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SubjectRe: [PATCH v6 2/8] power: add power sequence library
On Mon, Aug 15, 2016 at 05:13:12PM +0800, Peter Chen wrote:
> We have an well-known problem that the device needs to do some power
> sequence before it can be recognized by related host, the typical
> example like hard-wired mmc devices and usb devices.
>
> This power sequence is hard to be described at device tree and handled by
> related host driver, so we have created a common power sequence
> library to cover this requirement. The core code has supplied
> some common helpers for host driver, and individual power sequence
> libraries handle kinds of power sequence for devices.
>
> pwrseq_generic is intended for general purpose of power sequence, which
> handles gpios and clocks currently, and can cover regulator and pinctrl
> in future. The host driver calls pwrseq_alloc_generic to create
> an generic pwrseq instance.
>
> Signed-off-by: Peter Chen <peter.chen@nxp.com>
> Tested-by Joshua Clayton <stillcompiling@gmail.com>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
> Tested-by: Matthias Kaehlcke <mka@chromium.org>

Hi Greg, Sebastian, Dmitry, and David

I find the code under drivers/power have several subsystems.
Does this power sequence patch set can go git://git.infradead.org/battery-2.6.git?
Or can go the Greg's tree?

Peter

> ---
> MAINTAINERS | 9 ++
> drivers/power/Kconfig | 1 +
> drivers/power/Makefile | 1 +
> drivers/power/pwrseq/Kconfig | 20 ++++
> drivers/power/pwrseq/Makefile | 2 +
> drivers/power/pwrseq/core.c | 62 +++++++++++++
> drivers/power/pwrseq/pwrseq_generic.c | 168 ++++++++++++++++++++++++++++++++++
> include/linux/power/pwrseq.h | 47 ++++++++++
> 8 files changed, 310 insertions(+)
> create mode 100644 drivers/power/pwrseq/Kconfig
> create mode 100644 drivers/power/pwrseq/Makefile
> create mode 100644 drivers/power/pwrseq/core.c
> create mode 100644 drivers/power/pwrseq/pwrseq_generic.c
> create mode 100644 include/linux/power/pwrseq.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1ae6c84..407254b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9283,6 +9283,15 @@ F: include/linux/pm_*
> F: include/linux/powercap.h
> F: drivers/powercap/
>
> +POWER SEQUENCE LIBRARY
> +M: Peter Chen <Peter.Chen@nxp.com>
> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git
> +L: linux-pm@vger.kernel.org
> +S: Maintained
> +F: Documentation/devicetree/bindings/power/pwrseq/
> +F: drivers/power/pwrseq/
> +F: include/linux/power/pwrseq.h/
> +
> POWER SUPPLY CLASS/SUBSYSTEM and DRIVERS
> M: Sebastian Reichel <sre@kernel.org>
> M: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index acd4a15..f6aa4fd 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -515,3 +515,4 @@ endif # POWER_SUPPLY
>
> source "drivers/power/reset/Kconfig"
> source "drivers/power/avs/Kconfig"
> +source "drivers/power/pwrseq/Kconfig"
> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> index e46b75d..4ed2e12 100644
> --- a/drivers/power/Makefile
> +++ b/drivers/power/Makefile
> @@ -74,3 +74,4 @@ obj-$(CONFIG_CHARGER_TPS65217) += tps65217_charger.o
> obj-$(CONFIG_POWER_RESET) += reset/
> obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
> obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o
> +obj-$(CONFIG_POWER_SEQUENCE) += pwrseq/
> diff --git a/drivers/power/pwrseq/Kconfig b/drivers/power/pwrseq/Kconfig
> new file mode 100644
> index 0000000..188729e
> --- /dev/null
> +++ b/drivers/power/pwrseq/Kconfig
> @@ -0,0 +1,20 @@
> +#
> +# Power Sequence library
> +#
> +
> +config POWER_SEQUENCE
> + bool
> +
> +menu "Power Sequence Support"
> +
> +config PWRSEQ_GENERIC
> + bool "Generic power sequence control"
> + depends on OF
> + select POWER_SEQUENCE
> + help
> + It is used for drivers which needs to do power sequence
