| Message ID | 20230522171449.688814-1-biju.das.jz@bp.renesas.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | [v17] pwm: Add Renesas RZ/G2L MTU3a PWM driver | expand |
Hi Uwe, Gentle ping. Are you happy with this patch? Cheers, Biju > -----Original Message----- > From: Biju Das <biju.das.jz@bp.renesas.com> > Sent: Monday, May 22, 2023 6:15 PM > To: Thierry Reding <thierry.reding@gmail.com> > Cc: Biju Das <biju.das.jz@bp.renesas.com>; Uwe Kleine-König <u.kleine- > koenig@pengutronix.de>; linux-pwm@vger.kernel.org; Geert Uytterhoeven > <geert+renesas@glider.be>; Prabhakar Mahadev Lad <prabhakar.mahadev- > lad.rj@bp.renesas.com>; linux-renesas-soc@vger.kernel.org > Subject: [PATCH v17] pwm: Add Renesas RZ/G2L MTU3a PWM driver > > The RZ/G2L Multi-Function Timer Pulse Unit 3 (a.k.a MTU3a) uses one > counter and two match components to configure duty_cycle and period to > generate PWM output waveform. > > Add basic support for RZ/G2L MTU3a PWM driver by creating separate PWM > channels for each IOs. > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > --- > v16->v17: > * Added a comment related to supported prescalar values in rz_mtu3_pwm_ > calculate_prescale(). > * Replaced pm_runtime_get_sync->pm_runtime_resume_and_get and > propogated > the error. > * Improved the logic in rz_mtu3_pwm_calculate_pv_or_dc() by using > min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX); > * Updated rz_mtu3_pwm_get_state() by moving duty > period check > inside the top if block. > v15->v16: > * Fixed extra space around hwpwm check on rz_mtu3_get_channel(). > * Dropped redundant is_channel_en check on rz_mtu3_pwm_is_ch_enabled(). > * Replaced channel->base_pwm_number in struct rz_mtu3_channel_io_map. > * Added comment for channel_map. > * Dropped setting normal mode in rz_mtu3_pwm_disable(). > * Replaced ddata->parent_ddata in probe() > * Added support for modifying prescalar, if other PWM is off or handle > it, if current prescale value is less than the one we want to set. > * Added below helper functions rz_mtu3_pwm_calculate_pv_or_dc() and > rz_mtu3_pwm_{read,write}_tgr_registers to simplify the code. > v14->v15: > * Updated copyright header and Limitations section > * Moved register definitions to <linux/mfd/rz-mtu3.h> > * Introduced new mapping table struct rz_mtu3_channel_io_map to hold > the > index of the lowest PWM and the number of PWMs handled by the HW > channel. > * Introduced struct rz_mtu3_pwm_channel to hold mtu3 channel data and > mapping table. > * Replaced rz_mtu3_get_hw_channel->rz_mtu3_get_channel and channel- > >hwpwm. > The rz_mtu3_get_channel() returns struct rz_mtu3_pwm_channel* > * Dropped rz_mtu3_pwm_is_second_channel() as same can be obtained > directly > with new mapping (ie, priv->map->channel == pwm->hwpwm) > * Replaced ch_index->ch throughout and used "priv - rz_mtu3_pwm- > >channel_data" > to find ch and dropped rz_mtu3_get_hw_channel_index(). > * Optimized rz_mtu3_pwm_is_ch_enabled() by exit early, if is_channel_en > is false. > * Updated rz_mtu3_pwm_request() and added comments. > * Introduced a bug in the driver by introducing enable_count, which > increment/ > decrement during enable()/disable(). > * Reduced variable scope in rz_mtu3_pwm_get_state() by moving most of > variables > inside the if statement. > * Updated probe() to assign the struct rz_mtu3_pwm_channel values. > v13->v14: > * Updated commit description > * Updated Limitations section. > * Replaced the macros RZ_MTU*->RZ_MTU3_CHAN_* in probe() > * Fixed a kernel crash in error path by moving rz_mtu3_pwm->chip.dev > before > devm_add_action_or_reset() > * Added pm_runtime_idle() and simplified error paths for > devm_add_action_or_reset() > and devm_pwmchip_add(). > v12->v13: > * Updated commit description > * Moved RZ_MTU3_TMDR1_MD_* macros to rz_mtu3.h > * Updated Limitations section. > * Removed PWM mode1 references from the driver. > * Dropped prescale and duty_cycle from struct rz_mtu3_pwm_chip. > * Replaced rz_mtu3_pwm_mode1_num_ios->rz_mtu3_hw_channel_ios. > * Avoided race condition in rz_mtu3_pwm_request()/rz_mtu3_pwm_free(). > * Updated get_state() by adding dc > pv check and added a comment about > overflow condition. > * Moved overflow condition check from config->probe() > * Replaced pm_runtime_resume_and_get with unconditional > pm_runtime_get_sync() > in config() > * Added error check for clk_prepare_enable() in probe() and propagating > error > to the caller for pm_runtime_resume() > * clk_get_rate() is called after enabling the clock and > clk_rate_exclusive_put() > 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 | 551 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 563 insertions(+) > create mode 100644 drivers/pwm/pwm-rz-mtu3.c > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index > 8df861b1f4a3..ac0517b51540 