From patchwork Fri Jul 21 06:08:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Biju Das X-Patchwork-Id: 13321386 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D951C001DE for ; Fri, 21 Jul 2023 06:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230400AbjGUGJp (ORCPT ); Fri, 21 Jul 2023 02:09:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230246AbjGUGJN (ORCPT ); Fri, 21 Jul 2023 02:09:13 -0400 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 756EA1BC1; Thu, 20 Jul 2023 23:09:00 -0700 (PDT) X-IronPort-AV: E=Sophos;i="6.01,220,1684767600"; d="scan'208";a="173984330" Received: from unknown (HELO relmlir5.idc.renesas.com) ([10.200.68.151]) by relmlie6.idc.renesas.com with ESMTP; 21 Jul 2023 15:09:00 +0900 Received: from localhost.localdomain (unknown [10.226.92.55]) by relmlir5.idc.renesas.com (Postfix) with ESMTP id 7499040134E7; Fri, 21 Jul 2023 15:08:57 +0900 (JST) From: Biju Das To: Thierry Reding , Philipp Zabel Cc: Biju Das , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Geert Uytterhoeven , Magnus Damm , linux-pwm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Prabhakar Mahadev Lad Subject: [PATCH v15 3/4] pwm: Add support for RZ/G2L GPT Date: Fri, 21 Jul 2023 07:08:39 +0100 Message-Id: <20230721060840.8546-4-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230721060840.8546-1-biju.das.jz@bp.renesas.com> References: <20230721060840.8546-1-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org RZ/G2L General PWM Timer (GPT) composed of 8 channels with 32-bit timer (GPT32E). It supports the following functions * 32 bits × 8 channels * Up-counting or down-counting (saw waves) or up/down-counting (triangle waves) for each counter. * Clock sources independently selectable for each channel * Two I/O pins per channel * Two output compare/input capture registers per channel * For the two output compare/input capture registers of each channel, four registers are provided as buffer registers and are capable of operating as comparison registers when buffering is not in use. * In output compare operation, buffer switching can be at crests or troughs, enabling the generation of laterally asymmetric PWM waveforms. * Registers for setting up frame cycles in each channel (with capability for generating interrupts at overflow or underflow) * Generation of dead times in PWM operation * Synchronous starting, stopping and clearing counters for arbitrary channels * Starting, stopping, clearing and up/down counters in response to input level comparison * Starting, clearing, stopping and up/down counters in response to a maximum of four external triggers * Output pin disable function by dead time error and detected short-circuits between output pins * A/D converter start triggers can be generated (GPT32E0 to GPT32E3) * Enables the noise filter for input capture and external trigger operation Add basic pwm support for RZ/G2L GPT driver by creating separate logical channels for each IOs. Signed-off-by: Biju Das --- v14->v15: * Added enable_count and ch_en_bits variables to struct rzg2l_gpt_chip based on feedback for pwm_mtu3 driver. * Updated copyright header and commit description by replacing "This patch adds"-> "Add" * Replaced macro RZG2L_GET_CH_INDEX->RZG2L_GET_CH and replaced ch_index->ch throughout * rzg2l_gpt_{enable,disable}() enables/disables PWM based on the enable_count. * Replaced pm_runtime_get_sync->pm_runtime_resume_and_get