power: reset: Add AT91 poweroff driver

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 remove 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>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 360bac75a3daff49751fbf021db5e3161c58c3fb..1f9d0c53fc140a6ec7e8ba80d7a4031dee8ca1c0 100644 (file)
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -14,6 +14,14 @@ 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"
+       depends on MACH_AT91
+       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"
        depends on MACH_AT91

diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 1599214b91d9960010507976a7372e456c4d998c..8bf941bac3da8010a61142d348e454d6b55d69fa 100644 (file)
--- 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 (file)
index 0000000..40bf42d
--- /dev/null
+++ b/drivers/power/reset/at91-poweroff.c
@@ -0,0 +1,156 @@
+/*
+ * Atmel AT91 SAM9 SoCs reset code
+ *
+ * Copyright (C) 2007 Atmel Corporation.
+ * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ * Copyright (C) 2014 Free Electrons
+ *
+ * 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);