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -493,6 +493,17 @@ 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 19899b912e00..68b7a15c2ca5 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -45,6 +45,7 @@ obj-$(CONFIG_PWM_RASPBERRYPI_POE) += pwm-raspberrypi- > poe.o > obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o > obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o > obj-$(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..bed8bd671e37 > --- /dev/null > +++ b/drivers/pwm/pwm-rz-mtu3.c > @@ -0,0 +1,551 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Renesas RZ/G2L MTU3a PWM Timer driver > + * > + * Copyright (C) 2023 Renesas Electronics Corporation > + * > + * Hardware manual for this IP can be found here > + * > +https://www.renesas.com/eu/en/document/mah/rzg2l-group-rzg2lc-group-use > +rs-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. > + * - HW uses one counter and two match components to configure > duty_cycle > + * and period. > + * - Multi-Function Timer Pulse Unit (a.k.a MTU) has 7 HW channels for > PWM > + * operations. (The channels are MTU{0..4, 6, 7}.) > + * - MTU{1, 2} channels have a single IO, whereas all other HW channels > have > + * 2 IOs. > + * - Each IO is modelled as an independent PWM channel. > + * - rz_mtu3_channel_io_map table is used to map the PWM channel to the > + * corresponding HW channel as there are difference in number of IOs > + * between HW channels. > + */ > + > +#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_MAX_PWM_CHANNELS 12 > +#define RZ_MTU3_MAX_HW_CHANNELS 7 > + > +/** > + * struct rz_mtu3_channel_io_map - MTU3 pwm channel map > + * > + * @base_pwm_number: First PWM of a channel > + * @num: number of IOs on the HW channel. > + */ > +struct rz_mtu3_channel_io_map { > + u8 base_pwm_number; > + u8 num_channel_ios; > +}; > + > +/** > + * struct rz_mtu3_pwm_channel - MTU3 pwm channel data > + * > + * @mtu: MTU3 channel data > + * @map: MTU3 pwm channel map > + */ > +struct rz_mtu3_pwm_channel { > + struct rz_mtu3_channel *mtu; > + const struct rz_mtu3_channel_io_map *map; }; > + > +/** > + * 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 > + * @enable_count: MTU3 enable count > + * @prescale: MTU3 prescale > + * @channel_data: MTU3 pwm channel data */ > + > +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_CHANNELS]; > + u32 enable_count[RZ_MTU3_MAX_HW_CHANNELS]; > + u8 prescale[RZ_MTU3_MAX_HW_CHANNELS]; > + struct rz_mtu3_pwm_channel channel_data[RZ_MTU3_MAX_HW_CHANNELS]; > +}; > + > +/* > + * The MTU channels are {0..4, 6, 7} and the number of IO on MTU1 > + * and MTU2 channel is 1 compared to 2 on others. > + */ > +static const struct rz_mtu3_channel_io_map channel_map[] = { > + { 0, 2 }, { 2, 1 }, { 3, 1 }, { 4, 2 }, { 6, 2 }, { 8, 2 }, { 10, > 2 } > +}; > + > +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 void rz_mtu3_pwm_read_tgr_registers(struct rz_mtu3_pwm_channel > *priv, > + u16 reg_pv_offset, u16 *pv_val, > + u16 reg_dc_offset, u16 *dc_val) { > + *pv_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_pv_offset); > + *dc_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_dc_offset); } > + > +static void rz_mtu3_pwm_write_tgr_registers(struct rz_mtu3_pwm_channel > *priv, > + u16 reg_pv_offset, u16 pv_val, > + u16 reg_dc_offset, u16 dc_val) { > + rz_mtu3_16bit_ch_write(priv->mtu, reg_pv_offset, pv_val); > + rz_mtu3_16bit_ch_write(priv->mtu, reg_dc_offset, dc_val); } > + > +static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip > *rz_mtu3, > + u64 period_cycles) > +{ > + u32 prescaled_period_cycles; > + u8 prescale; > + > + /* > + * Supported prescale values are 1, 4, 16 and 64. > + * TODO: Support prescale values 2, 8, 32, 256 and 1024. > + */ > + 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_pwm_channel * > +rz_mtu3_get_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 hwpwm) { > + struct rz_mtu3_pwm_channel *priv = rz_mtu3_pwm->channel_data; > + unsigned int ch; > + > + for (ch = 0; ch < RZ_MTU3_MAX_HW_CHANNELS; ch++, priv++) { > + if (priv->map->base_pwm_number + priv->map->num_channel_ios > > hwpwm) > + break; > + } > + > + return priv; > +} > + > +static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip > *rz_mtu3_pwm, > + u32 hwpwm) > +{ > + struct rz_mtu3_pwm_channel *priv; > + bool is_channel_en; > + u8 val; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, hwpwm); > + is_channel_en = rz_mtu3_is_enabled(priv->mtu); > + if (!is_channel_en) > + return false; > + > + if (priv->map->base_pwm_number == hwpwm) > + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORH); > + else > + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORL); > + > + return val & RZ_MTU3_TIOR_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_pwm_channel *priv; > + bool