From patchwork Fri Oct 18 13:00:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Biju Das X-Patchwork-Id: 13841733 X-Patchwork-Delegate: geert@linux-m68k.org Received: from relmlie5.idc.renesas.com (relmlor1.renesas.com [210.160.252.171]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EB2EC801; Fri, 18 Oct 2024 13:01:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.160.252.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729256476; cv=none; b=Y2csxBnd4ow9cv7PDb9mZ5GQ7ilPDlSvAmHFG4Rn5MTVmNt8FyapYRUREChvmUbzv2ruxFhBfu/DMQ+loILzImHphALNUr0GetYLTppO81uc1t+y4gFjFykI0YxF58or/1YIND42ja4/Gxlx7XqiOP9KM/tIDppQoHOwyw4qxR4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729256476; c=relaxed/simple; bh=J96nGO1YVzn05SYle8IO5t/1zqJXyIvnePQtCcLq2Xs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=O6Z2INeBgFI+kzf+K5wgnL4A5BA4gHBkUTNkZNVfMn9Ruqeccc0l7UaN1zmqmZxGtDJHMHjhbbA4ElkFt5uRGaoVqwlqDCS0K5j9svpTRbcJrK33wlGJ0wUrQWp/Dme/RHFdtSmQtr+4u3Y9WAcF3cY3FmEMS8zBFzr8tPgBjZA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=bp.renesas.com; spf=pass smtp.mailfrom=bp.renesas.com; arc=none smtp.client-ip=210.160.252.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=bp.renesas.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bp.renesas.com X-IronPort-AV: E=Sophos;i="6.11,213,1725289200"; d="scan'208";a="222337148" Received: from unknown (HELO relmlir5.idc.renesas.com) ([10.200.68.151]) by relmlie5.idc.renesas.com with ESMTP; 18 Oct 2024 22:01:12 +0900 Received: from localhost.localdomain (unknown [10.226.93.163]) by relmlir5.idc.renesas.com (Postfix) with ESMTP id 56EFF4007D02; Fri, 18 Oct 2024 22:01:05 +0900 (JST) From: Biju Das To: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Philipp Zabel Cc: Biju Das , Geert Uytterhoeven , Magnus Damm , linux-pwm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Prabhakar Mahadev Lad , Biju Das Subject: [PATCH v22 3/4] pwm: Add support for RZ/G2L GPT Date: Fri, 18 Oct 2024 14:00:44 +0100 Message-ID: <20241018130049.138775-4-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241018130049.138775-1-biju.das.jz@bp.renesas.com> References: <20241018130049.138775-1-biju.das.jz@bp.renesas.com> Precedence: bulk X-Mailing-List: linux-renesas-soc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 RZ/G2L General PWM Timer (GPT) composed of 8 channels with 32-bit timer (GPT32E). It supports the following functions * 32 bits x 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 --- v21->v22: * Started using guard(mutex)calls. * Replaced round up->down operation in rzg2l_gpt_calculate_pv_or_dc() as it converts a nanosecond value to a register value. * Replaced devm_clk_get->devm_clk_get_enabled() to make clock on during the lifetime of driver and get rid of bootloader_enabled_channels variable. Also dropped rzg2l_gpt_rpm_put(), pm_runtime.h header and pm runtime calls, that simplified the probe() and other functions. * Replaced return type of the rzg2l_gpt_enable() as void as it is not returning any error. * Dropped lock from enable() and disable() as caller is holding the lock. this way we won't release the lock just to allow a called function to retake it. v20->v21: * Added documentation about the relation between channels and outputs and subchannels. * Dropped using the local variable offs for calculating channel regs and instead start using macros. * Replaced u8->bool for the bootloader_enabled_channels variable in struct rzg2l_gpt_chip * Replaced duty_cycles->duty_ticks and period_cycles->period_ticks as it represent hw ticks. * Introduced RZG2L_MAX_TICKS macro for max hw ticks and dropped the variable max_val from struct rzg2l_gpt_chip. * Updated comment related to 64-bit overflow calculation in calculate_period_or_duty(). * Simplified handling of bootloader_enabled_channels[pwm->hwpwm] == true in a single place in rzg2l_gpt_apply() * For config error case, don't call pm_runtime_put_sync() and with enable()->acquire pm_runtime reference and disable()-->release the pm_runtime reference * Split the cleanups into two. One for reset_control_deassert() earlier in .probe() and dropped rstc variable from struct rzg2l_gpt_chip. * Added warn_once() message in probe() for bootloader setting wrong prescale values. v19->v20: * Added locks for rmw operations in rzg2l_gpt_{en,dis}able(). * Dropped decremeng enable_count based ch_en_bits in rzg2l_gpt_disable(). * Added a comment in calculate_period_or_duty() related to overflow. * Replaced ch_en_bits->bootloader_enabled_channels and used this variable in probe(), apply() and remove() for simplification * Replaced pm_runtime_enable()->devm_pm_runtime_enable() v18->v19: * Replaced RZG2L_UP_COUNTING->RZG2L_GTUDDTYC_UP_COUNTING macro. * Aligned RZG2L_GET_CH and RZG2L_GET_CH_OFFS macro * Dropped chip and clk from struct rzg2l_gpt_chip as started using devm_pwmchip_alloc() and devm_clk_rate_exclusive_get() to replace it. * Replaced rate->rate_khz in struct rzg2l_gpt_chip and added a check in probe() to make sure rate is multiple of 1000. * Replaced container_of->pwmchip_get_drvdata() to get device data. * Added a check in rzg2l_gpt_disable() not to decrement enable_count if ch_en_bits is set by the probe. * Dropped rzg2l_gpt_mul_u64_u64_div_u64() * Simplified calculate_period_or_duty() using rate_khz * Simplified rzg2l_gpt_config() using min macro for calculating period and duty_cycle. * Added checks in rzg2l_gpt_config() to prevent second channel setting shared register. * Updated error handling rzg2l_gpt_apply() * Added local variable dev for &pdev->dev in probe() * Added local varibles rate, chip and clk in probe() * Dropped err_clk_rate_put label as started using devm_clk_rate_exclusive_get() * Replaced rzg2l_gpt->chip as data for devm_add_action_or_reset(). * Added error message for rate > 1GHz in probe. v17->v18: * Updated copyright from 2023->2024. * Added units.h for KILO macro. * Replaced RZG2L_GTCCR{A,B}->RZG2L_GTCCR(i) * Introduced macros RZG2L_GTIOR_{GTIOx,OxE} to handle subchannels. * Replaced RZG2L_IS_IOB()->rzg2l_gpt_subchannel() * Replaced the cache period->period_cycles. * Updated rzg2l_gpt_is_ch_enabled() to return early if counter is not running. * Updated calculate_period_or_duty() for avoiding overflows. * Updated rzg2l_gpt_calculate_pv_or_dc() with simplified calculation for DIV64_U64_ROUND_UP() and dropped the cast for U32_MAX in min_t. * Replaced mul_u64_u32_div->rzg2l_gpt_mul_u64_u64_div_u64() helper. * Dropped pm pointer from struct rzg2l_gpt_driver() and simplified clk handling in probe(). v16->v17: * Added ret = dev_err_probe() to avoid return success in probe(). * Dropped unneeded MODULE_ALIAS(). * Dropped .owner from struct rzg2l_gpt_ops. * Fixed build issue reported by kernel test robot by replacing DIV_ROUND_UP()->DIV64_U64_ROUND_UP() in rzg2l_gpt_calculate_pv_or_dc(). * Added max_val to struct rzg2l_gpt_chip to compute maximum period supported by the HW in