1 files changed, 173 insertions, 85 deletions

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 5e34fb143309..5062699cbb12 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -29,19 +29,26 @@
 #include <linux/atomic.h>
 #include <asm/mach/time.h>
 #include <asm/mach/irq.h>
-
-#include <mach/cpu.h>
-#include <mach/hardware.h>
+#include <asm/fncpy.h>
+#include <asm/cacheflush.h>
 
 #include "generic.h"
 #include "pm.h"
 
+/*
+ * FIXME: this is needed to communicate between the pinctrl driver and
+ * the PM implementation in the machine. Possibly part of the PM
+ * implementation should be moved down into the pinctrl driver and get
+ * called as part of the generic suspend/resume path.
+ */
+extern void at91_pinctrl_gpio_suspend(void);
+extern void at91_pinctrl_gpio_resume(void);
+
 static struct {
 	unsigned long uhp_udp_mask;
 	int memctrl;
 } at91_pm_data;
 
-static void (*at91_pm_standby)(void);
 void __iomem *at91_ramc_base[2];
 
 static int at91_pm_valid_state(suspend_state_t state)
@@ -119,76 +126,67 @@ int at91_suspend_entering_slow_clock(void)
 }
 EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
 
-
-static void (*slow_clock)(void __iomem *pmc, void __iomem *ramc0,
+static void (*at91_suspend_sram_fn)(void __iomem *pmc, void __iomem *ramc0,
 			  void __iomem *ramc1, int memctrl);
 
-#ifdef CONFIG_AT91_SLOW_CLOCK
-extern void at91_slow_clock(void __iomem *pmc, void __iomem *ramc0,
+extern void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *ramc0,
 			    void __iomem *ramc1, int memctrl);
-extern u32 at91_slow_clock_sz;
-#endif
+extern u32 at91_pm_suspend_in_sram_sz;
+
+static void at91_pm_suspend(suspend_state_t state)
+{
+	unsigned int pm_data = at91_pm_data.memctrl;
+
+	pm_data |= (state == PM_SUSPEND_MEM) ?
+				AT91_PM_MODE(AT91_PM_SLOW_CLOCK) : 0;
+
+	flush_cache_all();
+	outer_disable();
+
+	at91_suspend_sram_fn(at91_pmc_base, at91_ramc_base[0],
+				at91_ramc_base[1], pm_data);
+
+	outer_resume();
+}
 
 static int at91_pm_enter(suspend_state_t state)
 {
 	at91_pinctrl_gpio_suspend();
 
 	switch (state) {
+	/*
+	 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
+	 * drivers must suspend more deeply, the master clock switches
+	 * to the clk32k and turns off the main oscillator
+	 */
+	case PM_SUSPEND_MEM:
 		/*
-		 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
-		 * drivers must suspend more deeply:  only the master clock
-		 * controller may be using the main oscillator.
+		 * Ensure that clocks are in a valid state.
 		 */
-		case PM_SUSPEND_MEM:
-			/*
-			 * Ensure that clocks are in a valid state.
-			 */
-			if (!at91_pm_verify_clocks())
-				goto error;
-
-			/*
-			 * Enter slow clock mode by switching over to clk32k and
-			 * turning off the main oscillator; reverse on wakeup.
-			 */
-			if (slow_clock) {
-#ifdef CONFIG_AT91_SLOW_CLOCK
-				/* copy slow_clock handler to SRAM, and call it */
-				memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
-#endif
-				slow_clock(at91_pmc_base, at91_ramc_base[0],
-					   at91_ramc_base[1],
-					   at91_pm_data.memctrl);
-				break;
-			} else {
-				pr_info("AT91: PM - no slow clock mode enabled ...\n");
-				/* FALLTHROUGH leaving master clock alone */
-			}
+		if (!at91_pm_verify_clocks())
+			goto error;
 
-		/*
-		 * STANDBY mode has *all* drivers suspended; ignores irqs not
-		 * marked as 'wakeup' event sources; and reduces DRAM power.
-		 * But otherwise it's identical to PM_SUSPEND_ON:  cpu idle, and
-		 * nothing fancy done with main or cpu clocks.
-		 */
-		case PM_SUSPEND_STANDBY:
-			/*
-			 * NOTE: the Wait-for-Interrupt instruction needs to be
-			 * in icache so no SDRAM accesses are needed until the
-			 * wakeup IRQ occurs and self-refresh is terminated.
-			 * For ARM 926 based chips, this requirement is weaker
-			 * as at91sam9 can access a RAM in self-refresh mode.
-			 */
-			if (at91_pm_standby)
-				at91_pm_standby();
-			break;
+		at91_pm_suspend(state);
 
-		case PM_SUSPEND_ON:
-			cpu_do_idle();
-			break;
+		break;
 
