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.
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:
* 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 | 553 ++++++++++++++++++
4 files changed, 966 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml
create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c
base-commit: 4f6938e6ed2ee8fffb5ca36d4984beac3c9763a0
--
2.43.0
