From patchwork Tue Jun 22 03:09:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Andersson X-Patchwork-Id: 12336321 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35E46C2B9F4 for ; Tue, 22 Jun 2021 03:09:52 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0794B6112D for ; Tue, 22 Jun 2021 03:09:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0794B6112D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6512D6E0EF; Tue, 22 Jun 2021 03:09:51 +0000 (UTC) Received: from mail-ot1-x32b.google.com (mail-ot1-x32b.google.com [IPv6:2607:f8b0:4864:20::32b]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7985D6E07B for ; Tue, 22 Jun 2021 03:09:50 +0000 (UTC) Received: by mail-ot1-x32b.google.com with SMTP id f3-20020a0568301c23b029044ce5da4794so13260029ote.11 for ; Mon, 21 Jun 2021 20:09:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=JJaXR0MvWTLUMUBxm6vEFmtzzq3mthCeXlJRBUTcj0k=; b=JjFGC6CPjqlXte5fKt+wg8qPPb7RoF6xEWbQtpUeivEI7CVJIhOD8nkxVDBvUaM3bE +9q+NYvGp6FFv84lXRcowgz3f87+O0L4YEbpgiawuezPJs6YAUUvJmNdZ4Iqyz8xycs8 inTuVW3hN35wrWcnsO7aMGmrh3TDPKPsdU4d3HNrLNa8Nqi4HQWLIGIMdKEAvTsfjjj0 thubd0GPQmhiHKlwnKgrPau+SpI5HGN3lSsmd0QJ5zBgIxaaZh/2eGFhFILpxp1p5GRk PWWwOuGx+NZeDbJO+jv9mA/yZVzFJg4neUMYzCFoafsl3jhHCGIU1kIp9pzkEjuN1oIM QspA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=JJaXR0MvWTLUMUBxm6vEFmtzzq3mthCeXlJRBUTcj0k=; b=TwvfA1Cm65iWvJZkK1oQqEcrpXSaTAxGIqcqXFpfmFUj0wE8kZyKCfW2nW3e8rnysU NvWODq5e/+nyqSD7QQ8a9h34PAHz58uhR1wg1lScyqfspGilU1Jz7BCyYbpnlknojnnV xZtdll6YzrvmsNhbB3AdDYcnv3uONyVzGqB6M03tG1SG24JOgIDQsbTWIoBSkwnZX6Sd wlrsKLVfQgwm9Nsjfvav3eFdr/J/S6hcP6C2FqGdPOVKZz9gtziaTXT4SANEKQsBdGXv N2LCBz6nVEtqyFgo9Hec+wzknHHeOB8Mp69fvm35nzUkvETgK5xJWGE75411UeP7GqmW 97Zw== X-Gm-Message-State: AOAM5321AJtAZYci2aixstx1bjVrPHEpLv+ax0UitwGxuHKNsQ/wKyQe M6YOP5xN1ME3YyC5AnW0MTCg3A== X-Google-Smtp-Source: ABdhPJwjJhzKb2EkdUdagJpaCej1dmFSqwYlH+F+rbKPdjgh7NJF6+8WPzYwDKKjEZLT4CS07R07kw== X-Received: by 2002:a9d:6303:: with SMTP id q3mr1126330otk.197.1624331389610; Mon, 21 Jun 2021 20:09:49 -0700 (PDT) Received: from builder.lan (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id d10sm243454oop.3.2021.06.21.20.09.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Jun 2021 20:09:49 -0700 (PDT) From: Bjorn Andersson To: Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= , Lee Jones , Doug Anderson Subject: [PATCH v3 1/2] pwm: Introduce single-PWM of_xlate function Date: Mon, 21 Jun 2021 22:09:47 -0500 Message-Id: <20210622030948.966748-1-bjorn.andersson@linaro.org> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, Jonas Karlman , David Airlie , Robert Foss , dri-devel@lists.freedesktop.org, Neil Armstrong , linux-kernel@vger.kernel.org, Jernej Skrabec , Andrzej Hajda , Laurent Pinchart Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The existing pxa driver and the upcoming addition of PWM support in the TI sn565dsi86 DSI/eDP bridge driver both has a single PWM channel and thereby a need for a of_xlate function with the period as its single argument. Introduce a common helper function in the core that can be used as of_xlate by such drivers and migrate the pxa driver to use this. Signed-off-by: Bjorn Andersson --- Changes since v2: - None drivers/pwm/core.c | 26 ++++++++++++++++++++++++++ drivers/pwm/pwm-pxa.c | 16 +--------------- include/linux/pwm.h | 2 ++ 3 files changed, 29 insertions(+), 15 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index a42999f877d2..5e9c876fccc4 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -152,6 +152,32 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) } EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); +struct