is_mtu3_channel_available; > + u32 ch; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + ch = priv - rz_mtu3_pwm->channel_data; > + > + mutex_lock(&rz_mtu3_pwm->lock); > + /* > + * Each channel must be requested only once, so if the channel > + * serves two PWMs and the other is already requested, skip over > + * rz_mtu3_request_channel() > + */ > + if (!rz_mtu3_pwm->user_count[ch]) { > + is_mtu3_channel_available = rz_mtu3_request_channel(priv- > >mtu); > + if (!is_mtu3_channel_available) { > + mutex_unlock(&rz_mtu3_pwm->lock); > + return -EBUSY; > + } > + } > + > + rz_mtu3_pwm->user_count[ch]++; > + 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_pwm_channel *priv; > + u32 ch; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + ch = priv - rz_mtu3_pwm->channel_data; > + > + mutex_lock(&rz_mtu3_pwm->lock); > + rz_mtu3_pwm->user_count[ch]--; > + if (!rz_mtu3_pwm->user_count[ch]) > + rz_mtu3_release_channel(priv->mtu); > + > + mutex_unlock(&rz_mtu3_pwm->lock); > +} > + > +static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, > + struct pwm_device *pwm) > +{ > + struct rz_mtu3_pwm_channel *priv; > + u32 ch; > + u8 val; > + int rc; > + > + rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev); > + if (rc) > + return rc; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + ch = priv - rz_mtu3_pwm->channel_data; > + val = RZ_MTU3_TIOR_OC_IOB_TOGGLE | > RZ_MTU3_TIOR_OC_IOA_H_COMP_MATCH; > + > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TMDR1, > RZ_MTU3_TMDR1_MD_PWMMODE1); > + if (priv->map->base_pwm_number == pwm->hwpwm) > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, val); > + else > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, val); > + > + mutex_lock(&rz_mtu3_pwm->lock); > + if (!rz_mtu3_pwm->enable_count[ch]) > + rz_mtu3_enable(priv->mtu); > + > + rz_mtu3_pwm->enable_count[ch]++; > + mutex_unlock(&rz_mtu3_pwm->lock); > + > + return 0; > +} > + > +static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, > + struct pwm_device *pwm) > +{ > + struct rz_mtu3_pwm_channel *priv; > + u32 ch; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + ch = priv - rz_mtu3_pwm->channel_data; > + > + /* Disable output pins of MTU3 channel */ > + if (priv->map->base_pwm_number == pwm->hwpwm) > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, > RZ_MTU3_TIOR_OC_RETAIN); > + else > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, > +RZ_MTU3_TIOR_OC_RETAIN); > + > + mutex_lock(&rz_mtu3_pwm->lock); > + rz_mtu3_pwm->enable_count[ch]--; > + if (!rz_mtu3_pwm->enable_count[ch]) > + rz_mtu3_disable(priv->mtu); > + > + mutex_unlock(&rz_mtu3_pwm->lock); > + > + 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); > + int rc; > + > + rc = pm_runtime_resume_and_get(chip->dev); > + if (rc) > + return rc; > + > + state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm- > >hwpwm); > + if (state->enabled) { > + struct rz_mtu3_pwm_channel *priv; > + u8 prescale, val; > + u16 dc, pv; > + u64 tmp; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + if (priv->map->base_pwm_number == pwm->hwpwm) > + rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRA, > &pv, > + RZ_MTU3_TGRB, &dc); > + else > + rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRC, > &pv, > + RZ_MTU3_TGRD, &dc); > + > + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TCR); > + prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val); > + > + /* With prescale <= 7 and pv <= 0xffff this doesn't > overflow. */ > + tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale); > + state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate); > + tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale); > + state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm- > >rate); > + > + if (state->duty_cycle > state->period) > + state->duty_cycle = state->period; > + } > + > + state->polarity = PWM_POLARITY_NORMAL; > + pm_runtime_put(chip->dev); > + > + return 0; > +} > + > +static u16 rz_mtu3_pwm_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 > +prescale) { > + return min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX); > } > + > +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_pwm_channel *priv; > + u64 period_cycles; > + u64 duty_cycles; > + u8 prescale; > + u16 pv, dc; > + u8 val; > + u32 ch; > + > + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); > + ch = priv - rz_mtu3_pwm->channel_data; > + > + 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); > + > + /* > + * Prescalar is shared by multiple channels, so prescale can > + * NOT be modified when there are multiple channels in use with > + * different settings. Modify prescalar if other PWM is off or > handle > + * it, if current prescale value is less than the one we want to > set. > + */ > + if (rz_mtu3_pwm->enable_count[ch] > 1) { > + if (rz_mtu3_pwm->prescale[ch] > prescale) > + return -EBUSY; > + > + prescale = rz_mtu3_pwm->prescale[ch]; > + } > + > + pv = rz_mtu3_pwm_calculate_pv_or_dc(period_cycles, prescale); > + > + duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm- > >rate, > + NSEC_PER_SEC); > + dc = rz_mtu3_pwm_calculate_pv_or_dc(duty_cycles, prescale); > + > + /* > + * If the PWM channel is disabled, make sure to turn on the clock > + * before writing the register. > + */ > + if (!pwm->state.enabled) { > + int rc; > + > + rc = pm_runtime_resume_and_get(chip->dev); > + if (rc) > + return rc; > + } > + > + val = RZ_MTU3_TCR_CKEG_RISING | prescale; > + > + /* Counter must be stopped while updating TCR register */ > + if (rz_mtu3_pwm->prescale[ch] != prescale && rz_mtu3_pwm- > >enable_count[ch]) > + rz_mtu3_disable(priv->mtu); > + > + if (priv->map->base_pwm_number == pwm->hwpwm) { > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR, > + RZ_MTU3_TCR_CCLR_TGRA | val); > + rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRA, pv, > + RZ_MTU3_TGRB, dc); > + } else { > + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR, > + RZ_MTU3_TCR_CCLR_TGRC | val); > + rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRC, pv, > + RZ_MTU3_TGRD, dc); > + } > + > + if (rz_mtu3_pwm->prescale[ch] != prescale) { > + /* > + * Prescalar is shared by multiple channels, we cache the > + * prescalar value from first enabled channel and use the > same > + * value for both channels. > + */ > + rz_mtu3_pwm->prescale[ch] = prescale; > + > + if (rz_mtu3_pwm->enable_count[ch]) > + rz_mtu3_enable(priv->mtu); > + } > + > + /* 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; > + } > + > + mutex_lock(&rz_mtu3_pwm->lock); > + ret = rz_mtu3_pwm_config(chip, pwm, state); > + mutex_unlock(&rz_mtu3_pwm->lock); > + 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); > + > + return clk_prepare_enable(rz_mtu3_pwm->clk); > +} > + > +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; > + > + clk_rate_exclusive_put(rz_mtu3_pwm->clk); > + 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 *parent_ddata = dev_get_drvdata(pdev->dev.parent); > + struct rz_mtu3_pwm_chip *rz_mtu3_pwm; > + struct device *dev = &pdev->dev; > + unsigned int i, j = 0; > + 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 = parent_ddata->clk; > + > + for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) { > + if (i == RZ_MTU3_CHAN_5 || i == RZ_MTU3_CHAN_8) > + continue; > + > + rz_mtu3_pwm->channel_data[j].mtu = &parent_ddata- > >channels[i]; > + rz_mtu3_pwm->channel_data[j].mtu->dev = dev; > + rz_mtu3_pwm->channel_data[j].map = &channel_map[j]; > + j++; > + } > + > + mutex_init(&rz_mtu3_pwm->lock); > + platform_set_drvdata(pdev, rz_mtu3_pwm); > + ret = clk_prepare_enable(rz_mtu3_pwm->clk); > + if (ret) > + return dev_err_probe(dev, ret, "Clock enable failed\n"); > + > + clk_rate_exclusive_get(rz_mtu3_pwm->clk); > + > + rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk); > + /* > + * Refuse clk rates > 1 GHz to prevent overflow later for > computing > + * period and duty cycle. > + */ > + if (rz_mtu3_pwm->rate > NSEC_PER_SEC) { > + ret = -EINVAL; > + clk_rate_exclusive_put(rz_mtu3_pwm->clk); > + goto disable_clock; > + } > + > + pm_runtime_set_active(&pdev->dev); > + pm_runtime_enable(&pdev->dev); > + rz_mtu3_pwm->chip.dev = &pdev->dev; > + ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_pwm_pm_disable, > + rz_mtu3_pwm); > + if (ret < 0) > + return ret; > + > + rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops; > + rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_CHANNELS; > + ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "failed to add PWM > chip\n"); > + > + pm_runtime_idle(&pdev->dev); > + > + 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@bp.renesas.com>"); > +MODULE_ALIAS("platform:pwm-rz-mtu3"); > +MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a PWM Timer Driver"); > +MODULE_LICENSE("GPL"); > > base-commit: 9f258af06b6268be8e960f63c3f66e88bdbbbdb0 > prerequisite-patch-id: 7d5c55db908971d16a58eb46b25d42dfb0f680ec > prerequisite-patch-id: 6c15d33bb612750523d14af87a5cf9e6ff142540 > prerequisite-patch-id: e5e4d86a0a012a59f585b84ce7ae0d3f047787dc > prerequisite-patch-id: d62b4e1326f1518fd30eb98a37bfb4998573979a > prerequisite-patch-id: 15bf63b610cab275387a2bbee7ab2a0a48414f75 > -- > 2.25.1