and propogated the error in rzg2l_gpt_get_state() and rzg2l_gpt_config() * Reduced variable scope in rzg2l_gpt_get_state() by moving most of variables inside the if statement. * Updated rzg2l_gpt_get_state() by moving duty > period check inside the top if block. * Added helper functions rzg2l_gpt_calculate_pv_or_dc()to simplify config. Also Improved the logic in rzg2l_gpt_calculate_pv_or_dc() by using min(period_or_duty_cycle >> (2 * prescale), (u64)U32_MAX); * Updated rzg2l_gpt_get_state() by moving duty > period check inside the top if block. * Simplified rzg2l_gpt_config() for updating registers * Dropped pm_runtime_get_sync() and used bitmap variable "ch_en_bits" to make balanced PM usage count in rzg2l_gpt_reset_assert_pm_disable() For case were unbind is called before apply where pwm is enabled by bootloader. * Added error check for clk_rate_exclusive_get() and clk_get_rate() in probe(). * Dropped prescale from struct rzg2l_gpt_chip. * Replaced of_match_ptr(rzg2l_gpt_of_table)->rzg2l_gpt_of_table in struct rzg2l_gpt_driver v13->v14: * Removed parenthesis for RZG2L_MAX_HW_CHANNELS and RZG2L_CHANNELS_PER_IO * Removed duty_cycle variable from struct rzg2l_gpt_chip and added comment for cache for prescale variable. * Fixed a bug in rzg2l_gpt_cntr_need_stop(). * Reordered rzg2l_gpt_config() just above apply() * Replaced pwm_is_enabled()->pwm->state.enabled in config * Replaced pm_runtime_resume_and_get with unconditional pm_runtime_get_sync() in config(). * Restored duty_cycle > period check in rzg2l_gpt_get_state(). * 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_get() * Simplified rzg2l_gpt_probe() by removing bitmap variables. * Added pm_runtime_idle() to suspend the device during probe. * Moved overflow condition check from config->probe(). * Simplified rzg2l_gpt_reset_assert_pm_disable(). v12->v13: * Replaced Kconfig dependency from ARCH_RENESAS->ARCH_RZG2L * Sorted #include alphabetically * Added a comment for mutex_lock to fix check patch warning * Replaced data type of duty_cycle from unsigned int->u32 as the maximum value stored is U32_MAX. * Improved rzg2l_gpt_config() by removing unwanted duty_cycle related code. * Improved rzg2l_gpt_get_state() by setting "val = rzg2l_gpt->duty_cycle[pwm->hwpwm];", and factor "tmp = NSEC_PER_SEC * (u64)val;" out of the if-statement. * Started using DEFINE_RUNTIME_DEV_PM_OPS(), and dropped __maybe_unused from the callbacks. v11->v12: * Added return code for get_state() * Cache duty cycle/prescale as 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. * Updated rzg2l_gpt_enable to enable the clocks. * Updated rzg2l_gpt_disable to disable the clocks. * Updated rzg2l_gpt_config() to cache duty cucle/prescale value * Updated rzg2l_gpt_get_state to use cached value of duty cycle/prescale,If the PWM is disabled. * Simplified rzg2l_gpt_apply() * Added comments in rzg2l_gpt_reset_assert_pm_disable() v10->v11: * Used bitmap_zero for initializing bitmap varable. * Fixed clock imbalance during remove for the case bootloader turning on PWM and module unload is called just after the boot. * Fixed over flow condition in get_state() for a prescale value of 2 & more. * Improved rzg2l_gpt_cntr_need_stop() based on prescale as it is the only runtime variable. * Added array for Cache variables state_period and prescale * Probe caches the prescale value set by the bootloader. * Updated rzg2l_gpt_config() to