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SubjectRe: [PATCH 12/18] power: reset: Add AT91 poweroff driver
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On Jul 3, 2014, at 10:14 PM, Maxime Ripard <maxime.ripard@free-electrons.com> wrote:

>
> 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>
> + *

As it’s mostly a copy of other people work you can not claim the copyright
> + * 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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