From patchwork Sun Aug 11 16:34:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Bianconi X-Patchwork-Id: 13759785 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3DF5FC52D7B for ; Sun, 11 Aug 2024 16:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=17kK0GPDd7QrkucnT0MLzkn81RoZzIj1Cixy0iEmvd4=; b=pbH53urWi++fk9QAixWXTeWQHl xpE+p3m5Yafo+Y2Lzz+PZcWBejfh59nBdEJ+ulffoaGM+0bfWRBrKGBfpPyh3IctMVr0M0NVW8u/E F/1x1CgSrN0idmOGYSm5fq/WRDf9dHYLoUJC9LMU3WMbv4zugGvfEFdzatKG8PLZt/1t4+6B/mfZR 3qCPrwd91uDEf2MFReIkQ2iZUmG23mADO+KA1OUeEIQhbH/e6NRxsJHqnPq+KUL3Dip/+u6Rk+bod Ff0ILvRmIKCmsrSM81M37ZGGR9efpp7hic8Ysie9VykwA2T8asggutg4rL643B3klIngH1eqmM+vo u6Qj/KUQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdBYk-0000000FpPJ-17rH; Sun, 11 Aug 2024 16:36:46 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdBXA-0000000FpAs-1TJO for linux-arm-kernel@lists.infradead.org; Sun, 11 Aug 2024 16:35:10 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 50FA160F77; Sun, 11 Aug 2024 16:35:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F958C32786; Sun, 11 Aug 2024 16:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723394107; bh=BgXbb9spkID426ni0BSbzzKrozs7T/9RqNzxqBJmSoM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z5G3bdCjSvPYqaPm8mqbGKi4umqZ/p1h6HZ92aTfvtXat4UJ8rfuDhTsyjnWstYvx WX4AmbzKSE+CudqSjrK707wKLcrtM54NGxaa9XTP1SxuNkmd3o4KZhaQwoe+zn9U6A Tlabl9Fnq/3kJGEW246k+J7EhYuycBMejKhsRvlpxLFZXoTGEIsR6LNeVRbbwn+cts mSztuLB6njNWkA0crQUD77QeWeGmQwXHvuFNsraOXIKm8n7yClGJenssXrCXiN14EE Zoq7OFNBu0uWQ4+b/i5wka+1/g66QXPYB25h/oMLzBxnJ7HNj2Ve3iIAVP51J9DKoX E6KIy7UZ/usRg== From: Lorenzo Bianconi To: linux-pwm@vger.kernel.org Cc: ukleinek@kernel.org, lorenzo.bianconi83@gmail.com, krzk+dt@kernel.org, robh@kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, upstream@airoha.com, angelogioacchino.delregno@collabora.com, benjamin.larsson@genexis.eu, conor+dt@kernel.org, ansuelsmth@gmail.com Subject: [PATCH v2 2/2] pwm: airoha: Add support for EN7581 SoC Date: Sun, 11 Aug 2024 18:34:32 +0200 Message-ID: X-Mailer: git-send-email 2.46.0 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240811_093508_557862_B7B7925E X-CRM114-Status: GOOD ( 36.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Benjamin Larsson Introduce driver for PWM module available on EN7581 SoC. Signed-off-by: Benjamin Larsson Co-developed-by: Lorenzo Bianconi Signed-off-by: Lorenzo Bianconi --- drivers/pwm/Kconfig | 10 + drivers/pwm/Makefile | 1 + drivers/pwm/pwm-airoha.c | 408 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 419 insertions(+) create mode 100644 drivers/pwm/pwm-airoha.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 1dd7921194f5..0d702b394ea7 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -47,6 +47,16 @@ config PWM_AB8500 To compile this driver as a module, choose M here: the module will be called pwm-ab8500. +config PWM_AIROHA + tristate "Airoha PWM support" + depends on ARCH_AIROHA || COMPILE_TEST + depends on OF + help + Generic PWM framework driver for Airoha SoC. + + To compile this driver as a module, choose M here: the module + will be called pwm-airoha. + config PWM_APPLE tristate "Apple SoC PWM support" depends on ARCH_APPLE || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 90913519f11a..cef216753dd6 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o +obj-$(CONFIG_PWM_AIROHA) += pwm-airoha.o obj-$(CONFIG_PWM_APPLE) += pwm-apple.o obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o diff --git a/drivers/pwm/pwm-airoha.c b/drivers/pwm/pwm-airoha.c new file mode 100644 index 000000000000..ccb648e4a18e --- /dev/null +++ b/drivers/pwm/pwm-airoha.c @@ -0,0 +1,408 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2022 