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    Subject[PATCH v4 4/5] soc: ti: Add ti_sci_pm_domains driver
    Date
    Introduce a ti_sci_pm_domains driver to act as a generic pm domain
    provider to allow each device to attach and associate it's ti-sci-id so
    that it can be controlled through the TI SCI protocol.

    This driver implements a simple genpd where each device node has a
    phandle to the power domain node and also must provide an index which
    represents the ID to be passed with TI SCI representing the device using
    a single phandle cell. The driver manually parses the phandle to get the
    cell value. Through this interface the genpd dev_ops start and stop
    hooks will use TI SCI to turn on and off each device as determined by
    pm_runtime usage.

    Signed-off-by: Keerthy <j-keerthy@ti.com>
    Signed-off-by: Nishanth Menon <nm@ti.com>
    Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
    ---
    v3->v4:
    Parse phandle directly instead of reading ti,sci-id property per device.

    MAINTAINERS | 1 +
    arch/arm/mach-keystone/Kconfig | 1 +
    drivers/soc/ti/Kconfig | 12 +++
    drivers/soc/ti/Makefile | 1 +
    drivers/soc/ti/ti_sci_pm_domains.c | 202 +++++++++++++++++++++++++++++++++++++
    5 files changed, 217 insertions(+)
    create mode 100644 drivers/soc/ti/ti_sci_pm_domains.c

    diff --git a/MAINTAINERS b/MAINTAINERS
    index aaf96a9b4cd4..5cce85ade551 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -12385,6 +12385,7 @@ F: drivers/firmware/ti_sci*
    F: include/linux/soc/ti/ti_sci_protocol.h
    F: Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
    F: include/dt-bindings/genpd/k2g.h
    +F: drivers/soc/ti/ti_sci_pm_domains.c

    THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
    M: Hans Verkuil <hverkuil@xs4all.nl>
    diff --git a/arch/arm/mach-keystone/Kconfig b/arch/arm/mach-keystone/Kconfig
    index 554357035f30..db122356b410 100644
    --- a/arch/arm/mach-keystone/Kconfig
    +++ b/arch/arm/mach-keystone/Kconfig
    @@ -10,6 +10,7 @@ config ARCH_KEYSTONE
    select ARCH_SUPPORTS_BIG_ENDIAN
    select ZONE_DMA if ARM_LPAE
    select PINCTRL
    + select PM_GENERIC_DOMAINS if PM
    help
    Support for boards based on the Texas Instruments Keystone family of
    SoCs.
    diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
    index 3557c5e32a93..39e152abe6b9 100644
    --- a/drivers/soc/ti/Kconfig
    +++ b/drivers/soc/ti/Kconfig
    @@ -38,4 +38,16 @@ config WKUP_M3_IPC
    to communicate and use the Wakeup M3 for PM features like suspend
    resume and boots it using wkup_m3_rproc driver.