pwm_device * +of_pwm_single_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) +{ + struct pwm_device *pwm; + + if (pc->of_pwm_n_cells < 1) + return ERR_PTR(-EINVAL); + + /* validate that one cell is specified, optionally with flags */ + if (args->args_count != 1 && args->args_count != 2) + return ERR_PTR(-EINVAL); + + pwm = pwm_request_from_chip(pc, 0, NULL); + if (IS_ERR(pwm)) + return pwm; + + pwm->args.period = args->args[0]; + pwm->args.polarity = PWM_POLARITY_NORMAL; + + if (args->args_count == 2 && args->args[2] & PWM_POLARITY_INVERTED) + pwm->args.polarity = PWM_POLARITY_INVERSED; + + return pwm; +} +EXPORT_SYMBOL_GPL(of_pwm_single_xlate); + static void of_pwmchip_add(struct pwm_chip *chip) { if (!chip->dev || !chip->dev->of_node) diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c index cfb683827d32..8cd82fb54483 100644 --- a/drivers/pwm/pwm-pxa.c +++ b/drivers/pwm/pwm-pxa.c @@ -148,20 +148,6 @@ static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev) return id ? id->data : NULL; } -static struct pwm_device * -pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) -{ - struct pwm_device *pwm; - - pwm = pwm_request_from_chip(pc, 0, NULL); - if (IS_ERR(pwm)) - return pwm; - - pwm->args.period = args->args[0]; - - return pwm; -} - static int pwm_probe(struct platform_device *pdev) { const struct platform_device_id *id = platform_get_device_id(pdev); @@ -187,7 +173,7 @@ static int pwm_probe(struct platform_device *pdev) pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1; if (IS_ENABLED(CONFIG_OF)) { - pwm->chip.of_xlate = pxa_pwm_of_xlate; + pwm->chip.of_xlate = of_pwm_single_xlate; pwm->chip.of_pwm_n_cells = 1; } diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 5a73251d28e3..6aff1fa4fe5d 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -411,6 +411,8 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args); +struct pwm_device *of_pwm_single_xlate(struct pwm_chip *pc, + const struct of_phandle_args *args); struct pwm_device *pwm_get(struct device *dev, const char *con_id); struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np, From patchwork Tue Jun 22 03:09:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Andersson X-Patchwork-Id: 12336323 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E0F7C2B9F4 for ; Tue, 22 Jun 2021 03:09:55 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3AEB9610EA for ; Tue, 22 Jun 2021 03:09:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3AEB9610EA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A4E2A6E07B; Tue, 22 Jun 2021 03:09:54 +0000 (UTC) Received: from mail-oo1-xc30.google.com (mail-oo1-xc30.google.com [IPv6:2607:f8b0:4864:20::c30]) by gabe.freedesktop.org (Postfix) with ESMTPS id 62F216E07B for ; Tue, 22 Jun 2021 03:09:51 +0000 (UTC) Received: by mail-oo1-xc30.google.com with SMTP id z14-20020a4a984e0000b029024a8c622149so5020388ooi.10 for ; Mon, 21 Jun 2021 20:09:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CvmTCxTozQCqUVDgOanp3wEDX8BVOmRgoXBPDucrzF8=; b=ztAw3BveGOmhmSUBkHvdlsyYAsi+BjpdTeEEa3OtVKKXbjY270NiQxOWJ1E/evJKMB X1FwxQqUOM0t03KHhpIhhV1OQbz7IomG7zMKlbXvdHF2SNTkgXuBqdhNzd18LN90JB74 5ZCxSCcob1EqqWWsuFHDBq1On0gNAsSjve9ly6KncueD89teO4SyorpDMTm7GR2C8rWW FMLG1WBro1rd33B/6Yny7HeaqmOaOifKjggmocHyBAVCZ5b3xAzhm/HaNfS2Jkz7r9v3 ytx07AQEzgpi2IZ8XgjKPdFLhpDIYs3pbAQ92jIxkh+P8hPNgEotKkGlQr0p96cxxyky 2u9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CvmTCxTozQCqUVDgOanp3wEDX8BVOmRgoXBPDucrzF8=; b=oLPkmtPUaQ6TcEBMDEj2MexxR3AHYTyNuEgkzFTgmF3qi7vwHKG0GEfJ/treMVuwP4 9J4ChgE8Ic+8FjJ0tGCm25Qisxb+tEQbTpdISBiZyWXoTw8AJi57GZceuZ3dla5BbxkU +3LzBSbkhNUyyLR73BXXAciiBxcHtatnw2Uy9xl5jLU/wKVeA/09IA7SsBVHwXZs4pyT +ggrLY31QdMzR9rFiBIbILyAZLt1+oIhfmWifeTvp7QdC6OybtPLvOkhbsurVtI2SOLk IzppqwxKIwiRmC2wgU0uqMrIhZ87fzd1RTgjXvyt6Ni6SCJjtQZFNkogrWjM7xNsMYfi 1Tjw== X-Gm-Message-State: AOAM532Cky1K0XUDO1d5un1ZURmzyohUj7Ap2kDYJ8sw9fpF99JS3r7f ZWOrcNZ8YXRhjmICqXzFRaWlfw== X-Google-Smtp-Source: ABdhPJyURqUeLuIhxTxWtYhpC49/d8dR+14ytYGC8rE+gboQtHWLIi8nKkG0hZfv98tP3FZuvEqC2Q== X-Received: by 2002:a4a:b203:: with SMTP id d3mr1231867ooo.55.1624331390571; Mon, 21 Jun 2021 20:09:50 -0700 (PDT) Received: from builder.lan (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id d10sm243454oop.3.2021.06.21.20.09.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Jun 2021 20:09:50 -0700 (PDT) From: Bjorn Andersson To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Lee Jones , Doug Anderson Subject: [PATCH v3 2/2] drm/bridge: ti-sn65dsi86: Implement the pwm_chip Date: Mon, 21 Jun 2021 22:09:48 -0500 Message-Id: <20210622030948.966748-2-bjorn.andersson@linaro.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210622030948.966748-1-bjorn.andersson@linaro.org> References: <20210622030948.966748-1-bjorn.andersson@linaro.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The SN65DSI86 provides the ability to supply a PWM signal on GPIO 4, with the primary purpose of controlling the backlight of the attached panel. Add an implementation that exposes this using the standard PWM framework, to allow e.g. pwm-backlight to expose this to the user. Signed-off-by: Bjorn Andersson --- Changes since v2: - Corrected calculation of scale, to include a 1 instead of 1/NSEC_TO_SEC and rounded the period up in get_state, to make sure its idempotent - Changed duty_cycle calculation to make sure it idempotent over my tested period - Documented "Limitations" - Documented muxing operation after pm_runtime_get_sync() drivers/gpu/drm/bridge/ti-sn65dsi86.c | 335 +++++++++++++++++++++++++- 1 file changed, 334 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index 5d712c8c3c3b..0eabbdad1830 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -4,6 +4,7 @@ * datasheet: https://www.ti.com/lit/ds/symlink/sn65dsi86.pdf */ +#include #include #include #include @@ -15,6 +16,7 @@ #include #include #include +#include #include #include @@ -91,6 +93,13 @@ #define SN_ML_TX_MODE_REG 0x96 #define ML_TX_MAIN_LINK_OFF 0 #define ML_TX_NORMAL_MODE BIT(0) +#define SN_PWM_PRE_DIV_REG 0xA0 +#define SN_BACKLIGHT_SCALE_REG 0xA1 +#define BACKLIGHT_SCALE_MAX 0xFFFF +#define SN_BACKLIGHT_REG 0xA3 +#define SN_PWM_EN_INV_REG 0xA5 +#define SN_PWM_INV_MASK BIT(0) +#define SN_PWM_EN_MASK BIT(1) #define SN_AUX_CMD_STATUS_REG 0xF4 #define AUX_IRQ_STATUS_AUX_RPLY_TOUT BIT(3) #define AUX_IRQ_STATUS_AUX_SHORT BIT(5) @@ -113,11 +122,14 @@ #define SN_LINK_TRAINING_TRIES 10 +#define SN_PWM_GPIO_IDX 3 /* 4th GPIO */ + /** * struct ti_sn65dsi86 - Platform data for ti-sn65dsi86 driver. * @bridge_aux: AUX-bus sub device for MIPI-to-eDP bridge functionality. * @gpio_aux: AUX-bus sub device for GPIO controller functionality. * @aux_aux: AUX-bus sub device for eDP AUX channel functionality. + * @pwm_aux: AUX-bus sub device for PWM controller functionality. * * @dev: Pointer to the top level (i2c) device. * @regmap: Regmap for accessing i2c. @@ -145,11 +157,17 @@ * bitmap so we can do atomic ops on it without an extra * lock so concurrent users of our 4 GPIOs don't stomp on * each other's read-modify-write. + * + * @pchip: pwm_chip if the PWM is exposed. + * @pwm_enabled: Used to track if the PWM signal is currently enabled. + * @pwm_refclk_freq: Cache for the reference clock input to the PWM. + * @pwm_pin_busy: Track if GPIO4 is currently requested for GPIO or