Markus Gothe + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define REG_SGPIO_LED_DATE 0x0000 +#define SGPIO_LED_SHIFT_FLAG BIT(31) +#define SGPIO_LED_DATA GENMASK(16, 0) + +#define REG_SGPIO_CLK_DIVR 0x0004 +#define REG_SGPIO_CLK_DLY 0x0008 + +#define REG_SIPO_FLASH_MODE_CFG 0x000c +#define SERIAL_GPIO_FLASH_MODE BIT(1) +#define SERIAL_GPIO_MODE BIT(0) + +#define REG_GPIO_FLASH_PRD_SET(_n) (0x0004 + ((_n) << 2)) +#define GPIO_FLASH_PRD_MASK(_n) GENMASK(15 + ((_n) << 4), ((_n) << 4)) + +#define REG_GPIO_FLASH_MAP(_n) (0x0014 + ((_n) << 2)) +#define GPIO_FLASH_SETID_MASK(_n) GENMASK(2 + ((_n) << 2), ((_n) << 2)) +#define GPIO_FLASH_EN(_n) BIT(3 + ((_n) << 2)) + +#define REG_SIPO_FLASH_MAP(_n) (0x001c + ((_n) << 2)) + +#define REG_CYCLE_CFG_VALUE(_n) (0x0000 + ((_n) << 2)) +#define WAVE_GEN_CYCLE_MASK(_n) GENMASK(7 + ((_n) << 3), ((_n) << 3)) + +struct airoha_pwm { + void __iomem *sgpio_cfg; + void __iomem *flash_cfg; + void __iomem *cycle_cfg; + + struct device_node *np; + u64 initialized; + + struct { + /* Bitmask of PWM channels using this bucket */ + u64 used; + /* Relative duty cycle, 0-255 */ + u32 duty; + /* In 1/250 s, 1-250 permitted */ + u32 period; + } bucket[8]; +}; + +/* + * The first 16 GPIO pins, GPIO0-GPIO15, are mapped into 16 PWM channels, 0-15. + * The SIPO GPIO pins are 16 pins which are mapped into 17 PWM channels, 16-32. + * However, we've only got 8 concurrent waveform generators and can therefore + * only use up to 8 different combinations of duty cycle and period at a time. + */ +#define PWM_NUM_GPIO 16 +#define PWM_NUM_SIPO 17 + +/* The PWM hardware supports periods between 4 ms and 1 s */ +#define PERIOD_MIN_NS 4000000 +#define PERIOD_MAX_NS 1000000000 +/* It is represented internally as 1/250 s between 1 and 250 */ +#define PERIOD_MIN 1 +#define PERIOD_MAX 250 +/* Duty cycle is relative with 255 corresponding to 100% */ +#define DUTY_FULL 255 + +static u32 airoha_pwm_rmw(struct airoha_pwm *pc, void __iomem *addr, + u32 mask, u32 val) +{ + val |= (readl(addr) & ~mask); + writel(val, addr); + + return val; +} + +#define airoha_pwm_sgpio_rmw(pc, offset, mask, val) \ + airoha_pwm_rmw((pc), (pc)->sgpio_cfg + (offset), (mask), (val)) +#define airoha_pwm_flash_rmw(pc, offset, mask, val) \ + airoha_pwm_rmw((pc), (pc)->flash_cfg + (offset), (mask), (val)) +#define airoha_pwm_cycle_rmw(pc, offset, mask, val) \ + airoha_pwm_rmw((pc), (pc)->cycle_cfg + (offset), (mask), (val)) + +#define airoha_pwm_sgpio_set(pc, offset, val) \ + airoha_pwm_sgpio_rmw((pc), (offset), 0, (val)) +#define airoha_pwm_sgpio_clear(pc, offset, mask) \ + airoha_pwm_sgpio_rmw((pc), (offset), (mask), 0) +#define airoha_pwm_flash_set(pc, offset, val) \ + airoha_pwm_flash_rmw((pc), (offset), 0, (val)) +#define airoha_pwm_flash_clear(pc, offset, mask) \ + airoha_pwm_flash_rmw((pc), (offset), (mask), 0) + +static int airoha_pwm_get_waveform(struct airoha_pwm *pc, u32 duty, u32 period) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) { + if (!pc->bucket[i].used) + continue; + + if (duty == pc->bucket[i].duty && + period == pc->bucket[i].period) + return i; + + /* + * Unlike duty cycle zero, which can be handled by + * disabling PWM, a generator is needed for full duty + * cycle but it can be reused regardless of period + */ + if (duty == DUTY_FULL && pc->bucket[i].duty == DUTY_FULL) + return i; + } + + return -1; +} + +static void airoha_pwm_free_waveform(struct airoha_pwm *pc, unsigned int hwpwm) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) + pc->bucket[i].used &= ~BIT_ULL(hwpwm); +} + +static int airoha_pwm_consume_waveform(struct airoha_pwm *pc, u32 duty, + u32 period, unsigned int hwpwm) +{ + int id = airoha_pwm_get_waveform(pc, duty, period); + + if (id < 0) { + int i; + + /* find an unused waveform generator */ + for (i = 0; i < ARRAY_SIZE(pc->bucket); i++) { + if (!