Hi Uwe,
> -----Original Message-----
> From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Sent: Thursday, August 8, 2024 2:16 PM
> Subject: [PATCH v21 0/4] Add support for RZ/G2L GPT
>
> 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
>
> This patch series aims to add basic pwm support for RZ/G2L GPT driver by creating separate logical
> channels for each IOs.
>
> 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:
> * 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().
> * Updated copyright from 2023->2024.
> * Moved bitpos near to the user in patch#4.
> 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 <lkp@xxxxxxxxx> 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.
> 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
> * Updated commit description of patch#4 by replacing "This patch add"->
> "Add".
> v13->v14:
> * Moved the patch from series[1] to here.
> [1] https://lore.kernel.org/linux-renesas-soc/20221215205843.4074504-1-
> biju.das.jz@xxxxxxxxxxxxxx/T/#t
> * Add Rb tag from Rob for patch#2
> * 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().
> * Removed the parenthesis for RZG2L_MAX_POEG_GROUPS.
> * Renamed rzg2l_gpt_parse_properties()->rzg2l_gpt_poeg_init() as it
> not only parse the properties but also implements the needed register
> writes.
> * Added acomment here about the purpose of the function
> rzg2l_gpt_poeg_init()
> * Removed magic numbers from rzg2l_gpt_poeg_init()
> * Fixed resource leak in rzg2l_gpt_poeg_init().
> v12->v13:
> * Added test logs in [1] below
> * Replaced Kconfig dependency from ARCH_RENESAS->ARCH_RZG2L
> * Sorted #include <linux/limits.h> 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 example gpt4: pwm@10048400-> gpt: pwm@10048000
> * Keep Rb tag from Rob as the above change is trivial one.
> * 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:
> * Added Rb tag from Rob.
> * 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:
> * Removed Rb tags from Rob and Geert as it modelled as single GPT
> device handling multiple channels.
> * Updated description
> * Updated interrupts and interrupt-names properties
> * Updated binding example
> * Modelled as single PWM device handling multiple channels
> * Replaced shared reset->devm_reset_control_get_exclusive()
> * Added PM runtime callbacks
> * Updated PM handling and removed "pwm_enabled_by_bootloader" variable
> * Replaced iowrite32->writel and ioread32->readl
> * Updated prescale calculation
> * 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, 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 probe error path.
> * 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:
> * Added Rb tag from Rob for the bindings.
> * 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 '|' after 'description:' to preserve formatting.
> * Removed description for pwm_cells as it is common property.
> * Changed the reg size in example from 0xa4->0x100
> * Added Rb tag from Geert for bindings.
> * 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 the driver with PWM_DEBUG enabled.
>
> RFC->v1:
> * Added Description in binding patch
> * Removed comments from reg and clock
> * replaced rzg2l_gpt_write_mask()->rzg2l_gpt_modify()
> * Added rzg2l_gpt_read() and updated macros
> * Removed dtsi patches, will send it separately
>
> RFC:
> * https://lore.kernel.org/linux-renesas-soc/20220430075915.5036-1-biju.das.jz@xxxxxxxxxxxxxx/T/#t
>
>
> Biju Das (4):
> dt-bindings: pwm: Add RZ/G2L GPT binding
> dt-bindings: pwm: rzg2l-gpt: Document renesas,poegs property
> pwm: Add support for RZ/G2L GPT
> pwm: rzg2l-gpt: Add support for gpt linking with poeg
>
> .../bindings/pwm/renesas,rzg2l-gpt.yaml | 401 +++++++++++
> drivers/pwm/Kconfig | 11 +
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-rzg2l-gpt.c | 626 ++++++++++++++++++
> 4 files changed, 1039 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml
> create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c
Gentle ping. Are you happy with the patch series?
Cheers,
Biju
>
>
> base-commit: 2e8b1b881a36223c337e07c63a52ed6c8a47afc7
> --
> 2.43.0