make use of array variables. v9->v10: * Updated the error handling in probe(), clk_disable_unprepare called on the error path. * Removed ch_en array and started using bitmask instead. v8->v9: * deassert after devm_clk_get() to avoid reset stays deasserted,in case clk_get() fails. * Removed ch_offs from struct rzg2l_gpt_chip and use macro instead. * Updated error handling in probe() v7->v8: * Modelled as single PWM device handling multiple channels * Replaced shared reset->devm_reset_control_get_exclusive() * Replaced iowrite32->writel and ioread32->readl * Updated prescale calculation * Added PM runtime callbacks * Updated PM handling and removed "pwm_enabled_by_bootloader" variable * Introduced rzg2l_gpt_is_ch_enabled for checking enable status on both IO's * Moved enable/disable output pins from config->enable/disable. * Added rzg2l_gpt_cntr_need_stop() for caching prescalar/mode values. v6->v7: * Added the comment for cacheing rzg2l_gpt->state_period. * Fixed boundary values for pv and dc. * Added comment for modifying mode, prescaler, timer counter and buffer enable registers. * Fixed buffer overflow in get_state() * Removed unnecessary assignment of state->period value in get_state(). * Fixed state->duty_cycle value in get_state(). * Added a limitation for disabling the channels. v5->v6: * Updated macros RZG2L_GTIOR_GTIOB_OUT_HI_END_TOGGLE_CMP_MATCH and RZG2L_GTIOR_GTIOB_OUT_LO_END_TOGGLE_CMP_MATCH with computation involving FIELD_PREP macro. * Removed struct rzg2l_gpt_phase and started using RZG2L_GTCCR macro for duty_offset. * replaced misnomer real_period->state_period. * Added handling for values >= (1024 << 32) for both period and duty cycle. * Added comments for pwm {en,dis}abled by bootloader during probe. v4->v5: * Added Hardware manual details * Replaced the comment GTCNT->Counter * Removed the macros RZG2L_GPT_IO_PER_CHANNEL and chip.npwm directly used in probe. * Removed the unsed macro RZG2L_GTPR_MAX_VALUE * Added driver prefix for the type name and the variable. * Initialization of per_channel data moved from request->probe. * Updated clr parameter for rzg2l_gpt_modify for Start count. * Started using mutex and usage_count for handling shared period and prescalar for the 2 channels. * Updated the comment cycle->period. * Removed clk_disable from rzg2l_gpt_reset_assert_pm_disable() * Replaced pc->rzg2l_gpt. * Updated prescale calculation. * Moved pm_runtime_{get_sync,put} from {request,free}->{enable,disable} * Removed platform_set_drvdata as it is unused * Removed the variable pwm_enabled_by_bootloader * Added dev_err_probe in various error paths in probe. * Added an error message, if devm_pwmchip_add() fails. v3->v4: * Changed the local variable type i from u16->u8 and prescaled_period_ cycles from u64->u32 in calculate_prescale(). * Replaced mul_u64_u64_div_u64()->mul_u64_u32_div() * Dropped the comma after the sentinel. * Add a variable to track pwm enabled by bootloader and added comments in probe(). * Removed unnecessary rzg2l_gpt_reset_assert_pm_disable() from probe. * Replaced devm_clk_get()->devm_clk_get_prepared() * Removed devm_clk_get_optional_enabled() v2->v3: * Updated limitation section * Added prefix "RZG2L_" for all macros * Modified prescale calculation * Removed pwm_set_chip_data * Updated comment related to modifying Mode and Prescaler * Updated setting of prescale value in rzg2l_gpt_config() * Removed else branch