[PATCH v3 06/12] power: pwrseq: simple: Add support for regulator and generic property
From: Krzysztof Kozlowski
Date: Wed Jun 01 2016 - 04:10:30 EST
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 <k.kozlowski@xxxxxxxxxxx>
---
.../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 <ulf.hansson@xxxxxxxxxx>
+ * Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
*
* 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