probe() and limit its value in apply() to avoid 64-bit overflow with computation. * Added helper function calculate_period_or_duty() to avoid losing precision for smaller period/duty cycle values ((2^32 * 10^9 << 2) < 2^64), by not processing the rounded values. * Replaced mul_u64_u64_div_u64()->mul_u64_u32_div() as the former is giving warnings with CONFIG_PWM_DEBUG enabled for very high values. eg: echo "###### Medium setting 11000 sec = 3hours ##" echo 11000000000000 > /sys/class/pwm/$PWMCHIP/pwm${IO_1}/period echo 5500000000000 > /sys/class/pwm/$PWMCHIP/pwm${IO_1}/duty_cycle dumpgptreg echo "###### High setting##" echo 43980465100800 > /sys/class/pwm/$PWMCHIP/pwm${IO_1}/period echo 23980465100800 > /sys/class/pwm/$PWMCHIP/pwm${IO_1}/duty_cycle dumpgptreg with mul_u64_u32_div(): ###### Medium setting 11000 sec = 3hours ## Read at address 0x10048464 (0xffffb9426464): 0x400746FE Read at address 0x1004844C (0xffff8fdfb44c): 0x2003A37F Read at address 0x1004842C (0xffff9855b42c): 0x05000001 ###### High setting## Read at address 0x10048464 (0xffff9101b464): 0xFFFFFFFF Read at address 0x1004844C (0xffffaee0544c): 0x8B95AD77 Read at address 0x1004842C (0xffffbbc8a42c): 0x05000001 with mul_u64_u64_div_u64(): ###### Medium setting 11000 sec = 3hours ## Read at address 0x10048464 (0xffffb3185464): 0x400746FE Read at address 0x1004844C (0xffff81ebb44c): 0x2003A37F Read at address 0x1004842C (0xffff904fd42c): 0x05000001 ######[ 304.213944] pwm-rzg2l-gpt 10048000.pwm: .apply is not idempotent (ena=1 pol=0 5500000000000/43980352512000) -> (ena=1 pol=0 5500000000000/43980239923200) High setting## [ 304.230854] pwm-rzg2l-gpt 10048000.pwm: .apply is not idempotent (ena=1 pol=0 23980465100800/43980352512000) -> (ena=1 pol=0 23980465100800/43980239923200) Read at address 0x10048464 (0xffffb5bb3464): 0xFFFFAA19 Read at address 0x1004844C (0xffff99b8c44c): 0x8B95AD77 Read at address 0x1004842C (0xffffbba2342c): 0x05000001 v15->v16: * Replaced the macro DIV_ROUND_UP_ULL->DIV64_U64_ROUND_UP * Added DIV_ROUND_UP in rzg2l_gpt_calculate_pv_or_dc() to avoid loss of precision. * Replaced min->min_t() in rzg2l_gpt_calculate_pv_or_dc(). * Added a comment for rzg2l_gpt_config() * Replaced mul_u64_u32_div()->mul_u64_u64_div_u64() in rzg2l_gpt_config() * Fixed the logical condition related to counter stop in rzg2l_gpt_config(). * Dropped pm_runtime_resume_*() from rzg2l_gpt_config() as it is managed by rzg2l_gpt_apply(). * Moved pm_runtime_resume_*() from rzg2l_gpt_{en,dis}able() to rzg2l_gpt_apply(). 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 | 473 ++++++++++++++++++++++++++++++++++++ 3 files changed, 485 insertions(+) create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 0915c1e7df16..38fc77a9ed16 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -540,6 +540,17 @@ 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 diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 9081e0c0e9e0..39c029dd3af9 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -49,6 +49,7 @@ 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..28ed39eecb93 --- /dev/null +++ b/drivers/pwm/pwm-rzg2l-gpt.