(pc->bucket[i].used & ~BIT_ULL(hwpwm))) { + id = i; + break; + } + } + } + + if (id > 0) { + airoha_pwm_free_waveform(pc, hwpwm); + pc->bucket[id].used |= BIT_ULL(hwpwm); + pc->bucket[id].period = period; + pc->bucket[id].duty = duty; + } + + return id; +} + +static int airoha_pwm_sipo_init(struct airoha_pwm *pc) +{ + u32 clk_divr_val = 3, sipo_clock_delay = 1; + u32 val, sipo_clock_divisor = 32; + + if (!(pc->initialized >> PWM_NUM_GPIO)) + return 0; + + /* Select the right shift register chip */ + if (of_property_read_bool(pc->np, "hc74595")) + airoha_pwm_sgpio_set(pc, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_MODE); + else + airoha_pwm_sgpio_clear(pc, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_MODE); + + if (!of_property_read_u32(pc->np, "sipo-clock-divisor", + &sipo_clock_divisor)) { + switch (sipo_clock_divisor) { + case 4: + clk_divr_val = 0; + break; + case 8: + clk_divr_val = 1; + break; + case 16: + clk_divr_val = 2; + break; + case 32: + clk_divr_val = 3; + break; + default: + return -EINVAL; + } + } + /* Configure shift register timings */ + writel(clk_divr_val, pc->sgpio_cfg + REG_SGPIO_CLK_DIVR); + + of_property_read_u32(pc->np, "sipo-clock-delay", &sipo_clock_delay); + if (sipo_clock_delay < 1 || sipo_clock_delay > sipo_clock_divisor / 2) + return -EINVAL; + + /* + * The actual delay is sclkdly + 1 so subtract 1 from + * sipo-clock-delay to calculate the register value + */ + sipo_clock_delay--; + writel(sipo_clock_delay, pc->sgpio_cfg + REG_SGPIO_CLK_DLY); + + /* + * It it necessary to after muxing explicitly shift out all + * zeroes to initialize the shift register before enabling PWM + * mode because in PWM mode SIPO will not start shifting until + * it needs to output a non-zero value (bit 31 of led_data + * indicates shifting in progress and it must return to zero + * before led_data can be written or PWM mode can be set) + */ + if (readl_poll_timeout(pc->sgpio_cfg + REG_SGPIO_LED_DATE, val, + !(val & SGPIO_LED_SHIFT_FLAG), 10, + 200 * USEC_PER_MSEC)) + return -ETIMEDOUT; + + airoha_pwm_sgpio_clear(pc, REG_SGPIO_LED_DATE, SGPIO_LED_DATA); + if (readl_poll_timeout(pc->sgpio_cfg + REG_SGPIO_LED_DATE, val, + !(val & SGPIO_LED_SHIFT_FLAG), 10, + 200 * USEC_PER_MSEC)) + return -ETIMEDOUT; + + /* Set SIPO in PWM mode */ + airoha_pwm_sgpio_set(pc, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_FLASH_MODE); + + return 0; +} + +static void airoha_pwm_config_waveform(struct airoha_pwm *pc, int index, + u32 duty, u32 period) +{ + u32 mask, val; + + /* Configure frequency divisor */ + mask = WAVE_GEN_CYCLE_MASK(index % 4); + val = (period << __bf_shf(mask)) & mask; + airoha_pwm_cycle_rmw(pc, REG_CYCLE_CFG_VALUE(index / 4), mask, val); + + /* Configure duty cycle */ + duty = ((DUTY_FULL - duty) << 8) | duty; + mask = GPIO_FLASH_PRD_MASK(index % 2); + val = (duty << __bf_shf(mask)) & mask; + airoha_pwm_flash_rmw(pc, REG_GPIO_FLASH_PRD_SET(index / 2), mask, val); +} + +static void airoha_pwm_config_flash_map(struct airoha_pwm *pc, + unsigned int hwpwm, int index) +{ + u32 addr, mask, val; + + if (hwpwm < PWM_NUM_GPIO) { + addr = REG_GPIO_FLASH_MAP(hwpwm / 8); + } else { + addr = REG_SIPO_FLASH_MAP(hwpwm / 8); + hwpwm -= PWM_NUM_GPIO; + } + + if (index < 0) { + /* + * Change of waveform takes effect immediately but + * disabling has some delay so to prevent glitching + * only the enable bit is touched when disabling + */ + airoha_pwm_flash_clear(pc, addr, GPIO_FLASH_EN(hwpwm % 