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 series aims to add basic pwm support for RZ/G2L GPT driver by creating separate logical channels for each IOs. 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 (2): dt-bindings: pwm: Add RZ/G2L GPT binding pwm: Add support for RZ/G2L GPT .../bindings/pwm/renesas,rzg2l-gpt.yaml | 129 ++++++ drivers/pwm/Kconfig | 11 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-rzg2l-gpt.c | 371 ++++++++++++++++++ 4 files changed, 512 insertions(+) create mode 100644 Documentation/devicetree/bindings/pwm/renesas,rzg2l-gpt.yaml create mode 100644 drivers/pwm/pwm-rzg2l-gpt.c base-commit: 9250d2f72dc46a808b6aa23bf50dd670f1f52ddc -- 2.25.1