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L General PWM Timer (GPT) driver + * + * Copyright (C) 2024 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. + * - General PWM Timer (GPT) has 8 HW channels for PWM operations and + * each HW channel have 2 IOs. + * - Each IO is modelled as an independent PWM channel. + * - 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_GET_CH(a) ((a) / 2) +#define RZG2L_GET_CH_OFFS(i) (0x100 * (i)) + +#define RZG2L_GTCR(ch) (0x2c + RZG2L_GET_CH_OFFS(ch)) +#define RZG2L_GTUDDTYC(ch) (0x30 + RZG2L_GET_CH_OFFS(ch)) +#define RZG2L_GTIOR(ch) (0x34 + RZG2L_GET_CH_OFFS(ch)) +#define RZG2L_GTBER(ch) (0x40 + RZG2L_GET_CH_OFFS(ch)) +#define RZG2L_GTCNT(ch) (0x48 + RZG2L_GET_CH_OFFS(ch)) +#define RZG2L_GTCCR(ch, sub_ch) (0x4c + RZG2L_GET_CH_OFFS(ch) + 4 * (sub_ch)) +#define RZG2L_GTPR(ch) (0x64 + RZG2L_GET_CH_OFFS(ch)) + +#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_GTUDDTYC_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_GTIOx(a) ((a) ? RZG2L_GTIOR_GTIOB : RZG2L_GTIOR_GTIOA) +#define RZG2L_GTIOR_OAE BIT(8) +#define RZG2L_GTIOR_OBE BIT(24) +#define RZG2L_GTIOR_OxE(a) ((a) ? RZG2L_GTIOR_OBE : RZG2L_GTIOR_OAE) + +#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_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_GTIOx_OUT_HI_END_TOGGLE_CMP_MATCH(a) \ + ((a) ? RZG2L_GTIOR_GTIOB_OUT_HI_END_TOGGLE_CMP_MATCH : \ + RZG2L_GTIOR_GTIOA_OUT_HI_END_TOGGLE_CMP_MATCH) + +#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_MAX_SCALE_FACTOR 1024 +#define RZG2L_MAX_TICKS ((u64)U32_MAX * RZG2L_MAX_SCALE_FACTOR) + +struct rzg2l_gpt_chip { + void __iomem *mmio; + struct mutex lock; /* lock to protect shared channel resources */ + unsigned long rate_khz; + u32 period_ticks[RZG2L_MAX_HW_CHANNELS]; + u32 user_count[RZG2L_MAX_HW_CHANNELS]; + u32 enable_count[RZG2L_MAX_HW_CHANNELS]; +}; + +static inline struct rzg2l_gpt_chip *to_rzg2l_gpt_chip(struct pwm_chip *chip) +{ + return pwmchip_get_drvdata(chip); +} + +static inline unsigned int rzg2l_gpt_subchannel(unsigned int hwpwm) +{ + return hwpwm & 0x1; +} + +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_ticks) +{ + u32 prescaled_period_ticks; + u8 prescale; + + prescaled_period_ticks = period_ticks >> 32; + if (prescaled_period_ticks >= 256) + prescale = 5; + else + prescale = (fls(prescaled_period_ticks) + 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); + + guard(mutex)(&rzg2l_gpt->lock); + rzg2l_gpt->user_count[ch]++; + + 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); + + guard(mutex)(&rzg2l_gpt->lock); + rzg2l_gpt->user_count[ch]--; +} + +static bool rzg2l_gpt_is_ch_enabled(struct rzg2l_gpt_chip *rzg2l_gpt, u8 hwpwm) +{ + u8 ch = RZG2L_GET_CH(hwpwm); + u32 val; + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR(ch)); + if (!(val & RZG2L_GTCR_CST)) + return false; + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTIOR(ch)); + + return val & RZG2L_GTIOR_OxE(rzg2l_gpt_subchannel(hwpwm)); +} + +/* Caller holds the lock while calling rzg2l_gpt_enable() */ +static void rzg2l_gpt_enable(struct rzg2l_gpt_chip *rzg2l_gpt, + struct pwm_device *pwm) +{ + u8 sub_ch = rzg2l_gpt_subchannel(pwm->hwpwm); + u32 val = RZG2L_GTIOR_GTIOx(sub_ch) | RZG2L_GTIOR_OxE(sub_ch); + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + + /* Enable pin output */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTIOR(ch), val, + RZG2L_GTIOR_GTIOx_OUT_HI_END_TOGGLE_CMP_MATCH(sub_ch)); + + if (!rzg2l_gpt->enable_count[ch]) + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR(ch), 0, RZG2L_GTCR_CST); + + rzg2l_gpt->enable_count[ch]++; +} + +/* Caller holds the lock while calling rzg2l_gpt_disable() */ +static void rzg2l_gpt_disable(struct rzg2l_gpt_chip *rzg2l_gpt, + struct pwm_device *pwm) +{ + u8 sub_ch = rzg2l_gpt_subchannel(pwm->hwpwm); + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + + /* Stop count, Output low on GTIOCx pin when counting stops */ + rzg2l_gpt->enable_count[ch]--; + + if (!rzg2l_gpt->enable_count[ch]) + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR(ch), RZG2L_GTCR_CST, 0); + + /* Disable pin output */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTIOR(ch), RZG2L_GTIOR_OxE(sub_ch), 0); +} + +static u64 calculate_period_or_duty(struct rzg2l_gpt_chip *rzg2l_gpt, u32 val, u8 prescale) +{ + u64 tmp; + + /* + * The calculation doesn't overflow an u64 because prescale ≤ 5 and so + * tmp = val << (2 * prescale) * USEC_PER_SEC + * < 2^32 * 2^10 * 10^6 + * < 2^32 * 2^10 * 2^20 + * = 2^62 + */ + tmp = (u64)val << (2 * prescale); + tmp *= USEC_PER_SEC; + + return DIV64_U64_ROUND_UP(tmp, rzg2l_gpt->rate_khz); +} + +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); + + state->enabled = rzg2l_gpt_is_ch_enabled(rzg2l_gpt, pwm->hwpwm); + if (state->enabled) { + u32 sub_ch = rzg2l_gpt_subchannel(pwm->hwpwm); + u32 ch = RZG2L_GET_CH(pwm->hwpwm); + u8 prescale; + u32 val; + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR(ch)); + prescale = FIELD_GET(RZG2L_GTCR_TPCS, val); + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTPR(ch)); + state->period = calculate_period_or_duty(rzg2l_gpt, val, prescale); + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCCR(ch, sub_ch)); + state->duty_cycle = calculate_period_or_duty(rzg2l_gpt, val, prescale); + if (state->duty_cycle > state->period) + state->duty_cycle = state->period; + } + + state->polarity = PWM_POLARITY_NORMAL; + + return 0; +} + +static u32 rzg2l_gpt_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 prescale) +{ + return min_t(u64, DIV_ROUND_DOWN_ULL(period_or_duty_cycle, 1 << (2 * prescale)), + U32_MAX); +} + +/* Caller holds the lock while calling rzg2l_gpt_config() */ +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 sub_ch = rzg2l_gpt_subchannel(pwm->hwpwm); + u8 ch = RZG2L_GET_CH(pwm->hwpwm); + u64 period_ticks, duty_ticks; + unsigned long pv, dc; + u8 prescale; + + /* Limit period/duty cycle to max value supported by the HW */ + period_ticks = mul_u64_u64_div_u64(state->period, rzg2l_gpt->rate_khz, USEC_PER_SEC); + if (period_ticks > RZG2L_MAX_TICKS) + period_ticks = RZG2L_MAX_TICKS; + /* + * 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 (rzg2l_gpt->user_count[ch] > 1 && period_ticks < rzg2l_gpt->period_ticks[ch]) + return -EBUSY; + + prescale = rzg2l_gpt_calculate_prescale(rzg2l_gpt, period_ticks); + pv = rzg2l_gpt_calculate_pv_or_dc(period_ticks, prescale); + + duty_ticks = mul_u64_u64_div_u64(state->duty_cycle, rzg2l_gpt->rate_khz, USEC_PER_SEC); + if (duty_ticks > RZG2L_MAX_TICKS) + duty_ticks = RZG2L_MAX_TICKS; + dc = rzg2l_gpt_calculate_pv_or_dc(duty_ticks, prescale); + + /* + * GPT counter is shared by multiple channels, we cache the period ticks + * from the first enabled channel and use the same value for both + * channels. + */ + rzg2l_gpt->period_ticks[ch] = period_ticks; + + /* + * 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, RZG2L_GTCR(ch), RZG2L_GTCR_CST, 0); + + /* GPT set operating mode (saw-wave up-counting) */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR(ch), RZG2L_GTCR_MD, + RZG2L_GTCR_MD_SAW_WAVE_PWM_MODE); + + /* Set count direction */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTUDDTYC(ch), RZG2L_GTUDDTYC_UP_COUNTING); + + /* Select count