PWM. */ struct ti_sn65dsi86 { struct auxiliary_device bridge_aux; struct auxiliary_device gpio_aux; struct auxiliary_device aux_aux; + struct auxiliary_device pwm_aux; struct device *dev; struct regmap *regmap; @@ -172,6 +190,12 @@ struct ti_sn65dsi86 { struct gpio_chip gchip; DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS); #endif +#if defined(CONFIG_PWM) + struct pwm_chip pchip; + bool pwm_enabled; + unsigned int pwm_refclk_freq; + atomic_t pwm_pin_busy; +#endif }; static const struct regmap_range ti_sn65dsi86_volatile_ranges[] = { @@ -190,6 +214,25 @@ static const struct regmap_config ti_sn65dsi86_regmap_config = { .cache_type = REGCACHE_NONE, }; +static int ti_sn65dsi86_read_u16(struct ti_sn65dsi86 *pdata, + unsigned int reg, u16 *val) +{ + unsigned int tmp; + int ret; + + ret = regmap_read(pdata->regmap, reg, &tmp); + if (ret) + return ret; + *val = tmp; + + ret = regmap_read(pdata->regmap, reg + 1, &tmp); + if (ret) + return ret; + *val |= tmp << 8; + + return 0; +} + static void ti_sn65dsi86_write_u16(struct ti_sn65dsi86 *pdata, unsigned int reg, u16 val) { @@ -253,6 +296,14 @@ static void ti_sn_bridge_set_refclk_freq(struct ti_sn65dsi86 *pdata) regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK, REFCLK_FREQ(i)); + +#if defined(CONFIG_PWM) + /* + * The PWM refclk is based on the value written to SN_DPPLL_SRC_REG, + * regardless of its actual sourcing. + */ + pdata->pwm_refclk_freq = ti_sn_bridge_refclk_lut[i]; +#endif } static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata) @@ -1044,6 +1095,258 @@ static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata) return 0; } +#if defined(CONFIG_PWM) +static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) +{ + return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0; +} + +static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) +{ + atomic_set(&pdata->pwm_pin_busy, 0); +} + +static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip) +{ + return container_of(chip, struct ti_sn65dsi86, pchip); +} + +static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip); + + return ti_sn_pwm_pin_request(pdata); +} + +static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip); + + ti_sn_pwm_pin_release(pdata); +} + +/* + * Limitations: + * - The PWM signal is not driven when the chip is powered down, or in its + * reset state and the driver does not implement the "suspend state" + * described in the documentation. In order to save power, state->enabled is + * interpreted as denoting if the signal is expected to be valid, and is used to keep + * the determine if the chip needs to be kept powered. + * - Changing both period and duty_cycle is not done atomically, so the output + * might briefly be a mix of the two settings. + */ +static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip); + unsigned int pwm_en_inv; + unsigned int backlight; + unsigned int pre_div; + unsigned int scale; + u64 tick; + int ret; + + if (!pdata->pwm_enabled) { + ret = pm_runtime_get_sync(pdata->dev); + if (ret < 0) + return ret; + + /* + * The chip might have been powered down while we didn't hold a + * PM runtime reference, so mux in the PWM function on the GPIO + * pin again. + */ + ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG, + SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX), + SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX)); + if (ret) { + dev_err(pdata->dev, "failed to mux in PWM function\n"); + goto out; + } + } + + if (state->enabled) { + /* + * Per the datasheet the PWM frequency is given by: + * + * PWM_FREQ = REFCLK_FREQ / (PWM_PRE_DIV * BACKLIGHT_SCALE + 1) + * + * which can be