From mboxrd@z Thu Jan 1 00:00:00 1970 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 0E999C6FA92 for ; Wed, 21 Sep 2022 15:00:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230472AbiIUPAI (ORCPT ); Wed, 21 Sep 2022 11:00:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230351AbiIUO7v (ORCPT ); Wed, 21 Sep 2022 10:59:51 -0400 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1462B9C23F; Wed, 21 Sep 2022 07:57:57 -0700 (PDT) X-IronPort-AV: E=Sophos;i="5.93,333,1654527600"; d="scan'208";a="135714721" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 21 Sep 2022 23:57:56 +0900 Received: from localhost.localdomain (unknown [10.226.92.58]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 45910425B09F; Wed, 21 Sep 2022 23:57:53 +0900 (JST) From: Biju Das To: Thierry Reding , Lee Jones , Philipp Zabel Cc: Biju Das , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , linux-pwm@vger.kernel.org, Geert Uytterhoeven , Chris Paterson , Biju Das , Prabhakar Mahadev Lad , linux-renesas-soc@vger.kernel.org Subject: [PATCH v7 2/2] pwm: Add support for RZ/G2L GPT Date: Wed, 21 Sep 2022 15:57:41 +0100 Message-Id: <20220921145741.901784-3-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220921145741.901784-1-biju.das.jz@bp.renesas.com> References: <20220921145741.901784-1-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 This patch adds basic pwm support for RZ/G2L GPT driver by creating separate logical channels for each IOs. Signed-off-by: Biju Das --- 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, when both channels used. 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 | 423 ++++++++++++++++++++++++++++++++++++ 3 files changed, 435 insertions(+) create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 60d13a949bc5..2723a3e9ff65 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -481,6 +481,17 @@ 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_RENESAS || 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_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 7bf1a29f02b8..cac39b18d1ee 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -44,6 +44,7 @@ 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_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o obj-$(CONFIG_PWM_SL28CPLD) += pwm-sl28cpld.o diff --git a/drivers/pwm/pwm-rzg2l-gpt.c b/drivers/pwm/pwm-rzg2l-gpt.c new file mode 100644 index 000000000000..c4e011f2a843 --- /dev/null +++ b/drivers/pwm/pwm-rzg2l-gpt.c @@ -0,0 +1,423 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L General PWM Timer (GPT) 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: + * - 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)) + +struct rzg2l_gpt_chip { + struct pwm_chip chip; + void __iomem *mmio; + struct reset_control *rstc; + struct clk *clk; + struct mutex lock; + u32 user_count; + u32 state_period; + unsigned long rate; + bool pwm_enabled_by_bootloader; +}; + +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) +{ + iowrite32(data, rzg2l_gpt->mmio + reg); +} + +static u32 rzg2l_gpt_read(struct rzg2l_gpt_chip *rzg2l_gpt, u32 reg) +{ + return ioread32(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_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 = (roundup_pow_of_two(prescaled_period_cycles + 1) + 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); + + mutex_lock(&rzg2l_gpt->lock); + rzg2l_gpt->user_count++; + 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); + + mutex_lock(&rzg2l_gpt->lock); + rzg2l_gpt->user_count--; + mutex_unlock(&rzg2l_gpt->lock); +} + +static int rzg2l_gpt_enable(struct rzg2l_gpt_chip *rzg2l_gpt) +{ + /* Start count */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR, 0, RZG2L_GTCR_CST); + + return 0; +} + +static void rzg2l_gpt_disable(struct rzg2l_gpt_chip *rzg2l_gpt) +{ + /* Stop count, Output low on GTIOCx pin when counting stops */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR, RZG2L_GTCR_CST, 0); +} + +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); + bool is_counter_running; + unsigned long pv, dc; + u64 period_cycles; + u64 duty_cycles; + u8 prescale; + + /* + * Refuse clk rates > 1 GHz to prevent overflowing the following + * calculation. + */ + if (rzg2l_gpt->rate > NSEC_PER_SEC) + return -EINVAL; + + /* + * 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 && rzg2l_gpt->user_count > 1) + return -EBUSY; + + /* + * 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 = state->period; + + period_cycles = mul_u64_u32_div(state->period, rzg2l_gpt->rate, NSEC_PER_SEC); + prescale = rzg2l_calculate_prescale(rzg2l_gpt, period_cycles); + + if (period_cycles >> (2 * prescale) <= U32_MAX) + pv = period_cycles >> (2 * prescale); + else + pv = U32_MAX; + + duty_cycles = mul_u64_u32_div(state->duty_cycle, rzg2l_gpt->rate, NSEC_PER_SEC); + + if (duty_cycles >> (2 * prescale) <= U32_MAX) + dc = duty_cycles >> (2 * prescale); + else + dc = U32_MAX; + + /* + * 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->user_count <= 1) + rzg2l_gpt_disable(rzg2l_gpt); + + is_counter_running = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR) & RZG2L_GTCR_CST; + if (!is_counter_running) + /* GPT set operating mode (saw-wave up-counting) */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR, RZG2L_GTCR_MD, + RZG2L_GTCR_MD_SAW_WAVE_PWM_MODE); + + /* Set