from rzg2l_gpt_get_state() * removed the err label from rzg2l_gpt_apply() * Added devm_clk_get_optional_enabled() to retain clk on status, in case bootloader turns on the clk of pwm. * Replaced devm_reset_control_get_exclusive->devm_reset_control_get_shared as single reset shared between 8 channels. v1->v2: * Added Limitations section * dropped "_MASK" from the define names. * used named initializer for struct phase * Added gpt_pwm_device into a flexible array member in rzg2l_gpt_chip * Revised the logic for prescale * Added .get_state callback * Improved error handling in rzg2l_gpt_apply * Removed .remove callback * Tested driver with PWM_DEBUG enabled RFC->V1: * Updated macros * replaced rzg2l_gpt_write_mask()->rzg2l_gpt_modify() * Added rzg2l_gpt_read() --- drivers/pwm/Kconfig | 11 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-rzg2l-gpt.c | 557 ++++++++++++++++++++++++++++++++++++ 3 files changed, 569 insertions(+) create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 6210babb0741..031ceaf09de7 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -503,6 +503,17 @@ config PWM_ROCKCHIP Generic PWM framework driver for the PWM controller found on Rockchip SoCs. +config PWM_RZG2L_GPT + tristate "Renesas RZ/G2L General PWM Timer support" + depends on ARCH_RZG2L || COMPILE_TEST + depends on HAS_IOMEM + help + This driver exposes the General 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-rzg2l-gpt. + config PWM_RZ_MTU3 tristate "Renesas RZ/G2L MTU3a PWM Timer support" depends on RZ_MTU3 || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index c822389c2a24..d579825f11bf 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -46,6 +46,7 @@ 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-$(CONFIG_PWM_RZG2L_GPT) += pwm-rzg2l-gpt.o obj-$(CONFIG_PWM_RZ_MTU3) += pwm-rz-mtu3.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o diff --git a/drivers/pwm/pwm-rzg2l-gpt.c b/drivers/pwm/pwm-rzg2l-gpt.c new file mode 100644 index 000000000000..38243c1a63ab --- /dev/null +++ b/drivers/pwm/pwm-rzg2l-gpt.c @@ -0,0 +1,557 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L General PWM Timer (GPT) 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: + * - Counter must be stopped before modifying Mode and Prescaler. + * - When PWM is disabled, the output is driven to inactive. + * - While the hardware supports both polarities, the driver (for now) + * only handles normal polarity. + * - When both channels are used, disabling the channel on one stops the + * other. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define RZG2L_GTCR 0x2c +#define RZG2L_GTUDDTYC 0x30 +#define RZG2L_GTIOR 0x34 +#define RZG2L_GTBER 0x40 +#define RZG2L_GTCNT 0x48 +#define RZG2L_GTCCRA 0x4c +#define RZG2L_GTCCRB 0x50 +#define RZG2L_GTPR 0x64 + +#define RZG2L_GTCR_CST BIT(0) +#define RZG2L_GTCR_MD GENMASK(18, 16) +#define RZG2L_GTCR_TPCS GENMASK(26, 24) + +#define RZG2L_GTCR_MD_SAW_WAVE_PWM_MODE FIELD_PREP(RZG2L_GTCR_MD, 0) + +#define RZG2L_GTUDDTYC_UP BIT(0) +#define RZG2L_GTUDDTYC_UDF BIT(1) +#define RZG2L_UP_COUNTING (RZG2L_GTUDDTYC_UP | RZG2L_GTUDDTYC_UDF) + +#define RZG2L_GTIOR_GTIOA GENMASK(4, 0) +#define RZG2L_GTIOR_GTIOB GENMASK(20, 16) +#define RZG2L_GTIOR_OAE BIT(8) +#define RZG2L_GTIOR_OBE BIT(24) + +#define RZG2L_INIT_OUT_LO_OUT_LO_END_TOGGLE 0x07 +#define RZG2L_INIT_OUT_HI_OUT_HI_END_TOGGLE 0x1b + +#define RZG2L_GTIOR_GTIOA_OUT_HI_END_TOGGLE_CMP_MATCH \ + (RZG2L_INIT_OUT_HI_OUT_HI_END_TOGGLE | RZG2L_GTIOR_OAE) +#define RZG2L_GTIOR_GTIOA_OUT_LO_END_TOGGLE_CMP_MATCH \ + (RZG2L_INIT_OUT_LO_OUT_LO_END_TOGGLE | RZG2L_GTIOR_OAE) +#define RZG2L_GTIOR_GTIOB_OUT_HI_END_TOGGLE_CMP_MATCH \ + (FIELD_PREP(RZG2L_GTIOR_GTIOB, RZG2L_INIT_OUT_HI_OUT_HI_END_TOGGLE) | RZG2L_GTIOR_OBE) +#define RZG2L_GTIOR_GTIOB_OUT_LO_END_TOGGLE_CMP_MATCH \ + (FIELD_PREP(RZG2L_GTIOR_GTIOB, RZG2L_INIT_OUT_LO_OUT_LO_END_TOGGLE) | RZG2L_GTIOR_OBE) + +#define RZG2L_GTCCR(i) (0x4c + 4 * (i)) + +#define RZG2L_MAX_HW_CHANNELS 8 +#define RZG2L_CHANNELS_PER_IO 2 +#define RZG2L_MAX_PWM_CHANNELS (RZG2L_MAX_HW_CHANNELS * RZG2L_CHANNELS_PER_IO) + +#define RZG2L_IS_IOB(a) ((a) & 0x1) +#define RZG2L_GET_CH(a) ((a) / 2) + +#define RZG2L_GET_CH_OFFS(i) (0x100 * (i)) + +struct rzg2l_gpt_chip { + struct pwm_chip chip; + void __iomem *mmio; + struct reset_control *rstc; + struct clk *clk; + struct mutex lock; /* lock to protect shared channel resources */ + unsigned long rate; + u32 state_period[RZG2L_MAX_HW_CHANNELS]; + u32 user_count[RZG2L_MAX_HW_CHANNELS]; + u32 enable_count[RZG2L_MAX_HW_CHANNELS]; + DECLARE_BITMAP(ch_en_bits, RZG2L_MAX_PWM_CHANNELS); +}; + +static inline struct rzg2l_gpt_chip *to_rzg2l_gpt_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct rzg2l_gpt_chip, chip); +} + +static void rzg2l_gpt_write(struct rzg2l_gpt_chip *rzg2l_gpt, u32 reg, u32 data) +{ + writel(data, rzg2l_gpt->mmio + reg); +} + +static u32 rzg2l_gpt_read(struct rzg2l_gpt_chip *rzg2l_gpt, u32 reg) +{ + return readl(rzg2l_gpt->mmio + reg); +} + +static void rzg2l_gpt_modify(struct rzg2l_gpt_chip *rzg2l_gpt, u32 reg, u32 clr, + u32 set) +{ + rzg2l_gpt_write(rzg2l_gpt, reg, + (rzg2l_gpt_read(rzg2l_gpt, reg) & ~clr) | set); +} + +static u8 rzg2l_gpt_calculate_prescale(struct rzg2l_gpt_chip *rzg2l_gpt, + u64 period_cycles) +{ + u32 prescaled_period_cycles; + u8 prescale; + + prescaled_period_cycles = period_cycles >> 32; + if (prescaled_period_cycles >= 256) + prescale = 5; + else + prescale = (fls(prescaled_period_cycles) + 1) / 2; + + return prescale; +} + +static int rzg2l_gpt_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = to_rzg2l_gpt_chip(chip); + u32 ch = RZG2L_GET_CH(pwm->hwpwm); + + mutex_lock(&rzg2l_gpt->lock); + rzg2l_gpt->user_count[ch]++; + mutex_unlock(&rzg2l_gpt->lock); + + return 0; +} + +static void rzg2l_gpt_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = to_rzg2l_gpt_chip(chip); + u32 ch = RZG2L_GET_CH(pwm->hwpwm); + + mutex_lock(&rzg2l_gpt->lock); + rzg2l_gpt->user_count[ch]--; + mutex_unlock(&rzg2l_gpt->lock); +} + +static bool rzg2l_gpt_is_ch_enabled(struct rzg2l_gpt_chip *rzg2l_gpt, u8 hwpwm) +{ + u8 ch = RZG2L_GET_CH(hwpwm); + u32 offs = RZG2L_GET_CH_OFFS(ch); + bool is_counter_running, is_output_en; + u32 val; + + val = rzg2l_gpt_read(rzg2l_gpt, offs + RZG2L_GTCR); + is_counter_running = val & RZG2L_GTCR_CST; + + val = rzg2l_gpt_read(rzg2l_gpt, offs + RZG2L_GTIOR); + if (RZG2L_IS_IOB(hwpwm)) + is_output_en = val & RZG2L_GTIOR_OBE; + else + is_output_en = val & RZG2L_GTIOR_OAE; + + return (is_counter_running && is_output_en); +} + +static int rzg2l_gpt_enable(struct rzg2l_gpt_chip *rzg2l_gpt, + struct pwm_device *pwm) +{ + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + u32 offs = RZG2L_GET_CH_OFFS(ch); + int rc; + + rc = pm_runtime_resume_and_get(rzg2l_gpt->chip.dev); + if (rc) + return rc; + + /* Enable pin output */ + if (RZG2L_IS_IOB(pwm->hwpwm)) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTIOR, + RZG2L_GTIOR_GTIOB | RZG2L_GTIOR_OBE, + RZG2L_GTIOR_GTIOB_OUT_HI_END_TOGGLE_CMP_MATCH); + else + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTIOR, + RZG2L_GTIOR_GTIOA | RZG2L_GTIOR_OAE, + RZG2L_GTIOR_GTIOA_OUT_HI_END_TOGGLE_CMP_MATCH); + + mutex_lock(&rzg2l_gpt->lock); + if (!rzg2l_gpt->enable_count[ch]) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, 0, RZG2L_GTCR_CST); + + rzg2l_gpt->enable_count[ch]++; + mutex_unlock(&rzg2l_gpt->lock); + + return 0; +} + +static void rzg2l_gpt_disable(struct rzg2l_gpt_chip *rzg2l_gpt, + struct pwm_device *pwm) +{ + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + u32 offs = RZG2L_GET_CH_OFFS(ch); + + /* Disable pin output */ + if (RZG2L_IS_IOB(pwm->hwpwm)) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTIOR, RZG2L_GTIOR_OBE, 0); + else + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTIOR, RZG2L_GTIOR_OAE, 0); + + /* Stop count, Output low on GTIOCx pin when counting stops */ + mutex_lock(&rzg2l_gpt->lock); + rzg2l_gpt->enable_count[ch]--; + if (!rzg2l_gpt->enable_count[ch]) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, RZG2L_GTCR_CST, 0); + + mutex_unlock(&rzg2l_gpt->lock); + + /* + * Probe() set these bits, if pwm is enabled by bootloader. In such + * case, clearing the bits will avoid errors during unbind. + */ + if (test_bit(pwm->hwpwm, rzg2l_gpt->ch_en_bits)) + clear_bit(pwm->hwpwm, rzg2l_gpt->ch_en_bits); + + pm_runtime_put_sync(rzg2l_gpt->chip.dev); +} + +static int rzg2l_gpt_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = to_rzg2l_gpt_chip(chip); + int rc; + + rc = pm_runtime_resume_and_get(chip->dev); + if (rc) + return rc; + + state->enabled = rzg2l_gpt_is_ch_enabled(rzg2l_gpt, pwm->hwpwm); + if (state->enabled) { + u32 ch = RZG2L_GET_CH(pwm->hwpwm); + u32 offs = RZG2L_GET_CH_OFFS(ch); + u8 prescale; + u64 tmp; + u32 val; + + val = rzg2l_gpt_read(rzg2l_gpt, offs + RZG2L_GTCR); + prescale = FIELD_GET(RZG2L_GTCR_TPCS, val); + + val = rzg2l_gpt_read(rzg2l_gpt, offs + RZG2L_GTPR); + tmp = NSEC_PER_SEC * (u64)val; + state->period = DIV_ROUND_UP_ULL(tmp, rzg2l_gpt->rate) << (2 * prescale); + val = rzg2l_gpt_read(rzg2l_gpt, + offs + RZG2L_GTCCR(RZG2L_IS_IOB(pwm->hwpwm))); + + tmp = NSEC_PER_SEC * (u64)val; + state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rzg2l_gpt->rate) << (2 * prescale); + + if (state->duty_cycle > state->period) + state->duty_cycle = state->period; + } + + state->polarity = PWM_POLARITY_NORMAL; + pm_runtime_put(chip->dev); + + return 0; +} + +static u32 rzg2l_gpt_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 prescale) +{ + return min(period_or_duty_cycle >> (2 * prescale), (u64)U32_MAX); +} + +static int rzg2l_gpt_config(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = to_rzg2l_gpt_chip(chip); + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + u32 offs = RZG2L_GET_CH_OFFS(ch); + unsigned long pv, dc; + u64 period_cycles; + u64 duty_cycles; + u8 prescale; + + /* + * GPT counter is shared by multiple channels, so prescale and period + * can NOT be modified when there are multiple channels in use with + * different settings. + */ + if (state->period != rzg2l_gpt->state_period[ch] && rzg2l_gpt->user_count[ch] > 1) + return -EBUSY; + + period_cycles = mul_u64_u32_div(state->period, rzg2l_gpt->rate, NSEC_PER_SEC); + prescale = rzg2l_gpt_calculate_prescale(rzg2l_gpt, period_cycles); + + pv = rzg2l_gpt_calculate_pv_or_dc(period_cycles, prescale); + + duty_cycles = mul_u64_u32_div(state->duty_cycle, rzg2l_gpt->rate, NSEC_PER_SEC); + dc = rzg2l_gpt_calculate_pv_or_dc(duty_cycles, prescale); + + /* + * GPT counter is shared by multiple channels, we cache the period value + * from the first enabled channel and use the same value for both + * channels. + */ + rzg2l_gpt->state_period[ch] = state->period; + + /* + * 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; + } + + /* + * Counter must be stopped before modifying mode, prescaler, timer + * counter and buffer enable registers. These registers are shared + * between both channels. So allow updating these registers only for the + * first enabled channel. + */ + if (rzg2l_gpt->enable_count[ch] > 1) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, RZG2L_GTCR_CST, 0); + + /* GPT set operating mode (saw-wave up-counting) */ + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, RZG2L_GTCR_MD, + RZG2L_GTCR_MD_SAW_WAVE_PWM_MODE); + + /* Set count direction */ + rzg2l_gpt_write(rzg2l_gpt, offs + RZG2L_GTUDDTYC, RZG2L_UP_COUNTING); + /* Select count clock */ + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, RZG2L_GTCR_TPCS, + FIELD_PREP(RZG2L_GTCR_TPCS, prescale)); + + /* Set period */ + rzg2l_gpt_write(rzg2l_gpt, offs + RZG2L_GTPR, pv); + + /* Set duty cycle */ + rzg2l_gpt_write(rzg2l_gpt, offs + RZG2L_GTCCR(RZG2L_IS_IOB(pwm->hwpwm)), + dc); + + /* Set initial value for counter */ + rzg2l_gpt_write(rzg2l_gpt, offs + RZG2L_GTCNT, 0); + + /* Set no buffer operation */ + rzg2l_gpt_write(rzg2l_gpt, offs + RZG2L_GTBER, 0); + + /* Restart the counter after updating the registers */ + if (rzg2l_gpt->enable_count[ch] > 1) + rzg2l_gpt_modify(rzg2l_gpt, offs + RZG2L_GTCR, + RZG2L_GTCR_CST, RZG2L_GTCR_CST); + + /* 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 rzg2l_gpt_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = to_rzg2l_gpt_chip(chip); + bool enabled = pwm->state.enabled; + int ret; + + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + if (!state->enabled) { + if (enabled) + rzg2l_gpt_disable(rzg2l_gpt, pwm); + + return 0; + } + + mutex_lock(&rzg2l_gpt->lock); + ret = rzg2l_gpt_config(chip, pwm, state); + mutex_unlock(&rzg2l_gpt->lock); + if (ret) + return ret; + + if (!enabled) + ret = rzg2l_gpt_enable(rzg2l_gpt, pwm); + + return ret; +} + +static const struct pwm_ops rzg2l_gpt_ops = { + .request = rzg2l_gpt_request, + .free = rzg2l_gpt_free, + .get_state = rzg2l_gpt_get_state, + .apply = rzg2l_gpt_apply, + .owner = THIS_MODULE, +}; + +static int rzg2l_gpt_pm_runtime_suspend(struct device *dev) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = dev_get_drvdata(dev); + + clk_disable_unprepare(rzg2l_gpt->clk); + + return 0; +} + +static int rzg2l_gpt_pm_runtime_resume(struct device *dev) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = dev_get_drvdata(dev); + + return clk_prepare_enable(rzg2l_gpt->clk); +} + +static DEFINE_RUNTIME_DEV_PM_OPS(rzg2l_gpt_pm_ops, + rzg2l_gpt_pm_runtime_suspend, + rzg2l_gpt_pm_runtime_resume, NULL); + +static void rzg2l_gpt_reset_assert_pm_disable(void *data) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = data; + u32 i; + + clk_rate_exclusive_put(rzg2l_gpt->clk); + /* + * The below check is for making balanced PM usage count + * eg: boot loader is turning on PWM and probe increments