[PATCH 12/18] power: reset: Add AT91 poweroff driver
Maxime Ripard
maxime.ripard at free-electrons.com
Thu Jul 3 07:14:54 PDT 2014
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 at 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 at 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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