Hello, On Mon, May 22, 2023 at 06:14:49PM +0100, Biju Das wrote: > base-commit: 9f258af06b6268be8e960f63c3f66e88bdbbbdb0 > prerequisite-patch-id: 7d5c55db908971d16a58eb46b25d42dfb0f680ec > prerequisite-patch-id: 6c15d33bb612750523d14af87a5cf9e6ff142540 > prerequisite-patch-id: e5e4d86a0a012a59f585b84ce7ae0d3f047787dc > prerequisite-patch-id: d62b4e1326f1518fd30eb98a37bfb4998573979a > prerequisite-patch-id: 15bf63b610cab275387a2bbee7ab2a0a48414f75 My working copy doesn't contain 9f258af06b6268be8e960f63c3f66e88bdbbbdb0, so I wonder what is the base you used here. Also the other prerequisite patches are unclear to me and I didn't find them[1]. I assume it's stuff around 654c293e1687 mfd: Add Renesas RZ/G2L MTU3a core driver (which is in v6.4-rc1)? I recommend duplicating this information in human readable form in the cover letter (or below the --- if it's only a single patch). So this patch was probably not tested by the build bots. Otherwise I think this is good enough to go in now, so: Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks Uwe [1] git log -p v6.2..next/master | git patch-id | grep 6c15d33bb612750523d14af87a5cf9e6ff142540
Hi Uwe, Thanks for the feedback. > Subject: Re: [PATCH v17] pwm: Add Renesas RZ/G2L MTU3a PWM driver > > Hello, > > On Mon, May 22, 2023 at 06:14:49PM +0100, Biju Das wrote: > > base-commit: 9f258af06b6268be8e960f63c3f66e88bdbbbdb0 > > prerequisite-patch-id: 7d5c55db908971d16a58eb46b25d42dfb0f680ec > > prerequisite-patch-id: 6c15d33bb612750523d14af87a5cf9e6ff142540 > > prerequisite-patch-id: e5e4d86a0a012a59f585b84ce7ae0d3f047787dc > > prerequisite-patch-id: d62b4e1326f1518fd30eb98a37bfb4998573979a > > prerequisite-patch-id: 15bf63b610cab275387a2bbee7ab2a0a48414f75 > > My working copy doesn't contain > 9f258af06b6268be8e960f63c3f66e88bdbbbdb0, so I wonder what is the base > you used here. Also the other prerequisite patches are unclear to me and > I didn't find them[1]. I assume it's stuff around > > 654c293e1687 mfd: Add Renesas RZ/G2L MTU3a core driver Yes, base-commit: 9f258af06b62 is based on Linux-next as PWM git [2], does not have the commit 654c293e1687 'mfd: Add Renesas RZ/G2L MTU3a core driver' Other patches are not in mainline( config, device tree and CI related). 0001-CI-Add-CI-build.patch 0002-renesas-defconfig.patch 0003-Enable-MTU3.patch 0004-defconfig-Enable-MTU3.patch 0005-renesas_defconfig-Enable-MTU3.patch [2] https://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm.git/log/?qt=grep&q=biju.das&h=for-next > > (which is in v6.4-rc1)? I recommend duplicating this information in > human readable form in the cover letter (or below the --- if it's only a > single patch). > > So this patch was probably not tested by the build bots. OK, Will resend with base-commit for mainline 6.4-rc1. Will drop other prerequisite patches. Cheers, Biju > Otherwise I think this is good enough to go in now, so: > > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > > Thanks > Uwe >
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 8df861b1f4a3..ac0517b51540 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -493,6 +493,17 @@ 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 19899b912e00..68b7a15c2ca5 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_PWM_RASPBERRYPI_POE) += pwm-raspberrypi-poe.o obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o obj-$(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..bed8bd671e37 --- /dev/null +++ b/drivers/pwm/pwm-rz-mtu3.c @@ -0,0 +1,551 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L MTU3a PWM Timer driver + * + * Copyright (C) 2023 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. + * - HW uses one counter and two match components to configure duty_cycle + * and period. + * - Multi-Function Timer Pulse Unit (a.k.a MTU) has 7 HW channels for PWM + * operations. (The channels are MTU{0..4, 6, 7}.) + * - MTU{1, 2} channels have a single IO, whereas all other HW channels have + * 2 IOs. + * - Each IO is modelled as an independent PWM channel. + * - rz_mtu3_channel_io_map table is used to map the PWM channel to the + * corresponding HW channel as there are difference in number of IOs + * between HW channels. + */ + +#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_MAX_PWM_CHANNELS 12 +#define RZ_MTU3_MAX_HW_CHANNELS 7 + +/** + * struct rz_mtu3_channel_io_map - MTU3 pwm channel map + * + * @base_pwm_number: First PWM of a channel + * @num: number of IOs on the HW channel. + */ +struct rz_mtu3_channel_io_map { + u8 base_pwm_number; + u8 num_channel_ios; +}; + +/** + * struct rz_mtu3_pwm_channel - MTU3 pwm channel data + * + * @mtu: MTU3 channel data + * @map: MTU3 pwm channel map + */ +struct rz_mtu3_pwm_channel { + struct rz_mtu3_channel *mtu; + const struct rz_mtu3_channel_io_map *map; +}; + +/** + * 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 + * @enable_count: MTU3 enable count + * @prescale: MTU3 prescale + * @channel_data: MTU3 pwm channel data + */ + +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_CHANNELS]; + u32 enable_count[RZ_MTU3_MAX_HW_CHANNELS]; + u8 prescale[RZ_MTU3_MAX_HW_CHANNELS]; + struct rz_mtu3_pwm_channel channel_data[RZ_MTU3_MAX_HW_CHANNELS]; +}; + +/* + * The MTU channels are {0..4, 6, 7} and the number of IO on MTU1 + * and MTU2 channel is 1 compared