pm_disable, + rz_mtu3_pwm); + if (ret < 0) + goto disable_clock; + + rz_mtu3_pwm->chip.dev = &pdev->dev; + rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops; + rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_MODE1_CHANNELS; + ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip); + if (ret) { + dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n"); + goto disable_clock; + } + + return 0; + +disable_clock: + clk_disable_unprepare(rz_mtu3_pwm->clk); + return ret; +} + +static struct platform_driver rz_mtu3_pwm_driver = { + .driver = { + .name = "pwm-rz-mtu3", + .pm = pm_ptr(&rz_mtu3_pwm_pm_ops), + }, + .probe = rz_mtu3_pwm_probe, +}; +module_platform_driver(rz_mtu3_pwm_driver); + +MODULE_AUTHOR("Biju Das <biju.das.jz@xxxxxxxxxxxxxx>"); +MODULE_ALIAS("platform:pwm-rz-mtu3"); +MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a PWM Timer Driver"); +MODULE_LICENSE("GPL"); -- 2.25.1