8)); + return; + } + + mask = GPIO_FLASH_SETID_MASK(hwpwm % 8); + val = ((index & 7) << __bf_shf(mask)) & mask; + airoha_pwm_flash_rmw(pc, addr, mask, val); + airoha_pwm_flash_set(pc, addr, GPIO_FLASH_EN(hwpwm % 8)); +} + +static int airoha_pwm_config(struct airoha_pwm *pc, struct pwm_device *pwm, + u64 duty_ns, u64 period_ns, + enum pwm_polarity polarity) +{ + u32 duty, period; + int index = -1; + + duty = clamp_val(div64_u64(DUTY_FULL * duty_ns, period_ns), 0, + DUTY_FULL); + if (polarity == PWM_POLARITY_INVERSED) + duty = DUTY_FULL - duty; + + period = clamp_val(div64_u64(25 * period_ns, 100000000), PERIOD_MIN, + PERIOD_MAX); + if (duty) { + index = airoha_pwm_consume_waveform(pc, duty, period, + pwm->hwpwm); + if (index < 0) + return -EBUSY; + } + + if (!(pc->initialized & BIT_ULL(pwm->hwpwm)) && + pwm->hwpwm >= PWM_NUM_GPIO) + airoha_pwm_sipo_init(pc); + + if (index >= 0) { + airoha_pwm_config_waveform(pc, index, duty, period); + airoha_pwm_config_flash_map(pc, pwm->hwpwm, index); + } else { + airoha_pwm_config_flash_map(pc, pwm->hwpwm, index); + airoha_pwm_free_waveform(pc, pwm->hwpwm); + } + + pc->initialized |= BIT_ULL(pwm->hwpwm); + + return 0; +} + +static void airoha_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct airoha_pwm *pc = pwmchip_get_drvdata(chip); + + /* Disable PWM and release the waveform */ + airoha_pwm_config_flash_map(pc, pwm->hwpwm, -1); + airoha_pwm_free_waveform(pc, pwm->hwpwm); + + pc->initialized &= ~BIT_ULL(pwm->hwpwm); + if (!(pc->initialized >> PWM_NUM_GPIO)) + airoha_pwm_sgpio_clear(pc, REG_SIPO_FLASH_MODE_CFG, + SERIAL_GPIO_FLASH_MODE); + + /* + * Clear the state to force re-initialization the next time + * this PWM channel is used since we cannot retain state in + * hardware due to limited number of waveform generators + */ + memset(&pwm->state, 0, sizeof(pwm->state)); +} + +static int airoha_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct airoha_pwm *pc = pwmchip_get_drvdata(chip); + u64 duty = state->enabled ? state->duty_cycle : 0; + + if (state->period < PERIOD_MIN_NS || state->period > PERIOD_MAX_NS) + return -EINVAL; + + return airoha_pwm_config(pc, pwm, duty, state->period, + state->polarity); +} + +static const struct pwm_ops airoha_pwm_ops = { + .apply = airoha_pwm_apply, + .free = airoha_pwm_free, +}; + +static int airoha_pwm_probe(struct platform_device *pdev) +{ + struct airoha_pwm *pc; + struct pwm_chip *chip; + + chip = devm_pwmchip_alloc(&pdev->dev, PWM_NUM_GPIO + PWM_NUM_SIPO, + sizeof(*pc)); + if (IS_ERR(chip)) + return PTR_ERR(chip); + + pc = pwmchip_get_drvdata(chip); + pc->np = pdev->dev.of_node; + + pc->sgpio_cfg = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pc->sgpio_cfg)) + return PTR_ERR(pc->sgpio_cfg); + + pc->flash_cfg = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(pc->flash_cfg)) + return PTR_ERR(pc->flash_cfg); + + pc->cycle_cfg = devm_platform_ioremap_resource(pdev, 2); + if (IS_ERR(pc->cycle_cfg)) + return PTR_ERR(pc->cycle_cfg); + + chip->ops = &airoha_pwm_ops; + chip->of_xlate = of_pwm_xlate_with_flags; + + return devm_pwmchip_add(&pdev->dev, chip); +} + +static const struct of_device_id airoha_pwm_of_match[] = { + { .compatible = "airoha,en7581-pwm" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, airoha_pwm_of_match); + +static struct platform_driver airoha_pwm_driver = { + .driver = { + .name = "airoha-pwm", + .of_match_table = airoha_pwm_of_match, + }, + .probe = airoha_pwm_probe, +}; +module_platform_driver(airoha_pwm_driver); + +MODULE_AUTHOR("Lorenzo Bianconi "); +MODULE_AUTHOR("Markus Gothe "); +MODULE_AUTHOR("Benjamin Larsson "); +MODULE_DESCRIPTION("Airoha EN7581 PWM driver"); +MODULE_LICENSE("GPL");