    +config TI_SCI_PM_DOMAINS
    + tristate "TI SCI PM Domains Driver"
    + depends on TI_SCI_PROTOCOL
    + depends on PM_GENERIC_DOMAINS
    + help
    + Generic power domain implementation for TI device implementing
    + the TI SCI protocol.
    +
    + To compile this as a module, choose M here. The module will be
    + called ti_sci_pm_domains. Note this is needed early in boot before
    + rootfs may be available.
    +
    endif # SOC_TI
    diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile
    index 48ff3a79634f..7d572736c86e 100644
    --- a/drivers/soc/ti/Makefile
    +++ b/drivers/soc/ti/Makefile
    @@ -5,3 +5,4 @@ obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS) += knav_qmss.o
    knav_qmss-y := knav_qmss_queue.o knav_qmss_acc.o
    obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA) += knav_dma.o
    obj-$(CONFIG_WKUP_M3_IPC) += wkup_m3_ipc.o
    +obj-$(CONFIG_TI_SCI_PM_DOMAINS) += ti_sci_pm_domains.o
    diff --git a/drivers/soc/ti/ti_sci_pm_domains.c b/drivers/soc/ti/ti_sci_pm_domains.c
    new file mode 100644
    index 000000000000..b0b283810e72
    --- /dev/null
    +++ b/drivers/soc/ti/ti_sci_pm_domains.c
    @@ -0,0 +1,202 @@
    +/*
    + * TI SCI Generic Power Domain Driver
    + *
    + * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
    + * J Keerthy <j-keerthy@ti.com>
    + * Dave Gerlach <d-gerlach@ti.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 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.
    + */
    +
    +#include <linux/err.h>
    +#include <linux/module.h>
    +#include <linux/mutex.h>
    +#include <linux/of.h>
    +#include <linux/platform_device.h>
    +#include <linux/pm_domain.h>
    +#include <linux/slab.h>
    +#include <linux/soc/ti/ti_sci_protocol.h>
    +
    +/**
    + * struct ti_sci_genpd_dev_data: holds data needed for every device attached
    + * to this genpd
    + * @idx: index of the device that identifies it with the system
    + * control processor.
    + */
    +struct ti_sci_genpd_dev_data {
    + int idx;
    +};
    +
    +/**
    + * struct ti_sci_pm_domain: TI specific data needed for power domain
    + * @ti_sci: handle to TI SCI protocol driver that provides ops to
    + * communicate with system control processor.
    + * @dev: pointer to dev for the driver for devm allocs
    + * @pd: generic_pm_domain for use with the genpd framework
    + */
    +struct ti_sci_pm_domain {
    + const struct ti_sci_handle *ti_sci;
    + struct device *dev;
    + struct generic_pm_domain pd;
    +};
    +
    +#define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
    +
    +/**
    + * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
    + * @dev: pointer to device associated with this genpd
    + *
    + * Returns device_id stored from ti,sci_id property
    + */
    +static int ti_sci_dev_id(struct device *dev)
    +{
    + struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
    + struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
    +
    + return sci_dev_data->idx;
    +}
    +
    +/**
    + * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
    + * @dev: pointer to device associated with this genpd
    + *
    + * Returns ti_sci_handle to be used to communicate with system
    + * control processor.
    + */
    +static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
    +{
    + struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
    + struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
    +
    + return ti_sci_genpd->ti_sci;
    +}
    +
    +/**
    + * ti_sci_dev_start(): genpd device start hook called to turn device on
    + * @dev: pointer to device associated with this genpd to be powered on
    + */
    +static int ti_sci_dev_start(struct device *dev)
    +{
    + const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
    + int idx = ti_sci_dev_id(dev);
    +
    + return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
    +}
    +
    +/**
    + * ti_sci_dev_stop(): genpd device stop hook called to turn device off
    + * @dev: pointer to device associated with this genpd to be powered off
    + */
    +static int ti_sci_dev_stop(struct device *dev)
    +{
    + const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
    + int idx = ti_sci_dev_id(dev);
    +
    + return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
    +}
    +
    +static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
    + struct device *dev)
    +{
    + struct device_node *np = dev->of_node;
    + struct of_phandle_args pd_args;
    + struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
    + const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
    + struct ti_sci_genpd_dev_data *sci_dev_data;
    + struct generic_pm_domain_data *genpd_data;
    + int idx, ret = 0;
    +
    + ret = of_parse_phandle_with_args(np, "power-domains",
    + "#power-domain-cells", 0, &pd_args);
    + if (ret < 0)
    + return ret;
    +
    + if (pd_args.args_count != 1)
    + return -EINVAL;
    +
    + idx = pd_args.args[0];
    +
    + /*
    + * Check the validity of the requested idx, if the index is not valid
    + * the PMMC will return a NAK here and we will not allocate it.
    + */
    + ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
    + if (ret)
    + return -EINVAL;
    +
    + sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
    + if (!sci_dev_data)
    + return -ENOMEM;
    +
    + sci_dev_data->idx = idx;
    +
    + genpd_data = dev_gpd_data(dev);
    + genpd_data->data = sci_dev_data;
    +
    + return 0;
    +}
    +
    +static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
    + struct device *dev)
    +{
    + struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
    + struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
    +
    + kfree(sci_dev_data);
    + genpd_data->data = NULL;
    +}
    +
    +static const struct of_device_id ti_sci_pm_domain_matches[] = {
    + { .compatible = "ti,sci-pm-domain", },
    + { },
    +};
    +MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
    +
    +static int ti_sci_pm_domain_probe(struct platform_device *pdev)
    +{
    + struct device *dev = &pdev->dev;
    + struct device_node *np = dev->of_node;
    + struct ti_sci_pm_domain *ti_sci_pd;
    + int ret;
    +
    + ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
    + if (!ti_sci_pd)
    + return -ENOMEM;
    +
    + ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
    + if (IS_ERR(ti_sci_pd->ti_sci))
    + return PTR_ERR(ti_sci_pd->ti_sci);
    +
    + ti_sci_pd->dev = dev;
    +
    + ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
    + ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
    +
    + ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
    + ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
    +
    + pm_genpd_init(&ti_sci_pd->pd, NULL, true);
    +
    + ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
    +
    + return ret;
    +}
    +
    +static struct platform_driver ti_sci_pm_domains_driver = {
    + .probe = ti_sci_pm_domain_probe,
    + .driver = {
    + .name = "ti_sci_pm_domains",
    + .of_match_table = ti_sci_pm_domain_matches,
    + },
    +};
    +module_platform_driver(ti_sci_pm_domains_driver);
    +MODULE_LICENSE("GPL v2");
    +MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
    +MODULE_AUTHOR("Dave Gerlach");
    --
    2.11.0
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      Last update: 2017-03-07 12:58    [W:4.088 / U:0.032 seconds]
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