count direction */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTUDDTYC, RZG2L_UP_COUNTING); + + if (!is_counter_running) + /* Select count clock */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR, RZG2L_GTCR_TPCS, + FIELD_PREP(RZG2L_GTCR_TPCS, prescale)); + + /* Set period */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTPR, pv); + + /* Set duty cycle */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTCCR(pwm->hwpwm), dc); + + if (!is_counter_running) { + /* Set initial value for counter */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTCNT, 0); + + /* Set no buffer operation */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTBER, 0); + } + + /* Enable pin output */ + if (pwm->hwpwm) + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTIOR, + RZG2L_GTIOR_GTIOB | RZG2L_GTIOR_OBE, + RZG2L_GTIOR_GTIOB_OUT_HI_END_TOGGLE_CMP_MATCH); + else + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTIOR, + RZG2L_GTIOR_GTIOA | RZG2L_GTIOR_OAE, + RZG2L_GTIOR_GTIOA_OUT_HI_END_TOGGLE_CMP_MATCH); + + return 0; +} + +static void 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); + u8 prescale; + u64 tmp; + u32 val; + + pm_runtime_get_sync(chip->dev); + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR); + state->enabled = val & RZG2L_GTCR_CST; + if (state->enabled) { + prescale = FIELD_GET(RZG2L_GTCR_TPCS, val); + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTPR); + tmp = NSEC_PER_SEC * (u64)val << (2 * prescale); + state->period = DIV_ROUND_UP_ULL(tmp, rzg2l_gpt->rate); + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCCR(pwm->hwpwm)); + tmp = NSEC_PER_SEC * (u64)val << (2 * prescale); + state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rzg2l_gpt->rate); + /* + * Ordering is important, when we set a period for the second + * channel, the pwm_request_from_chip() calling get_state() + * will have an invalid duty cycle value as the register is not + * initialized yet. + */ + if (state->duty_cycle > state->period) + state->duty_cycle = state->period; + } + + state->polarity = PWM_POLARITY_NORMAL; + pm_runtime_put(chip->dev); +} + +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); + int ret; + + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + pm_runtime_get_sync(chip->dev); + if (!state->enabled) { + if (rzg2l_gpt->pwm_enabled_by_bootloader) { + /* + * For PWM enabled by bootloader case, Release the clk + * framework resources and set the pwm_enabled_by_bootloader + * variable to false. After this clock is managed by PM. + */ + rzg2l_gpt->pwm_enabled_by_bootloader = false; + devm_clk_put(chip->dev, rzg2l_gpt->clk); + } + + rzg2l_gpt_disable(rzg2l_gpt); + ret = 0; + goto done; + } + + mutex_lock(&rzg2l_gpt->lock); + ret = rzg2l_gpt_config(chip, pwm, state); + mutex_unlock(&rzg2l_gpt->lock); + if (ret) + goto done; + + return rzg2l_gpt_enable(rzg2l_gpt); + +done: + pm_runtime_put(chip->dev); + + 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 const struct of_device_id rzg2l_gpt_of_table[] = { + { .compatible = "renesas,rzg2l-gpt", }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rzg2l_gpt_of_table); + +static void rzg2l_gpt_reset_assert_pm_disable(void *data) +{ + struct rzg2l_gpt_chip *rzg2l_gpt = data; + + pm_runtime_disable(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; + + 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_shared(&pdev->dev, NULL); + if (IS_ERR(rzg2l_gpt->rstc)) + return dev_err_probe(&pdev->dev, PTR_ERR(rzg2l_gpt->rstc), + "get reset failed\n"); + + ret = reset_control_deassert(rzg2l_gpt->rstc); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "cannot deassert reset control\n"); + + 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->clk = devm_clk_get_enabled(&pdev->dev, NULL); + if (IS_ERR(rzg2l_gpt->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(rzg2l_gpt->clk), + "cannot get clock\n"); + + rzg2l_gpt->rate = clk_get_rate(rzg2l_gpt->clk); + /* + * We need to keep the clock on, in case the bootloader has enabled the + * PWM and is running during probe(). A variable pwm_enabled_by_ + * bootloader is set to true in that case and during first + * pwm_disable(), it is set to false and release the clock resource. + * + * In case the pwm is not enabled by the bootloader, devm_clk_put + * disables the clk and holding a reference on the clk isn't needed + * because runtime-pm handles the needed enabling. + */ + if (rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR) & RZG2L_GTCR_CST) + rzg2l_gpt->pwm_enabled_by_bootloader = true; + else + devm_clk_put(&pdev->dev, rzg2l_gpt->clk); + + mutex_init(&rzg2l_gpt->lock); + + rzg2l_gpt->chip.dev = &pdev->dev; + rzg2l_gpt->chip.ops = &rzg2l_gpt_ops; + rzg2l_gpt->chip.npwm = 2; + + ret = devm_pwmchip_add(&pdev->dev, &rzg2l_gpt->chip); + if (ret) + dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n"); + + return ret; +} + +static struct platform_driver rzg2l_gpt_driver = { + .driver = { + .name = "pwm-rzg2l-gpt", + .of_match_table = of_match_ptr(rzg2l_gpt_of_table), + }, + .probe = rzg2l_gpt_probe, +}; +module_platform_driver(rzg2l_gpt_driver); + +MODULE_AUTHOR("Biju Das "); +MODULE_DESCRIPTION("Renesas RZ/G2L General PWM Timer (GPT) Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pwm-rzg2l-gpt"); -- 2.25.1