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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/power/reset/at91-poweroff.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/power/reset/at91-poweroff.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
new file mode 100644
index 000000000..9e74e131c
--- /dev/null
+++ b/drivers/power/reset/at91-poweroff.c
@@ -0,0 +1,239 @@
+/*
+ * 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/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#include <soc/at91/at91sam9_ddrsdr.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 struct shdwc {
+ struct clk *sclk;
+ void __iomem *shdwc_base;
+ void __iomem *mpddrc_base;
+} at91_shdwc;
+
+static void __init at91_wakeup_status(struct platform_device *pdev)
+{
+ const char *reason;
+ u32 reg = readl(at91_shdwc.shdwc_base + AT91_SHDW_SR);
+
+ /* Simple power-on, just bail out */
+ if (!reg)
+ return;
+
+ if (reg & AT91_SHDW_RTTWK)
+ reason = "RTT";
+ else if (reg & AT91_SHDW_RTCWK)
+ reason = "RTC";
+ else
+ reason = "unknown";
+
+ dev_info(&pdev->dev, "Wake-Up source: %s\n", reason);
+}
+
+static void at91_poweroff(void)
+{
+ asm volatile(
+ /* Align to cache lines */
+ ".balign 32\n\t"
+
+ /* Ensure AT91_SHDW_CR is in the TLB by reading it */
+ " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+ /* Power down SDRAM0 */
+ " tst %0, #0\n\t"
+ " beq 1f\n\t"
+ " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
+ /* Shutdown CPU */
+ "1: str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+ " b .\n\t"
+ :
+ : "r" (at91_shdwc.mpddrc_base),
+ "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
+ "r" (at91_shdwc.shdwc_base),
+ "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW)
+ : "r6");
+}
+
+static int at91_poweroff_get_wakeup_mode(struct device_node *np)
+{
+ const char *pm;
+ unsigned int i;
+ int err;
+
+ 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;
+ int 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.shdwc_base + AT91_SHDW_MR);
+}
+
+static int __init at91_poweroff_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct device_node *np;
+ u32 ddr_type;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ at91_shdwc.shdwc_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(at91_shdwc.shdwc_base))
+ return PTR_ERR(at91_shdwc.shdwc_base);
+
+ at91_shdwc.sclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(at91_shdwc.sclk))
+ return PTR_ERR(at91_shdwc.sclk);
+
+ ret = clk_prepare_enable(at91_shdwc.sclk);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not enable slow clock\n");
+ return ret;
+ }
+
+ at91_wakeup_status(pdev);
+
+ if (pdev->dev.of_node)
+ at91_poweroff_dt_set_wakeup_mode(pdev);
+
+ np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
+ if (np) {
+ at91_shdwc.mpddrc_base = of_iomap(np, 0);
+ of_node_put(np);
+
+ if (!at91_shdwc.mpddrc_base) {
+ ret = -ENOMEM;
+ goto clk_disable;
+ }
+
+ ddr_type = readl(at91_shdwc.mpddrc_base + AT91_DDRSDRC_MDR) &
+ AT91_DDRSDRC_MD;
+ if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
+ ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
+ iounmap(at91_shdwc.mpddrc_base);
+ at91_shdwc.mpddrc_base = NULL;
+ }
+ }
+
+ pm_power_off = at91_poweroff;
+
+ return 0;
+
+clk_disable:
+ clk_disable_unprepare(at91_shdwc.sclk);
+ return ret;
+}
+
+static int __exit at91_poweroff_remove(struct platform_device *pdev)
+{
+ if (pm_power_off == at91_poweroff)
+ pm_power_off = NULL;
+
+ if (at91_shdwc.mpddrc_base)
+ iounmap(at91_shdwc.mpddrc_base);
+
+ clk_disable_unprepare(at91_shdwc.sclk);
+
+ return 0;
+}
+
+static const struct of_device_id at91_poweroff_of_match[] = {
+ { .compatible = "atmel,at91sam9260-shdwc", },
+ { .compatible = "atmel,at91sam9rl-shdwc", },
+ { .compatible = "atmel,at91sam9x5-shdwc", },
+ { /*sentinel*/ }
+};
+MODULE_DEVICE_TABLE(of, at91_poweroff_of_match);
+
+static struct platform_driver at91_poweroff_driver = {
+ .remove = __exit_p(at91_poweroff_remove),
+ .driver = {
+ .name = "at91-poweroff",
+ .of_match_table = at91_poweroff_of_match,
+ },
+};
+module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
+
+MODULE_AUTHOR("Atmel Corporation");
+MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");
+MODULE_LICENSE("GPL v2");