> + (eg, turn on clock, toggle reset gpio) before the related
> + devices can be found by hardware. This generic one can be
> + used for common power sequence control.
> +
> +endmenu
> diff --git a/drivers/power/pwrseq/Makefile b/drivers/power/pwrseq/Makefile
> new file mode 100644
> index 0000000..ad82389
> --- /dev/null
> +++ b/drivers/power/pwrseq/Makefile
> @@ -0,0 +1,2 @@
> +obj-$(CONFIG_POWER_SEQUENCE) += core.o
> +obj-$(CONFIG_PWRSEQ_GENERIC) += pwrseq_generic.o
> diff --git a/drivers/power/pwrseq/core.c b/drivers/power/pwrseq/core.c
> new file mode 100644
> index 0000000..dcf96c4
> --- /dev/null
> +++ b/drivers/power/pwrseq/core.c
> @@ -0,0 +1,62 @@
> +/*
> + * core.c power sequence core file
> + *
> + * Copyright (C) 2016 Freescale Semiconductor, Inc.
> + * Author: Peter Chen <peter.chen@nxp.com>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/power/pwrseq.h>
> +
> +static DEFINE_MUTEX(pwrseq_list_mutex);
> +static LIST_HEAD(pwrseq_list);
> +
> +int pwrseq_get(struct device_node *np, struct pwrseq *p)
> +{
> + if (p && p->get)
> + return p->get(np, p);
> +
> + return -ENOTSUPP;
> +}
> +EXPORT_SYMBOL(pwrseq_get);
> +
> +int pwrseq_on(struct device_node *np, struct pwrseq *p)
> +{
> + if (p && p->on)
> + return p->on(np, p);
> +
> + return -ENOTSUPP;
> +}
> +EXPORT_SYMBOL(pwrseq_on);
> +
> +void pwrseq_off(struct pwrseq *p)
> +{
> + if (p && p->off)
> + p->off(p);
> +}
> +EXPORT_SYMBOL(pwrseq_off);
> +
> +void pwrseq_put(struct pwrseq *p)
> +{
> + if (p && p->put)
> + p->put(p);
> +}
> +EXPORT_SYMBOL(pwrseq_put);
> +
> +void pwrseq_free(struct pwrseq *p)
> +{
> + if (p && p->free)
> + p->free(p);
> +}
> +EXPORT_SYMBOL(pwrseq_free);
> diff --git a/drivers/power/pwrseq/pwrseq_generic.c b/drivers/power/pwrseq/pwrseq_generic.c
> new file mode 100644
> index 0000000..8af626f
> --- /dev/null
> +++ b/drivers/power/pwrseq/pwrseq_generic.c
> @@ -0,0 +1,168 @@
> +/*
> + * pwrseq_generic.c Generic power sequence handling
> + *
> + * Copyright (C) 2016 Freescale Semiconductor, Inc.
> + * Author: Peter Chen <peter.chen@nxp.com>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/slab.h>
> +
> +#include <linux/power/pwrseq.h>
> +
> +struct pwrseq_generic {
> + struct pwrseq pwrseq;
> + struct gpio_desc *gpiod_reset;
> + struct clk *clks[PWRSEQ_MAX_CLKS];
> +};
> +
> +#define to_generic_pwrseq(p) container_of(p, struct pwrseq_generic, pwrseq)
> +
> +static void pwrseq_generic_free(struct pwrseq *pwrseq)
> +{
> + struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
> +
> + kfree(pwrseq_gen);
> +}
> +
> +static void pwrseq_generic_put(struct pwrseq *pwrseq)
> +{
> + struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
> + int clk;
> +
> + if (pwrseq_gen->gpiod_reset)
> + gpiod_put(pwrseq_gen->gpiod_reset);
> +
> + for (clk = 0; clk < PWRSEQ_MAX_CLKS; clk++)
> + clk_put(pwrseq_gen->clks[clk]);
> +}
> +
> +static void pwrseq_generic_off(struct pwrseq *pwrseq)
> +{
> + struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
> + int clk;
> +
> + for (clk = PWRSEQ_MAX_CLKS - 1; clk >= 0; clk--)
> + clk_disable_unprepare(pwrseq_gen->clks[clk]);
> +}
> +
> +static int pwrseq_generic_on(struct device_node *np, struct pwrseq *pwrseq)
> +{
> + struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
> + int clk, ret = 0;
> + struct gpio_desc *gpiod_reset = pwrseq_gen->gpiod_reset;
> +
> + for (clk = 0; clk < PWRSEQ_MAX_CLKS && pwrseq_gen->clks[clk]; clk++) {
> + ret = clk_prepare_enable(pwrseq_gen->clks[clk]);
> + if (ret) {
> + pr_err("Can't enable clock on %s: %d\n",
> + np->full_name, ret);
> + goto err_disable_clks;
> + }
> + }
> +
> + if (gpiod_reset) {
> + u32 duration_us = 50;
> +
> + of_property_read_u32(np, "reset-duration-us",
> + &duration_us);
> + if (duration_us <= 10)
> + udelay(10);
> + else