to 2 on others. + */ +static const struct rz_mtu3_channel_io_map channel_map[] = { + { 0, 2 }, { 2, 1 }, { 3, 1 }, { 4, 2 }, { 6, 2 }, { 8, 2 }, { 10, 2 } +}; + +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 void rz_mtu3_pwm_read_tgr_registers(struct rz_mtu3_pwm_channel *priv, + u16 reg_pv_offset, u16 *pv_val, + u16 reg_dc_offset, u16 *dc_val) +{ + *pv_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_pv_offset); + *dc_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_dc_offset); +} + +static void rz_mtu3_pwm_write_tgr_registers(struct rz_mtu3_pwm_channel *priv, + u16 reg_pv_offset, u16 pv_val, + u16 reg_dc_offset, u16 dc_val) +{ + rz_mtu3_16bit_ch_write(priv->mtu, reg_pv_offset, pv_val); + rz_mtu3_16bit_ch_write(priv->mtu, reg_dc_offset, dc_val); +} + +static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip *rz_mtu3, + u64 period_cycles) +{ + u32 prescaled_period_cycles; + u8 prescale; + + /* + * Supported prescale values are 1, 4, 16 and 64. + * TODO: Support prescale values 2, 8, 32, 256 and 1024. + */ + 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_pwm_channel * +rz_mtu3_get_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 hwpwm) +{ + struct rz_mtu3_pwm_channel *priv = rz_mtu3_pwm->channel_data; + unsigned int ch; + + for (ch = 0; ch < RZ_MTU3_MAX_HW_CHANNELS; ch++, priv++) { + if (priv->map->base_pwm_number + priv->map->num_channel_ios > hwpwm) + break; + } + + return priv; +} + +static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + u32 hwpwm) +{ + struct rz_mtu3_pwm_channel *priv; + bool is_channel_en; + u8 val; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, hwpwm); + is_channel_en = rz_mtu3_is_enabled(priv->mtu); + if (!is_channel_en) + return false; + + if (priv->map->base_pwm_number == hwpwm) + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORH); + else + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORL); + + return val & RZ_MTU3_TIOR_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_pwm_channel *priv; + bool is_mtu3_channel_available; + u32 ch; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + ch = priv - rz_mtu3_pwm->channel_data; + + mutex_lock(&rz_mtu3_pwm->lock); + /* + * Each channel must be requested only once, so if the channel + * serves two PWMs and the other is already requested, skip over + * rz_mtu3_request_channel() + */ + if (!rz_mtu3_pwm->user_count[ch]) { + is_mtu3_channel_available = rz_mtu3_request_channel(priv->mtu); + if (!is_mtu3_channel_available) { + mutex_unlock(&rz_mtu3_pwm->lock); + return -EBUSY; + } + } + + rz_mtu3_pwm->user_count[ch]++; + 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_pwm_channel *priv; + u32 ch; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + ch = priv - rz_mtu3_pwm->channel_data; + + mutex_lock(&rz_mtu3_pwm->lock); + rz_mtu3_pwm->user_count[ch]--; + if (!rz_mtu3_pwm->user_count[ch]) + rz_mtu3_release_channel(priv->mtu); + + mutex_unlock(&rz_mtu3_pwm->lock); +} + +static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + struct pwm_device *pwm) +{ + struct rz_mtu3_pwm_channel *priv; + u32 ch; + u8 val; + int rc; + + rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev); + if (rc) + return rc; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + ch = priv - rz_mtu3_pwm->channel_data; + val = RZ_MTU3_TIOR_OC_IOB_TOGGLE | RZ_MTU3_TIOR_OC_IOA_H_COMP_MATCH; + + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_PWMMODE1); + if (priv->map->base_pwm_number == pwm->hwpwm) + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, val); + else + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, val); + + mutex_lock(&rz_mtu3_pwm->lock); + if (!rz_mtu3_pwm->enable_count[ch]) + rz_mtu3_enable(priv->mtu); + + rz_mtu3_pwm->enable_count[ch]++; + mutex_unlock(&rz_mtu3_pwm->lock); + + return 0; +} + +static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, + struct pwm_device *pwm) +{ + struct rz_mtu3_pwm_channel *priv; + u32 ch; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + ch = priv - rz_mtu3_pwm->channel_data; + + /* Disable output pins of MTU3 channel */ + if (priv->map->base_pwm_number == pwm->hwpwm) + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, RZ_MTU3_TIOR_OC_RETAIN); + else + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, RZ_MTU3_TIOR_OC_RETAIN); + + mutex_lock(&rz_mtu3_pwm->lock); + rz_mtu3_pwm->enable_count[ch]--; + if (!rz_mtu3_pwm->enable_count[ch]) + rz_mtu3_disable(priv->mtu); + + mutex_unlock(&rz_mtu3_pwm->lock); + + 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); + int rc; + + rc = pm_runtime_resume_and_get(chip->dev); + if (rc) + return rc; + + state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm->hwpwm); + if (state->enabled) { + struct rz_mtu3_pwm_channel *priv; + u8 prescale, val; + u16 dc, pv; + u64 tmp; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + if (priv->map->base_pwm_number == pwm->hwpwm) + rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRA, &pv, + RZ_MTU3_TGRB, &dc); + else + rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRC, &pv, + RZ_MTU3_TGRD, &dc); + + val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TCR); + prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val); + + /* With prescale <= 7 and pv <= 0xffff this doesn't overflow. */ + tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale); + state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate); + tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale); + state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate); + + if (state->duty_cycle > state->period) + state->duty_cycle = state->period; + } + + state->polarity = PWM_POLARITY_NORMAL; + pm_runtime_put(chip->dev); + + return 0; +} + +static u16 rz_mtu3_pwm_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 prescale) +{ + return min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX); +} + +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_pwm_channel *priv; + u64 period_cycles; + u64 duty_cycles; + u8 prescale; + u16 pv, dc; + u8 val; + u32 ch; + + priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm); + ch = priv - rz_mtu3_pwm->channel_data; + + 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); + + /* + * Prescalar is shared by multiple channels, so prescale can + * NOT be modified when there are multiple channels in use with + * different settings. Modify prescalar if other PWM is off or handle + * it, if current prescale value is less than the one we want to set. + */ + if (rz_mtu3_pwm->enable_count[ch] > 1) { + if (rz_mtu3_pwm->prescale[ch] > prescale) + return -EBUSY; + + prescale = rz_mtu3_pwm->prescale[ch]; + } + + pv = rz_mtu3_pwm_calculate_pv_or_dc(period_cycles, prescale); + + duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm->rate, + NSEC_PER_SEC); + dc = rz_mtu3_pwm_calculate_pv_or_dc(duty_cycles, prescale); + + /* + * If the PWM channel is disabled, make sure to turn on the clock + * before writing the register. + */ + if (!pwm->state.enabled) { + int rc; + + rc = pm_runtime_resume_and_get(chip->dev); + if (rc) + return rc; + } + + val = RZ_MTU3_TCR_CKEG_RISING | prescale; + + /* Counter must be stopped while updating TCR register */ + if (rz_mtu3_pwm->prescale[ch] != prescale && rz_mtu3_pwm->enable_count[ch]) + rz_mtu3_disable(priv->mtu); + + if (priv->map->base_pwm_number == pwm->hwpwm) { + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR, + RZ_MTU3_TCR_CCLR_TGRA | val); + rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRA, pv, + RZ_MTU3_TGRB, dc); + } else { + rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR, + RZ_MTU3_TCR_CCLR_TGRC | val); + rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRC, pv, + RZ_MTU3_TGRD, dc); + } + + if (rz_mtu3_pwm->prescale[ch] != prescale) { + /* + * Prescalar is shared by multiple channels, we cache the + * prescalar value from first enabled channel and use the same + * value for both channels. + */ + rz_mtu3_pwm->prescale[ch] = prescale; + + if (rz_mtu3_pwm->enable_count[ch]) + rz_mtu3_enable(priv->mtu); + } + + /* 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; + } + + mutex_lock(&rz_mtu3_pwm->lock); + ret = rz_mtu3_pwm_config(chip, pwm, state); + mutex_unlock(&rz_mtu3_pwm->lock); + 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); + + return clk_prepare_enable(rz_mtu3_pwm->clk); +} + +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; + + clk_rate_exclusive_put(rz_mtu3_pwm->clk); + 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 *parent_ddata = dev_get_drvdata(pdev->dev.parent); + struct rz_mtu3_pwm_chip *rz_mtu3_pwm; + struct device *dev = &pdev->dev; + unsigned int i, j = 0; + 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 = parent_ddata->clk; + + for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) { + if (i == RZ_MTU3_CHAN_5 || i == RZ_MTU3_CHAN_8) + continue; + + rz_mtu3_pwm->channel_data[j].mtu = &parent_ddata->channels[i]; + rz_mtu3_pwm->channel_data[j].mtu->dev = dev; + rz_mtu3_pwm->channel_data[j].map = &channel_map[j]; + j++; + } + + mutex_init(&rz_mtu3_pwm->lock); + platform_set_drvdata(pdev, rz_mtu3_pwm); + ret = clk_prepare_enable(rz_mtu3_pwm->clk); + if (ret) + return dev_err_probe(dev, ret, "Clock enable failed\n"); + + clk_rate_exclusive_get(rz_mtu3_pwm->clk); + + rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk); + /* + * Refuse clk rates > 1 GHz to prevent overflow later for computing + * period and duty cycle. + */ + if (rz_mtu3_pwm->rate > NSEC_PER_SEC) { + ret = -EINVAL; + clk_rate_exclusive_put(rz_mtu3_pwm->clk); + goto disable_clock; + } + + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + rz_mtu3_pwm->chip.dev = &pdev->dev; + ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_pwm_pm_disable, + rz_mtu3_pwm); + if (ret < 0) + return ret; + + rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops; + rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_CHANNELS; + ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip); + if (ret) + return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n"); + + pm_runtime_idle(&pdev->dev); + + 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@bp.renesas.com>"); +MODULE_ALIAS("platform:pwm-rz-mtu3"); +MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a PWM Timer Driver"); +MODULE_LICENSE("GPL");
