ARM: at91: pm: Add sama5d2 backup mode
The sama5d2 has a mode were it is possible to cut power to the SoC while
keeping the RAM in self refresh.
Resuming from that mode needs support in the firmware/bootloader.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Wenyou Yang <wenyou.yang@atmel.com>
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 2cd27c8..d138d19 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -22,6 +22,7 @@
#include <asm/cacheflush.h>
#include <asm/fncpy.h>
#include <asm/system_misc.h>
+#include <asm/suspend.h>
#include "generic.h"
#include "pm.h"
@@ -58,6 +59,14 @@ static int at91_pm_valid_state(suspend_state_t state)
}
}
+static int canary = 0xA5A5A5A5;
+
+static struct at91_pm_bu {
+ int suspended;
+ unsigned long reserved;
+ phys_addr_t canary;
+ phys_addr_t resume;
+} *pm_bu;
static suspend_state_t target_state;
@@ -123,15 +132,39 @@ static void (*at91_suspend_sram_fn)(struct at91_pm_data *);
extern void at91_pm_suspend_in_sram(struct at91_pm_data *pm_data);
extern u32 at91_pm_suspend_in_sram_sz;
-static void at91_pm_suspend(suspend_state_t state)
+static int at91_suspend_finish(unsigned long val)
{
- pm_data.mode = (state == PM_SUSPEND_MEM) ? AT91_PM_SLOW_CLOCK : 0;
-
flush_cache_all();
outer_disable();
at91_suspend_sram_fn(&pm_data);
+ return 0;
+}
+
+static void at91_pm_suspend(suspend_state_t state)
+{
+ if (pm_data.deepest_state == AT91_PM_BACKUP)
+ if (state == PM_SUSPEND_MEM)
+ pm_data.mode = AT91_PM_BACKUP;
+ else
+ pm_data.mode = AT91_PM_SLOW_CLOCK;
+ else
+ pm_data.mode = (state == PM_SUSPEND_MEM) ? AT91_PM_SLOW_CLOCK : 0;
+
+ if (pm_data.mode == AT91_PM_BACKUP) {
+ pm_bu->suspended = 1;
+
+ cpu_suspend(0, at91_suspend_finish);
+
+ /* The SRAM is lost between suspend cycles */
+ at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
+ &at91_pm_suspend_in_sram,
+ at91_pm_suspend_in_sram_sz);
+ } else {
+ at91_suspend_finish(0);
+ }
+
outer_resume();
}
@@ -436,6 +469,70 @@ static void __init at91_pm_sram_init(void)
&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
}
+static void __init at91_pm_backup_init(void)
+{
+ struct gen_pool *sram_pool;
+ struct device_node *np;
+ struct platform_device *pdev = NULL;
+
+ pm_bu = NULL;
+
+ np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-shdwc");
+ if (!np) {
+ pr_warn("%s: failed to find shdwc!\n", __func__);
+ return;
+ }
+
+ pm_data.shdwc = of_iomap(np, 0);
+ of_node_put(np);
+
+ np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-sfrbu");
+ if (!np) {
+ pr_warn("%s: failed to find sfrbu!\n", __func__);
+ goto sfrbu_fail;
+ }
+
+ pm_data.sfrbu = of_iomap(np, 0);
+ of_node_put(np);
+ pm_bu = NULL;
+
+ np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
+ if (!np)
+ goto securam_fail;
+
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+ if (!pdev) {
+ pr_warn("%s: failed to find securam device!\n", __func__);
+ goto securam_fail;
+ }
+
+ sram_pool = gen_pool_get(&pdev->dev, NULL);
+ if (!sram_pool) {
+ pr_warn("%s: securam pool unavailable!\n", __func__);
+ goto securam_fail;
+ }
+
+ pm_bu = (void *)gen_pool_alloc(sram_pool, sizeof(struct at91_pm_bu));
+ if (!pm_bu) {
+ pr_warn("%s: unable to alloc securam!\n", __func__);
+ goto securam_fail;
+ }
+
+ pm_bu->suspended = 0;
+ pm_bu->canary = virt_to_phys(&canary);
+ pm_bu->resume = virt_to_phys(cpu_resume);
+
+ return;
+
+sfrbu_fail:
+ iounmap(pm_data.shdwc);
+ pm_data.shdwc = NULL;
+securam_fail:
+ iounmap(pm_data.sfrbu);
+ pm_data.sfrbu = NULL;
+}
+
struct pmc_info {
unsigned long uhp_udp_mask;
};
@@ -510,3 +607,9 @@ void __init sama5_pm_init(void)
at91_dt_ramc();
at91_pm_init(NULL);
}
+
+void __init sama5d2_pm_init(void)
+{
+ at91_pm_backup_init();
+ sama5_pm_init();
+}