From e5fabbe43f3f58c40c081dbe982431a088a68d9d Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Tue, 8 Mar 2022 18:09:53 +0800 Subject: [PATCH] pinctrl: mediatek: paris: Support generic PIN_CONFIG_DRIVE_STRENGTH_UA Some of the MediaTek chips that utilize the Paris pinctrl driver library support a lower drive strength (<= 1mA) than the standard drive strength settings (2~16 mA) on certain pins. This was previously supported by the custom MTK_PIN_CONFIG_DRV_ADV parameter along with the "mediatek,drive-strength-adv" device tree property. The drive strength values for this hardware are 125, 250, 500, and 1000 mA, and can be readily described by the existing "drive-strength-microamp" property, which then gets parsed by the generic pinconf library into the parameter PIN_CONFIG_DRIVE_STRENGTH_UA. Add support for PIN_CONFIG_DRIVE_STRENGTH_UA while keeping the old custom parameter around for backward compatibility. Signed-off-by: Chen-Yu Tsai Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20220308100956.2750295-9-wenst@chromium.org Signed-off-by: Linus Walleij --- drivers/pinctrl/mediatek/pinctrl-paris.c | 99 ++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c index f8b7305db4dc..bed98623ecf3 100644 --- a/drivers/pinctrl/mediatek/pinctrl-paris.c +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c @@ -48,6 +48,53 @@ static const char * const mtk_gpio_functions[] = { "func12", "func13", "func14", "func15", }; +/* + * This section supports converting to/from custom MTK_PIN_CONFIG_DRV_ADV + * and standard PIN_CONFIG_DRIVE_STRENGTH_UA pin configs. + * + * The custom value encodes three hardware bits as follows: + * + * | Bits | + * | 2 (E1) | 1 (E0) | 0 (EN) | drive strength (uA) + * ------------------------------------------------ + * | x | x | 0 | disabled, use standard drive strength + * ------------------------------------- + * | 0 | 0 | 1 | 125 uA + * | 0 | 1 | 1 | 250 uA + * | 1 | 0 | 1 | 500 uA + * | 1 | 1 | 1 | 1000 uA + */ +static const int mtk_drv_adv_uA[] = { 125, 250, 500, 1000 }; + +static int mtk_drv_adv_to_uA(int val) +{ + /* This should never happen. */ + if (WARN_ON_ONCE(val < 0 || val > 7)) + return -EINVAL; + + /* Bit 0 simply enables this hardware part */ + if (!(val & BIT(0))) + return -EINVAL; + + return mtk_drv_adv_uA[(val >> 1)]; +} + +static int mtk_drv_uA_to_adv(int val) +{ + switch (val) { + case 125: + return 0x1; + case 250: + return 0x3; + case 500: + return 0x5; + case 1000: + return 0x7; + } + + return -EINVAL; +} + static int mtk_pinmux_gpio_request_enable(struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned int pin) @@ -145,8 +192,35 @@ static int mtk_pinconf_get(struct pinctrl_dev *pctldev, case PIN_CONFIG_DRIVE_STRENGTH: if (!hw->soc->drive_get) break; + + if (hw->soc->adv_drive_get) { + err = hw->soc->adv_drive_get(hw, desc, &ret); + if (!err) { + err = mtk_drv_adv_to_uA(ret); + if (err > 0) { + /* PIN_CONFIG_DRIVE_STRENGTH_UA used */ + err = -EINVAL; + break; + } + } + } + err = hw->soc->drive_get(hw, desc, &ret); break; + case PIN_CONFIG_DRIVE_STRENGTH_UA: + if (!hw->soc->adv_drive_get) + break; + + err = hw->soc->adv_drive_get(hw, desc, &ret); + if (err) + break; + err = mtk_drv_adv_to_uA(ret); + if (err < 0) + break; + + ret = err; + err = 0; + break; case MTK_PIN_CONFIG_TDSEL: case MTK_PIN_CONFIG_RDSEL: reg = (param == MTK_PIN_CONFIG_TDSEL) ? @@ -252,6 +326,15 @@ static int mtk_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin, break; err = hw->soc->drive_set(hw, desc, arg); break; + case PIN_CONFIG_DRIVE_STRENGTH_UA: + if (!hw->soc->adv_drive_set) + break; + + err = mtk_drv_uA_to_adv(arg); + if (err < 0) + break; + err = hw->soc->adv_drive_set(hw, desc, err); + break; case MTK_PIN_CONFIG_TDSEL: case MTK_PIN_CONFIG_RDSEL: reg = (param == MTK_PIN_CONFIG_TDSEL) ? @@ -720,6 +803,8 @@ static int mtk_pconf_group_set(struct pinctrl_dev *pctldev, unsigned group, { struct mtk_pinctrl *hw = pinctrl_dev_get_drvdata(pctldev); struct mtk_pinctrl_group *grp = &hw->groups[group]; + bool drive_strength_uA_found = false; + bool adv_drve_strength_found = false; int i, ret; for (i = 0; i < num_configs; i++) { @@ -728,8 +813,22 @@ static int mtk_pconf_group_set(struct pinctrl_dev *pctldev, unsigned group, pinconf_to_config_argument(configs[i])); if (ret < 0) return ret; + + if (pinconf_to_config_param(configs[i]) == PIN_CONFIG_DRIVE_STRENGTH_UA) + drive_strength_uA_found = true; + if (pinconf_to_config_param(configs[i]) == MTK_PIN_CONFIG_DRV_ADV) + adv_drve_strength_found = true; } + /* + * Disable advanced drive strength mode if drive-strength-microamp + * is not set. However, mediatek,drive-strength-adv takes precedence + * as its value can explicitly request the mode be enabled or not. + */ + if (hw->soc->adv_drive_set && !drive_strength_uA_found && + !adv_drve_strength_found) + hw->soc->adv_drive_set(hw, &hw->soc->pins[grp->pin], 0); + return 0; } -- 2.11.0