Some devices need real hard-reset by cutting the power. During power sequence turn off and on the regulator, if it is provided.
Additionally add support for instantiating the pwrseq-simple device on a generic property 'power-sequence'. The device will attach itself to the node containing the property and parse the node's properties like reset-gpios, ext-supply etc. Signed-off-by: Krzysztof Kozlowski <[email protected]> --- .../bindings/power/pwrseq/pwrseq-simple.txt | 29 +++++++- drivers/power/pwrseq/pwrseq_simple.c | 85 +++++++++++++++++++++- 2 files changed, 107 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-simple.txt b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-simple.txt index ce0e76749671..a8c3f13ee83f 100644 --- a/Documentation/devicetree/bindings/power/pwrseq/pwrseq-simple.txt +++ b/Documentation/devicetree/bindings/power/pwrseq/pwrseq-simple.txt @@ -1,11 +1,17 @@ -* The simple MMC power sequence provider +* The simple power sequence provider -The purpose of the simple MMC power sequence provider is to supports a set of +The purpose of the simple power sequence provider is to supports a set of common properties between various SOC designs. It thus enables us to use the same provider for several SOC designs. -Required properties: -- compatible : contains "mmc-pwrseq-simple". +The driver supports two types of bindings: +1. Separate node + Required properties: + - compatible : contains "mmc-pwrseq-simple". + +2. Property for any node + Required properties: + - power-sequence Optional properties: - reset-gpios : contains a list of GPIO specifiers. The reset GPIOs are asserted @@ -16,6 +22,7 @@ Optional properties: See ../clocks/clock-bindings.txt for details. - clock-names : Must include the following entry: "ext_clock" (External clock provided to the card). +- ext-supply : External regulator supply Example: @@ -24,4 +31,18 @@ Example: reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>; clocks = <&clk_32768_ck>; clock-names = "ext_clock"; + ext-supply = <&buck8>; } + + usb3503@08 { + compatible = "smsc,usb3503"; + reg = <0x08>; + + intn-gpios = <&gpx3 0 GPIO_ACTIVE_HIGH>; + connect-gpios = <&gpx3 4 GPIO_ACTIVE_HIGH>; + reset-gpios = <&gpx3 5 GPIO_ACTIVE_HIGH>; + initial-mode = <1>; + + power-sequence; + ext-supply = <&buck8_reg>; + }; diff --git a/drivers/power/pwrseq/pwrseq_simple.c b/drivers/power/pwrseq/pwrseq_simple.c index 93807a6ef162..4096261b16a4 100644 --- a/drivers/power/pwrseq/pwrseq_simple.c +++ b/drivers/power/pwrseq/pwrseq_simple.c @@ -1,12 +1,15 @@ /* - * Copyright (C) 2014 Linaro Ltd + * Copyright (C) 2014 Linaro Ltd + * Copyright (C) 2016 Samsung Electronics * * Author: Ulf Hansson <[email protected]> + * Krzysztof Kozlowski <[email protected]> * * License terms: GNU General Public License (GPL) version 2 * * Simple MMC power sequence management */ +#include <linux/of.h> #include <linux/clk.h> #include <linux/init.h> #include <linux/kernel.h> @@ -16,13 +19,16 @@ #include <linux/device.h> #include <linux/err.h> #include <linux/gpio/consumer.h> +#include <linux/regulator/consumer.h> #include <linux/pwrseq.h> +#include <linux/delay.h> struct mmc_pwrseq_simple { struct pwrseq pwrseq; bool clk_enabled; struct clk *ext_clk; struct gpio_descs *reset_gpios; + struct regulator *ext_reg; }; #define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq) @@ -60,6 +66,13 @@ static void mmc_pwrseq_simple_post_power_on(struct pwrseq *_pwrseq) { struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(_pwrseq); + if (pwrseq->ext_reg) { + int err; + + err = regulator_enable(pwrseq->ext_reg); + WARN_ON_ONCE(err); + } + mmc_pwrseq_simple_set_gpios_value(pwrseq, 0); } @@ -73,6 +86,13 @@ static void mmc_pwrseq_simple_power_off(struct pwrseq *_pwrseq) clk_disable_unprepare(pwrseq->ext_clk); pwrseq->clk_enabled = false; } + + if (pwrseq->ext_reg) { + int err; + + err = regulator_disable(pwrseq->ext_reg); + WARN_ON_ONCE(err); + } } static const struct pwrseq_ops mmc_pwrseq_simple_ops = { @@ -100,12 +120,40 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev) if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT) return PTR_ERR(pwrseq->ext_clk); + pwrseq->ext_reg = devm_regulator_get_optional(dev, "ext"); + if (IS_ERR(pwrseq->ext_reg)) { + if (PTR_ERR(pwrseq->ext_reg) == -ENODEV) + pwrseq->ext_reg = NULL; + else + return PTR_ERR(pwrseq->ext_reg); + } else { + int err; + /* + * Be sure that regulator is off, before the driver will start + * power sequence. It is likely that regulator is on by default + * and it without toggling it here, it would be disabled much + * later by the core. + */ + + err = regulator_enable(pwrseq->ext_reg); + WARN_ON_ONCE(err); + + err = regulator_disable(pwrseq->ext_reg); + WARN_ON_ONCE(err); + } + pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(pwrseq->reset_gpios) && PTR_ERR(pwrseq->reset_gpios) != -ENOENT && PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) { - return PTR_ERR(pwrseq->reset_gpios); + /* + * Don't care about errors. If this pwrseq device was added + * to node with existing reset-gpios, then the GPIO reset will + * be handled by other device. + */ + dev_warn(dev, "Cannot get reset gpio: %ld\n", + PTR_ERR(pwrseq->reset_gpios)); } pwrseq->pwrseq.dev = dev; @@ -122,6 +170,13 @@ static int mmc_pwrseq_simple_remove(struct platform_device *pdev) pwrseq_unregister(&pwrseq->pwrseq); + if (pwrseq->ext_reg) { + int err; + + err = regulator_disable(pwrseq->ext_reg); + WARN_ON_ONCE(err); + } + return 0; } @@ -134,5 +189,29 @@ static struct platform_driver mmc_pwrseq_simple_driver = { }, }; -module_platform_driver(mmc_pwrseq_simple_driver); +static int __init mmc_pwrseq_simple_driver_init(void) +{ + struct platform_device *pdev; + struct device_node *np; + + for_each_node_with_property(np, "power-sequence") { + pdev = platform_device_register_simple("pwrseq_simple", + PLATFORM_DEVID_AUTO, + NULL, 0); + if (!IS_ERR(pdev)) { + of_node_get(np); + pdev->dev.of_node = np; + } + } + + return platform_driver_register(&mmc_pwrseq_simple_driver); +} +module_init(mmc_pwrseq_simple_driver_init); + +static void __exit mmc_pwrseq_simple_driver_exit(void) +{ + /* FIXME: of_node_put? */ + platform_driver_unregister(&mmc_pwrseq_simple_driver); +} +module_exit(mmc_pwrseq_simple_driver_exit); MODULE_LICENSE("GPL v2"); -- 1.9.1