clock */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR(ch), RZG2L_GTCR_TPCS, + FIELD_PREP(RZG2L_GTCR_TPCS, prescale)); + + /* Set period */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTPR(ch), pv); + } + + /* Set duty cycle */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTCCR(ch, sub_ch), dc); + + if (rzg2l_gpt->enable_count[ch] <= 1) { + /* Set initial value for counter */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTCNT(ch), 0); + + /* Set no buffer operation */ + rzg2l_gpt_write(rzg2l_gpt, RZG2L_GTBER(ch), 0); + + /* Restart the counter after updating the registers */ + rzg2l_gpt_modify(rzg2l_gpt, RZG2L_GTCR(ch), + RZG2L_GTCR_CST, RZG2L_GTCR_CST); + } + + 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; + + guard(mutex)(&rzg2l_gpt->lock); + if (!state->enabled) { + if (enabled) + rzg2l_gpt_disable(rzg2l_gpt, pwm); + + return 0; + } + + ret = rzg2l_gpt_config(chip, pwm, state); + if (!ret && !enabled) + 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, +}; + +static void rzg2l_gpt_reset_assert(void *data) +{ + reset_control_assert(data); +} + +static int rzg2l_gpt_probe(struct platform_device *pdev) +{ + struct rzg2l_gpt_chip *rzg2l_gpt; + struct device *dev = &pdev->dev; + struct reset_control *rstc; + struct pwm_chip *chip; + unsigned long rate; + struct clk *clk; + int ret; + u32 i; + + chip = devm_pwmchip_alloc(dev, RZG2L_MAX_PWM_CHANNELS, sizeof(*rzg2l_gpt)); + if (IS_ERR(chip)) + return PTR_ERR(chip); + rzg2l_gpt = to_rzg2l_gpt_chip(chip); + + rzg2l_gpt->mmio = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rzg2l_gpt->mmio)) + return PTR_ERR(rzg2l_gpt->mmio); + + rstc = devm_reset_control_get_exclusive(dev, NULL); + if (IS_ERR(rstc)) + return dev_err_probe(dev, PTR_ERR(rstc), "get reset failed\n"); + + clk = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "cannot get clock\n"); + + ret = devm_clk_rate_exclusive_get(dev, clk); + if (ret) + return ret; + + rate = clk_get_rate(clk); + if (!rate) + return dev_err_probe(dev, -EINVAL, "gpt clk rate is 0"); + + /* + * Refuse clk rates > 1 GHz to prevent overflow later for computing + * period and duty cycle. + */ + if (rate > NSEC_PER_SEC) + return dev_err_probe(dev, -EINVAL, "gpt clk rate is > 1GHz"); + + /* + * Rate is in MHz and is always integer for peripheral clk + * 2^32 * 2^10 (prescalar) * 10^6 (rate_khz) < 2^64 + * So make sure rate is multiple of 1000. + */ + rzg2l_gpt->rate_khz = rate / KILO; + if (rzg2l_gpt->rate_khz * KILO != rate) + return dev_err_probe(dev, -EINVAL, "rate is not multiple of 1000"); + + ret = reset_control_deassert(rstc); + if (ret) + return dev_err_probe(dev, ret, "cannot deassert reset control\n"); + + ret = devm_add_action_or_reset(dev, rzg2l_gpt_reset_assert, rstc); + if (ret) + return ret; + + /* + * 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)) { + u8 ch = RZG2L_GET_CH(i); + u8 prescale; + u32 val; + + val = rzg2l_gpt_read(rzg2l_gpt, RZG2L_GTCR(ch)); + prescale = FIELD_GET(RZG2L_GTCR_TPCS, val); + if (prescale > 5) + dev_warn_once(dev, "Invalid prescale set %d > 5", prescale); + + rzg2l_gpt->enable_count[ch]++; + } + } + + mutex_init(&rzg2l_gpt->lock); + + chip->ops = &rzg2l_gpt_ops; + ret = devm_pwmchip_add(dev, chip); + if (ret) + return dev_err_probe(dev, ret, "failed to add PWM chip\n"); + + return 0; +} + +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", + .of_match_table = 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");