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    Subject[PATCH 12/18] power: reset: Add AT91 poweroff driver
    Date
    Add a driver to handle the shutdown of the Atmel SoCs. This code used to be
    (and still is) in arch/arm/mach-at91. We didn't removed it yet so that we can
    convert all the boards to using this driver, before removing it entirely in a
    separate patch.

    Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
    ---
    drivers/power/reset/Kconfig | 7 ++
    drivers/power/reset/Makefile | 1 +
    drivers/power/reset/at91-poweroff.c | 156 ++++++++++++++++++++++++++++++++++++
    3 files changed, 164 insertions(+)
    create mode 100644 drivers/power/reset/at91-poweroff.c

    diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
    index b3fef01d7cbb..f9d53af50ec0 100644
    --- a/drivers/power/reset/Kconfig
    +++ b/drivers/power/reset/Kconfig
    @@ -14,6 +14,13 @@ config POWER_RESET_AS3722
    help
    This driver supports turning off board via a ams AS3722 power-off.

    +config POWER_RESET_AT91_POWEROFF
    + bool "Atmel AT91 poweroff driver"
    + default SOC_AT91SAM9 || SOC_SAMA5
    + help
    + This driver supports poweroff for Atmel AT91SAM9 and SAMA5
    + SoCs
    +
    config POWER_RESET_AT91_RESET
    bool "Atmel AT91 reset driver"
    default SOC_AT91SAM9 || SOC_SAMA5
    diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
    index 1599214b91d9..8bf941bac3da 100644
    --- a/drivers/power/reset/Makefile
    +++ b/drivers/power/reset/Makefile
    @@ -1,4 +1,5 @@
    obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
    +obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o
    obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o
    obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
    obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
    diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
    new file mode 100644
    index 000000000000..2f2a69e9bae3
    --- /dev/null
    +++ b/drivers/power/reset/at91-poweroff.c
    @@ -0,0 +1,156 @@
    +/*
    + * Atmel AT91 SAM9 SoCs reset code
    + *
    + * Copyright (C) 2014 Maxime Ripard
    + *
    + * Maxime Ripard <maxime.ripard@free-electrons.com>
    + *
    + * This file is licensed under the terms of the GNU General Public
    + * License version 2. This program is licensed "as is" without any
    + * warranty of any kind, whether express or implied.
    + */
    +
    +#include <linux/io.h>
    +#include <linux/module.h>
    +#include <linux/of.h>
    +#include <linux/platform_device.h>
    +#include <linux/printk.h>
    +
    +#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
    +#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */
    +#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */
    +
    +#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */
    +#define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */
    +#define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */
    +#define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */
    +#define AT91_SHDW_CPTWK0_(x) ((x) << 4)
    +#define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */
    +#define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */
    +
    +#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */
    +#define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */
    +#define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */
    +#define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */
    +
    +enum wakeup_type {
    + AT91_SHDW_WKMODE0_NONE = 0,
    + AT91_SHDW_WKMODE0_HIGH = 1,
    + AT91_SHDW_WKMODE0_LOW = 2,
    + AT91_SHDW_WKMODE0_ANYLEVEL = 3,
    +};
    +
    +static const char *shdwc_wakeup_modes[] = {
    + [AT91_SHDW_WKMODE0_NONE] = "none",
    + [AT91_SHDW_WKMODE0_HIGH] = "high",
    + [AT91_SHDW_WKMODE0_LOW] = "low",
    + [AT91_SHDW_WKMODE0_ANYLEVEL] = "any",
    +};
    +
    +static void __iomem *at91_shdwc_base;
    +
    +static void __init at91_wakeup_status(void)
    +{
    + u32 reg = readl(at91_shdwc_base);
    + char *reason = "unknown";
    +
    + /* Simple power-on, just bail out */
    + if (!reg)
    + return;
    +
    + if (reg & AT91_SHDW_RTTWK)
    + reason = "RTT";
    + else if (reg & AT91_SHDW_RTCWK)
    + reason = "RTC";
    +
    + pr_info("AT91: Wake-Up source: %s\n", reason);
    +}
    +
    +static void at91_poweroff(void)
    +{
    + writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR);
    +}
    +
    +const enum wakeup_type at91_poweroff_get_wakeup_mode(struct device_node *np)
    +{
    + const char *pm;
    + int err, i;
    +
    + err = of_property_read_string(np, "atmel,wakeup-mode", &pm);
    + if (err < 0)
    + return AT91_SHDW_WKMODE0_ANYLEVEL;
    +
    + for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++)
    + if (!strcasecmp(pm, shdwc_wakeup_modes[i]))
    + return i;
    +
    + return -ENODEV;
    +}
    +
    +static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
    +{
    + struct device_node *np = pdev->dev.of_node;
    + enum wakeup_type wakeup_mode;
    + u32 mode = 0, tmp;
    +
    + wakeup_mode = at91_poweroff_get_wakeup_mode(np);
    + if (wakeup_mode < 0) {
    + dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n");
    + return;
    + }
    +
    + if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) {
    + if (tmp > AT91_SHDW_CPTWK0_MAX) {
    + dev_warn(&pdev->dev,
    + "shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n",
    + tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX);
    + tmp = AT91_SHDW_CPTWK0_MAX;
    + }
    + mode |= AT91_SHDW_CPTWK0_(tmp);
    + }
    +
    + if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
    + mode |= AT91_SHDW_RTCWKEN;
    +
    + if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
    + mode |= AT91_SHDW_RTTWKEN;
    +
    + writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR);
    +}
    +
    +static int at91_poweroff_probe(struct platform_device *pdev)
    +{
    + struct resource *res;
    +
    + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    + at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
    + if (IS_ERR(at91_shdwc_base)) {
    + dev_err(&pdev->dev, "Could not map reset controller address\n");
    + return PTR_ERR(at91_shdwc_base);
    + }
    +
    + at91_wakeup_status();
    +
    + if (pdev->dev.of_node)
    + at91_poweroff_dt_set_wakeup_mode(pdev);
    +
    + pm_power_off = at91_poweroff;
    +
    + return 0;
    +}
    +
    +static struct of_device_id at91_poweroff_of_match[] = {
    + { .compatible = "atmel,at91sam9260-shdwc", },
    + { .compatible = "atmel,at91sam9rl-shdwc", },
    + { .compatible = "atmel,at91sam9x5-shdwc", },
    + { /*sentinel*/ }
    +};
    +
    +static struct platform_driver at91_poweroff_driver = {
    + .probe = at91_poweroff_probe,
    + .driver = {
    + .name = "at91-poweroff",
    + .of_match_table = at91_poweroff_of_match,
    + },
    +};
    +module_platform_driver(at91_poweroff_driver);
    --
    2.0.1


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