The RZ/G2L Multi-Function Timer Pulse Unit 3 (a.k.a MTU3a) uses one counter and two match components to configure duty_cycle and period to generate PWM output waveform. Add basic support for RZ/G2L MTU3a PWM driver by creating separate PWM channels for each IOs. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> --- v16->v17: * Added a comment related to supported prescalar values in rz_mtu3_pwm_ calculate_prescale(). * Replaced pm_runtime_get_sync->pm_runtime_resume_and_get and propogated the error. * Improved the logic in rz_mtu3_pwm_calculate_pv_or_dc() by using min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX); * Updated rz_mtu3_pwm_get_state() by moving duty > period check inside the top if block. v15->v16: * Fixed extra space around hwpwm check on rz_mtu3_get_channel(). * Dropped redundant is_channel_en check on rz_mtu3_pwm_is_ch_enabled(). * Replaced channel->base_pwm_number in struct rz_mtu3_channel_io_map. * Added comment for channel_map. * Dropped setting normal mode in rz_mtu3_pwm_disable(). * Replaced ddata->parent_ddata in probe() * Added support for modifying prescalar, if other PWM is off or handle it, if current prescale value is less than the one we want to set. * Added below helper functions rz_mtu3_pwm_calculate_pv_or_dc() and rz_mtu3_pwm_{read,write}_tgr_registers to simplify the code. v14->v15: * Updated copyright header and Limitations section * Moved register definitions to <linux/mfd/rz-mtu3.h> * Introduced new mapping table struct rz_mtu3_channel_io_map to hold the index of the lowest PWM and the number of PWMs handled by the HW channel. * Introduced struct rz_mtu3_pwm_channel to hold mtu3 channel data and mapping table. * Replaced rz_mtu3_get_hw_channel->rz_mtu3_get_channel and channel->hwpwm. The rz_mtu3_get_channel() returns struct rz_mtu3_pwm_channel* * Dropped rz_mtu3_pwm_is_second_channel() as same can be obtained directly with new mapping (ie, priv->map->channel == pwm->hwpwm) * Replaced ch_index->ch throughout and used "priv - rz_mtu3_pwm->channel_data" to find ch and dropped rz_mtu3_get_hw_channel_index(). * Optimized rz_mtu3_pwm_is_ch_enabled() by exit early, if is_channel_en is false. * Updated rz_mtu3_pwm_request() and added comments. * Introduced a bug in the driver by introducing enable_count, which increment/ decrement during enable()/disable(). * Reduced variable scope in rz_mtu3_pwm_get_state() by moving most of variables inside the if statement. * Updated probe() to assign the struct rz_mtu3_pwm_channel values. v13->v14: * Updated commit description * Updated Limitations section. * Replaced the macros RZ_MTU*->RZ_MTU3_CHAN_* in probe() * Fixed a kernel crash in error path by moving rz_mtu3_pwm->chip.dev before devm_add_action_or_reset() * Added pm_runtime_idle() and simplified error paths for devm_add_action_or_reset() and devm_pwmchip_add(). v12->v13: * Updated commit description * Moved RZ_MTU3_TMDR1_MD_* macros to rz_mtu3.h * Updated Limitations section. * Removed PWM mode1 references from the driver. * Dropped prescale and duty_cycle from struct rz_mtu3_pwm_chip. * Replaced rz_mtu3_pwm_mode1_num_ios->rz_mtu3_hw_channel_ios. * Avoided race condition in rz_mtu3_pwm_request()/rz_mtu3_pwm_free(). * Updated get_state() by adding dc > pv check and added a comment about overflow condition. * Moved overflow condition check from config->probe() * Replaced pm_runtime_resume_and_get with unconditional pm_runtime_get_sync() in config() * Added error check for clk_prepare_enable() in probe() and propagating error to the caller for pm_runtime_resume() * clk_get_rate() is called after enabling the clock and clk_rate_exclusive_put() 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 | 551 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 563 insertions(+) create mode 100644 drivers/pwm/pwm-rz-mtu3.c base-commit: 9f258af06b6268be8e960f63c3f66e88bdbbbdb0 prerequisite-patch-id: 7d5c55db908971d16a58eb46b25d42dfb0f680ec prerequisite-patch-id: 6c15d33bb612750523d14af87a5cf9e6ff142540 prerequisite-patch-id: e5e4d86a0a012a59f585b84ce7ae0d3f047787dc prerequisite-patch-id: d62b4e1326f1518fd30eb98a37bfb4998573979a prerequisite-patch-id: 15bf63b610cab275387a2bbee7ab2a0a48414f75