Re: [PATCH v6 3/3] drivers: soc: xilinx: Add ZynqMP PM driver

Sudeep Holla
2019-01-30T10:12:49Z

On Tue, Jan 29, 2019 at 12:38:21PM -0800, Jolly Shah wrote:
> From: Rajan Vaja <rajan.vaja@xilinx.com>
>
> Add ZynqMP PM driver. PM driver provides power management
> support for ZynqMP.
>
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> Signed-off-by: Jolly Shah <jollys@xilinx.com>
> ---
> drivers/soc/xilinx/Kconfig | 11 +++
> drivers/soc/xilinx/Makefile | 1 +
> drivers/soc/xilinx/zynqmp_power.c | 178 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 190 insertions(+)
> create mode 100644 drivers/soc/xilinx/zynqmp_power.c
>
> diff --git a/drivers/soc/xilinx/Kconfig b/drivers/soc/xilinx/Kconfig
> index 687c8f3..5025e0e 100644
> --- a/drivers/soc/xilinx/Kconfig
> +++ b/drivers/soc/xilinx/Kconfig
> @@ -17,4 +17,15 @@ config XILINX_VCU
> To compile this driver as a module, choose M here: the
> module will be called xlnx_vcu.
>
> +config ZYNQMP_POWER
> + bool "Enable Xilinx Zynq MPSoC Power Management driver"
> + depends on PM && ARCH_ZYNQMP
> + default y
> + help
> + Say yes to enable power management support for ZyqnMP SoC.
> + This driver uses firmware driver as an interface for power
> + management request to firmware. It registers isr to handle
> + power management callbacks from firmware.
> + If in doubt, say N.
> +
> endmenu
> diff --git a/drivers/soc/xilinx/Makefile b/drivers/soc/xilinx/Makefile
> index dee8fd5..428b9db 100644
> --- a/drivers/soc/xilinx/Makefile
> +++ b/drivers/soc/xilinx/Makefile
> @@ -1,2 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_XILINX_VCU) += xlnx_vcu.o
> +obj-$(CONFIG_ZYNQMP_POWER) += zynqmp_power.o
> diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
> new file mode 100644
> index 0000000..771cb59
> --- /dev/null
> +++ b/drivers/soc/xilinx/zynqmp_power.c
> @@ -0,0 +1,178 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Zynq MPSoC Power Management
> + *
> + * Copyright (C) 2014-2018 Xilinx, Inc.
> + *
> + * Davorin Mista <davorin.mista@aggios.com>
> + * Jolly Shah <jollys@xilinx.com>
> + * Rajan Vaja <rajan.vaja@xilinx.com>
> + */
> +
> +#include <linux/mailbox_client.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include <linux/suspend.h>
> +
> +#include <linux/firmware/xlnx-zynqmp.h>
> +
> +enum pm_suspend_mode {
> + PM_SUSPEND_MODE_FIRST = 0,
> + PM_SUSPEND_MODE_STD = PM_SUSPEND_MODE_FIRST,
> + PM_SUSPEND_MODE_POWER_OFF,
> +};
> +
> +#define PM_SUSPEND_MODE_FIRST PM_SUSPEND_MODE_STD
> +
> +static const char *const suspend_modes[] = {
> + [PM_SUSPEND_MODE_STD] = "standard",
> + [PM_SUSPEND_MODE_POWER_OFF] = "power-off",
> +};
> +
> +static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
> +
> +enum pm_api_cb_id {
> + PM_INIT_SUSPEND_CB = 30,
> + PM_ACKNOWLEDGE_CB,
> + PM_NOTIFY_CB,
> +};
> +
> +static void zynqmp_pm_get_callback_data(u32 *buf)
> +{
> + zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
> +}
> +
> +static irqreturn_t zynqmp_pm_isr(int irq, void *data)
> +{
> + u32 payload[CB_PAYLOAD_SIZE];
> +
> + zynqmp_pm_get_callback_data(payload);
> +
> + /* First element is callback API ID, others are callback arguments */
> + if (payload[0] == PM_INIT_SUSPEND_CB) {
> + switch (payload[1]) {
> + case SUSPEND_SYSTEM_SHUTDOWN:
> + orderly_poweroff(true);
> + break;
> + case SUSPEND_POWER_REQUEST:
> + pm_suspend(PM_SUSPEND_MEM);
> + break;
> + default:
> + pr_err("%s Unsupported InitSuspendCb reason "
> + "code %d\n", __func__, payload[1]);
> + }
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static ssize_t suspend_mode_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + char *s = buf;
> + int md;
> +
> + for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
> + if (suspend_modes[md]) {
> + if (md == suspend_mode)
> + s += sprintf(s, "[%s] ", suspend_modes[md]);
> + else
> + s += sprintf(s, "%s ", suspend_modes[md]);
> + }
> +
> + /* Convert last space to newline */
> + if (s != buf)
> + *(s - 1) = '\n';
> + return (s - buf);
> +}
> +
> +static ssize_t suspend_mode_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + int md, ret = -EINVAL;
> + const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
> +
> + if (!eemi_ops || !eemi_ops->set_suspend_mode)
> + return ret;
> +
> + for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
> + if (suspend_modes[md] &&
> + sysfs_streq(suspend_modes[md], buf)) {
> + ret = 0;
> + break;
> + }
> +
> + if (!ret && md != suspend_mode) {
> + ret = eemi_ops->set_suspend_mode(md);
> + if (likely(!ret))
> + suspend_mode = md;
> + }
> +
> + return ret ? ret : count;
> +}
> +
> +static DEVICE_ATTR_RW(suspend_mode);
> +
> +static int zynqmp_pm_probe(struct platform_device *pdev)
> +{
> + int ret, irq;
> + u32 pm_api_version;
> +
> + const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
> +
> + if (!eemi_ops || !eemi_ops->get_api_version || !eemi_ops->init_finalize)
> + return -ENXIO;
> +
> + eemi_ops->init_finalize();
> + eemi_ops->get_api_version(&pm_api_version);
> +
> + /* Check PM API version number */
> + if (pm_api_version < ZYNQMP_PM_VERSION)
> + return -ENODEV;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq <= 0)
> + return -ENXIO;
> +
> + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, zynqmp_pm_isr,
> + IRQF_NO_SUSPEND | IRQF_ONESHOT,
> + dev_name(&pdev->dev), &pdev->dev);
> + if (ret) {
> + dev_err(&pdev->dev, "devm_request_threaded_irq '%d' failed "
> + "with %d\n", irq, ret);
> + return ret;
> + }
> +
> + ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);

NACK, if this is for system suspend/reset ? You can just use exiting
sysfs, no need to create Xilinx specific new ones. Moreover you need to
use PSCI to make sure higher ELs can do orderly suspend/shutdown.

--
Regards,
Sudeep