rewritten: + * + * T_pwm * REFCLK_FREQ - 1 = PWM_PRE_DIV * BACKLIGHT_SCALE + * + * In order to keep BACKLIGHT_SCALE within its 16 bits, + * PWM_PRE_DIV must be: + * + * PWM_PRE_DIV >= (T_pwm * REFCLK_FREQ - 1) / BACKLIGHT_SCALE_MAX; + * + * To simplify the search and optimize the resolution of the + * PWM, the lowest possible PWM_PRE_DIV is used. Finally the + * scale is calculated as: + * + * BACKLIGHT_SCALE = (T_pwm * REFCLK_FREQ - 1) / PWM_PRE_DIV + * + * Here T_pwm is represented in seconds, so appropriate scaling + * to nanoseconds is necessary. + */ + + /* Minimum T_pwm is (1 * 1 + 1) / REFCLK_FREQ */ + if (state->period * pdata->pwm_refclk_freq <= 2 * NSEC_PER_SEC) { + ret = -EINVAL; + goto out; + } + + pre_div = DIV_ROUND_UP((state->period * pdata->pwm_refclk_freq - NSEC_PER_SEC), + (NSEC_PER_SEC * BACKLIGHT_SCALE_MAX)); + if (pre_div > 0xff) + pre_div = 0xff; + + scale = (state->period * pdata->pwm_refclk_freq - NSEC_PER_SEC) / (NSEC_PER_SEC * pre_div); + + /* + * PWM duty cycle is given as: + * + * duty = BACKLIGHT / (BACKLIGHT_SCALE + 1) + * + * The documentation is however inconsistent in its examples, + * so the interpretation used here is that the duty cycle is + * the period of BACKLIGHT * PRE_DIV / REFCLK_FREQ. + * + * The ratio PRE_DIV / REFCLK_FREQ is rounded up to whole + * nanoseconds in order to ensure that the calculations are + * idempotent and gives results that are smaller than the + * requested value. + */ + tick = DIV_ROUND_UP(NSEC_PER_SEC * pre_div, pdata->pwm_refclk_freq); + backlight = state->duty_cycle / tick; + if (backlight > scale) + backlight = scale; + + ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div); + if (ret) { + dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n"); + goto out; + } + + ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale); + ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight); + } + + pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, !!state->enabled) | + FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED); + ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv); + if (ret) { + dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n"); + goto out; + } + + pdata->pwm_enabled = !!state->enabled; +out: + + if (!pdata->pwm_enabled) + pm_runtime_put_sync(pdata->dev); + + return ret; +} + +static void ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip); + unsigned int pwm_en_inv; + unsigned int pre_div; + u16 backlight; + u16 scale; + int ret; + + ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv); + if (ret) + return; + + ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale); + if (ret) + return; + + ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight); + if (ret) + return; + + ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div); + if (ret) + return; + + state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv); + if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv)) + state->polarity = PWM_POLARITY_INVERSED; + else + state->polarity = PWM_POLARITY_NORMAL; + + state->period = DIV_ROUND_UP(NSEC_PER_SEC * (pre_div * scale + 1), pdata->pwm_refclk_freq); + state->duty_cycle = backlight * DIV_ROUND_UP(NSEC_PER_SEC * pre_div, pdata->pwm_refclk_freq); +} + +static const struct pwm_ops ti_sn_pwm_ops = { + .request = ti_sn_pwm_request, + .free = ti_sn_pwm_free, + .apply = ti_sn_pwm_apply, + .get_state = ti_sn_pwm_get_state, + .owner = THIS_MODULE, +}; + +static int ti_sn_pwm_probe(struct auxiliary_device *adev, + const struct auxiliary_device_id *id) +{ + struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent); + + pdata->pchip.dev = pdata->dev; + pdata->pchip.ops = &ti_sn_pwm_ops; + pdata->pchip.npwm = 1; + pdata->pchip.of_xlate = of_pwm_single_xlate; + pdata->pchip.of_pwm_n_cells = 1; + + return pwmchip_add(&pdata->pchip); +} + +static void ti_sn_pwm_remove(struct auxiliary_device *adev) +{ + struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent); + + pwmchip_remove(&pdata->pchip); + + if (pdata->pwm_enabled) + pm_runtime_put_sync(pdata->dev); +} + +static const struct auxiliary_device_id ti_sn_pwm_id_table[] = { + { .name = "ti_sn65dsi86.pwm", }, + {}, +}; + +static struct auxiliary_driver ti_sn_pwm_driver = { + .name = "pwm", + .probe = ti_sn_pwm_probe, + .remove = ti_sn_pwm_remove, + .id_table = ti_sn_pwm_id_table, +}; + +static int __init ti_sn_pwm_register(void) +{ + return auxiliary_driver_register(&ti_sn_pwm_driver); +} + +static void ti_sn_pwm_unregister(void) +{ + auxiliary_driver_unregister(&ti_sn_pwm_driver); +} + +#else +static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; } +static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {} + +static inline int ti_sn_pwm_register(void) { return 0; } +static inline void ti_sn_pwm_unregister(void) {} +#endif + #if defined(CONFIG_OF_GPIO) static int tn_sn_bridge_of_xlate(struct gpio_chip *chip, @@ -1176,10 +1479,26 @@ static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip, return ret; } +static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset) +{ + struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip); + + if (offset == SN_PWM_GPIO_IDX) + return ti_sn_pwm_pin_request(pdata); + + return 0; +} + + static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset) { + struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip); + /* We won't keep pm_runtime if we're input, so switch there on free */ ti_sn_bridge_gpio_direction_input(chip, offset); + + if (offset == SN_PWM_GPIO_IDX) + ti_sn_pwm_pin_release(pdata); } static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = { @@ -1201,6 +1520,7 @@ static int ti_sn_gpio_probe(struct auxiliary_device *adev, pdata->gchip.owner = THIS_MODULE; pdata->gchip.of_xlate = tn_sn_bridge_of_xlate; pdata->gchip.of_gpio_n_cells = 2; + pdata->gchip.request = ti_sn_bridge_gpio_request; pdata->gchip.free = ti_sn_bridge_gpio_free; pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction; pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input; @@ -1500,6 +1820,12 @@ static int ti_sn65dsi86_probe(struct i2c_client *client, return ret; } + if (IS_ENABLED(CONFIG_PWM)) { + ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm"); + if (ret) + return ret; + } + /* * NOTE: At the end of the AUX channel probe we'll add the aux device * for the bridge. This is because the bridge can't be used until the @@ -1543,10 +1869,14 @@ static int __init ti_sn65dsi86_init(void) if (ret) goto err_main_was_registered; - ret = auxiliary_driver_register(&ti_sn_aux_driver); + ret = ti_sn_pwm_register(); if (ret) goto err_gpio_was_registered; + ret = auxiliary_driver_register(&ti_sn_aux_driver); + if (ret) + goto err_pwm_was_registered; + ret = auxiliary_driver_register(&ti_sn_bridge_driver); if (ret) goto err_aux_was_registered; @@ -1555,6 +1885,8 @@ static int __init ti_sn65dsi86_init(void) err_aux_was_registered: auxiliary_driver_unregister(&ti_sn_aux_driver); +err_pwm_was_registered: + ti_sn_pwm_unregister(); err_gpio_was_registered: ti_sn_gpio_unregister(); err_main_was_registered: @@ -1568,6 +1900,7 @@ static void __exit ti_sn65dsi86_exit(void) { auxiliary_driver_unregister(&ti_sn_bridge_driver); auxiliary_driver_unregister(&ti_sn_aux_driver); + ti_sn_pwm_unregister(); ti_sn_gpio_unregister(); i2c_del_driver(&ti_sn65dsi86_driver); }