the PM usage + * count. Before apply, if there is unbind/remove callback we need to + * decrement the PM usage count. + */ + for (i = 0; i < RZG2L_MAX_PWM_CHANNELS; i++) { + if (test_bit(i, rzg2l_gpt->ch_en_bits)) + pm_runtime_put(rzg2l_gpt->chip.dev); + } + + pm_runtime_disable(rzg2l_gpt->chip.dev); + pm_runtime_set_suspended(rzg2l_gpt->chip.dev); + reset_control_assert(rzg2l_gpt->rstc); +} + +static int rzg2l_gpt_probe(struct platform_device *pdev) +{ + struct rzg2l_gpt_chip *rzg2l_gpt; + int ret; + u32 i; + + rzg2l_gpt = devm_kzalloc(&pdev->dev, sizeof(*rzg2l_gpt), GFP_KERNEL); + if (!rzg2l_gpt) + return -ENOMEM; + + rzg2l_gpt->mmio = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rzg2l_gpt->mmio)) + return PTR_ERR(rzg2l_gpt->mmio); + + rzg2l_gpt->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (IS_ERR(rzg2l_gpt->rstc)) + return dev_err_probe(&pdev->dev, PTR_ERR(rzg2l_gpt->rstc), + "get reset failed\n"); + + rzg2l_gpt->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(rzg2l_gpt->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(rzg2l_gpt->clk), + "cannot get clock\n"); + + ret = reset_control_deassert(rzg2l_gpt->rstc); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "cannot deassert reset control\n"); + + ret = clk_prepare_enable(rzg2l_gpt->clk); + if (ret) + goto err_reset; + + ret = clk_rate_exclusive_get(rzg2l_gpt->clk); + if (ret) + goto err_clk_disable; + + rzg2l_gpt->rate = clk_get_rate(rzg2l_gpt->clk); + if (!rzg2l_gpt->rate) { + dev_err_probe(&pdev->dev, -EINVAL, "gpt clk rate is 0"); + goto err_clk_rate_put; + } + + /* + * Refuse clk rates > 1 GHz to prevent overflow later for computing + * period and duty cycle. + */ + if (rzg2l_gpt->rate > NSEC_PER_SEC) { + ret = -EINVAL; + goto err_clk_rate_put; + } + + /* + * We need to keep the clock on, in case the bootloader has enabled the + * PWM and is running during probe(). + */ + for (i = 0; i < RZG2L_MAX_PWM_CHANNELS; i++) { + if (rzg2l_gpt_is_ch_enabled(rzg2l_gpt, i)) { + set_bit(i, rzg2l_gpt->ch_en_bits); + pm_runtime_get_sync(&pdev->dev); + } + } + + mutex_init(&rzg2l_gpt->lock); + platform_set_drvdata(pdev, rzg2l_gpt); + rzg2l_gpt->chip.dev = &pdev->dev; + + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + ret = devm_add_action_or_reset(&pdev->dev, + rzg2l_gpt_reset_assert_pm_disable, + rzg2l_gpt); + if (ret < 0) + return ret; + + rzg2l_gpt->chip.ops = &rzg2l_gpt_ops; + rzg2l_gpt->chip.npwm = RZG2L_MAX_PWM_CHANNELS; + ret = devm_pwmchip_add(&pdev->dev, &rzg2l_gpt->chip); + if (ret) + return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n"); + + pm_runtime_idle(&pdev->dev); + + return 0; + +err_clk_rate_put: + clk_rate_exclusive_put(rzg2l_gpt->clk); +err_clk_disable: + clk_disable_unprepare(rzg2l_gpt->clk); +err_reset: + reset_control_assert(rzg2l_gpt->rstc); + return ret; +} + +static const struct of_device_id rzg2l_gpt_of_table[] = { + { .compatible = "renesas,rzg2l-gpt", }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rzg2l_gpt_of_table); + +static struct platform_driver rzg2l_gpt_driver = { + .driver = { + .name = "pwm-rzg2l-gpt", + .pm = pm_ptr(&rzg2l_gpt_pm_ops), + .of_match_table = rzg2l_gpt_of_table, + }, + .probe = rzg2l_gpt_probe, +}; +module_platform_driver(rzg2l_gpt_driver); + +MODULE_AUTHOR("Biju Das "); +MODULE_ALIAS("platform:pwm-rzg2l-gpt"); +MODULE_DESCRIPTION("Renesas RZ/G2L General PWM Timer (GPT) Driver"); +MODULE_LICENSE("GPL");