> + usleep_range(duration_us, duration_us + 100);
> + gpiod_set_value(gpiod_reset, 0);
> + }
> +
> + return ret;
> +
> +err_disable_clks:
> + while (--clk >= 0)
> + clk_disable_unprepare(pwrseq_gen->clks[clk]);
> +
> + return ret;
> +}
> +
> +static int pwrseq_generic_get(struct device_node *np, struct pwrseq *pwrseq)
> +{
> + struct pwrseq_generic *pwrseq_gen = to_generic_pwrseq(pwrseq);
> + enum of_gpio_flags flags;
> + int reset_gpio, clk, ret = 0;
> +
> + for (clk = 0; clk < PWRSEQ_MAX_CLKS; clk++) {
> + pwrseq_gen->clks[clk] = of_clk_get(np, clk);
> + if (IS_ERR(pwrseq_gen->clks[clk])) {
> + ret = PTR_ERR(pwrseq_gen->clks[clk]);
> + if (ret == -EPROBE_DEFER)
> + goto err_put_clks;
> + pwrseq_gen->clks[clk] = NULL;
> + break;
> + }
> + }
> +
> + reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0, &flags);
> + if (gpio_is_valid(reset_gpio)) {
> + unsigned long gpio_flags;
> +
> + if (flags & OF_GPIO_ACTIVE_LOW)
> + gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_LOW;
> + else
> + gpio_flags = GPIOF_OUT_INIT_HIGH;
> +
> + ret = gpio_request_one(reset_gpio, gpio_flags,
> + "pwrseq-reset-gpios");
> + if (ret)
> + goto err_put_clks;
> +
> + pwrseq_gen->gpiod_reset = gpio_to_desc(reset_gpio);
> + } else {
> + if (reset_gpio == -ENOENT)
> + return 0;
> +
> + ret = reset_gpio;
> + pr_err("Failed to get reset gpio on %s, err = %d\n",
> + np->full_name, reset_gpio);
> + goto err_put_clks;
> + }
> +
> + return ret;
> +
> +err_put_clks:
> + while (--clk >= 0)
> + clk_put(pwrseq_gen->clks[clk]);
> + return ret;
> +}
> +
> +struct pwrseq *pwrseq_alloc_generic(void)
> +{
> + struct pwrseq_generic *pwrseq_gen;
> +
> + pwrseq_gen = kzalloc(sizeof(*pwrseq_gen), GFP_KERNEL);
> + if (!pwrseq_gen)
> + return ERR_PTR(-ENOMEM);
> +
> + pwrseq_gen->pwrseq.get = pwrseq_generic_get;
> + pwrseq_gen->pwrseq.on = pwrseq_generic_on;
> + pwrseq_gen->pwrseq.off = pwrseq_generic_off;
> + pwrseq_gen->pwrseq.put = pwrseq_generic_put;
> + pwrseq_gen->pwrseq.free = pwrseq_generic_free;
> +
> + return &pwrseq_gen->pwrseq;
> +}
> +EXPORT_SYMBOL_GPL(pwrseq_alloc_generic);
> diff --git a/include/linux/power/pwrseq.h b/include/linux/power/pwrseq.h
> new file mode 100644
> index 0000000..ebb2280
> --- /dev/null
> +++ b/include/linux/power/pwrseq.h
> @@ -0,0 +1,47 @@
> +#ifndef __LINUX_PWRSEQ_H
> +#define __LINUX_PWRSEQ_H
> +
> +#include <linux/of.h>
> +
> +#define PWRSEQ_MAX_CLKS 3
> +
> +struct pwrseq {
> + char *name;
> + struct list_head node;
> + int (*get)(struct device_node *np, struct pwrseq *p);
> + int (*on)(struct device_node *np, struct pwrseq *p);
> + void (*off)(struct pwrseq *p);
> + void (*put)(struct pwrseq *p);
> + void (*free)(struct pwrseq *p);
> +};
> +
> +#if IS_ENABLED(CONFIG_POWER_SEQUENCE)
> +int pwrseq_get(struct device_node *np, struct pwrseq *p);
> +int pwrseq_on(struct device_node *np, struct pwrseq *p);
> +void pwrseq_off(struct pwrseq *p);
> +void pwrseq_put(struct pwrseq *p);
> +void pwrseq_free(struct pwrseq *p);
> +#else
> +static inline int pwrseq_get(struct device_node *np, struct pwrseq *p)
> +{
> + return 0;
> +}
> +static inline int pwrseq_on(struct device_node *np, struct pwrseq *p)
> +{
> + return 0;
> +}
> +static inline void pwrseq_off(struct pwrseq *p) {}
> +static inline void pwrseq_put(struct pwrseq *p) {}
> +static inline void pwrseq_free(struct pwrseq *p) {}
> +#endif /* CONFIG_POWER_SEQUENCE */
> +
> +#if IS_ENABLED(CONFIG_PWRSEQ_GENERIC)
> +struct pwrseq *pwrseq_alloc_generic(void);
> +#else
> +static inline struct pwrseq *pwrseq_alloc_generic(void)
> +{
> + return NULL;
> +}
> +#endif /* CONFIG_PWRSEQ_GENERIC */
> +
> +#endif /* __LINUX_PWRSEQ_H */
> --
> 1.9.1
>
> --
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--

Best Regards,
Peter Chen

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