-		default:
-			pr_debug("AT91: PM - bogus suspend state %d\n", state);
-			goto error;
+	/*
+	 * STANDBY mode has *all* drivers suspended; ignores irqs not
+	 * marked as 'wakeup' event sources; and reduces DRAM power.
+	 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
+	 * nothing fancy done with main or cpu clocks.
+	 */
+	case PM_SUSPEND_STANDBY:
+		at91_pm_suspend(state);
+		break;
+
+	case PM_SUSPEND_ON:
+		cpu_do_idle();
+		break;
+
+	default:
+		pr_debug("AT91: PM - bogus suspend state %d\n", state);
+		goto error;
 	}
 
 error:
@@ -218,12 +216,99 @@ static struct platform_device at91_cpuidle_device = {
 	.name = "cpuidle-at91",
 };
 
-void at91_pm_set_standby(void (*at91_standby)(void))
+static void at91_pm_set_standby(void (*at91_standby)(void))
 {
-	if (at91_standby) {
+	if (at91_standby)
 		at91_cpuidle_device.dev.platform_data = at91_standby;
-		at91_pm_standby = at91_standby;
+}
+
+/*
+ * The AT91RM9200 goes into self-refresh mode with this command, and will
+ * terminate self-refresh automatically on the next SDRAM access.
+ *
+ * Self-refresh mode is exited as soon as a memory access is made, but we don't
+ * know for sure when that happens. However, we need to restore the low-power
+ * mode if it was enabled before going idle. Restoring low-power mode while
+ * still in self-refresh is "not recommended", but seems to work.
+ */
+static void at91rm9200_standby(void)
+{
+	u32 lpr = at91_ramc_read(0, AT91RM9200_SDRAMC_LPR);
+
+	asm volatile(
+		"b    1f\n\t"
+		".align    5\n\t"
+		"1:  mcr    p15, 0, %0, c7, c10, 4\n\t"
+		"    str    %0, [%1, %2]\n\t"
+		"    str    %3, [%1, %4]\n\t"
+		"    mcr    p15, 0, %0, c7, c0, 4\n\t"
+		"    str    %5, [%1, %2]"
+		:
+		: "r" (0), "r" (at91_ramc_base[0]), "r" (AT91RM9200_SDRAMC_LPR),
+		  "r" (1), "r" (AT91RM9200_SDRAMC_SRR),
+		  "r" (lpr));
+}
+
+/* We manage both DDRAM/SDRAM controllers, we need more than one value to
+ * remember.
+ */
+static void at91_ddr_standby(void)
+{
+	/* Those two values allow us to delay self-refresh activation
+	 * to the maximum. */
+	u32 lpr0, lpr1 = 0;
+	u32 saved_lpr0, saved_lpr1 = 0;
+
+	if (at91_ramc_base[1]) {
+		saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR);
+		lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB;
+		lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
 	}
+
+	saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR);
+	lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB;
+	lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH;
+
+	/* self-refresh mode now */
+	at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0);
+	if (at91_ramc_base[1])
+		at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1);
+
+	cpu_do_idle();
+
+	at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0);
+	if (at91_ramc_base[1])
+		at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
+}
+
+/* We manage both DDRAM/SDRAM controllers, we need more than one value to
+ * remember.
+ */
+static void at91sam9_sdram_standby(void)
+{
+	u32 lpr0, lpr1 = 0;
+	u32 saved_lpr0, saved_lpr1 = 0;
+
+	if (at91_ramc_base[1]) {
+		saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
+		lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
+		lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
+	}
+
+	saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
+	lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
+	lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
+
+	/* self-refresh mode now */
+	at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
+	if (at91_ramc_base[1])
+		at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
+
+	cpu_do_idle();
+
+	at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
+	if (at91_ramc_base[1])
+		at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
 }
 
 static const struct of_device_id ramc_ids[] __initconst = {
@@ -263,60 +348,63 @@ static __init void at91_dt_ramc(void)
 	at91_pm_set_standby(standby);
 }
 
-#ifdef CONFIG_AT91_SLOW_CLOCK
 static void __init at91_pm_sram_init(void)
 {
 	struct gen_pool *sram_pool;
 	phys_addr_t sram_pbase;
 	unsigned long sram_base;
 	struct device_node *node;
-	struct platform_device *pdev;
+	struct platform_device *pdev = NULL;
 
-	node = of_find_compatible_node(NULL, NULL, "mmio-sram");
-	if (!node) {
-		pr_warn("%s: failed to find sram node!\n", __func__);
-		return;
+	for_each_compatible_node(node, NULL, "mmio-sram") {
+		pdev = of_find_device_by_node(node);
+		if (pdev) {
+			of_node_put(node);
+			break;
+		}
 	}
 
-	pdev = of_find_device_by_node(node);
 	if (!pdev) {
 		pr_warn("%s: failed to find sram device!\n", __func__);
-		goto put_node;
+		return;
 	}
 
 	sram_pool = dev_get_gen_pool(&pdev->dev);
 	if (!sram_pool) {
 		pr_warn("%s: sram pool unavailable!\n", __func__);
-		goto put_node;
+		return;
 	}
 
-	sram_base = gen_pool_alloc(sram_pool, at91_slow_clock_sz);
+	sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
 	if (!sram_base) {
-		pr_warn("%s: unable to alloc ocram!\n", __func__);
-		goto put_node;
+		pr_warn("%s: unable to alloc sram!\n", __func__);
+		return;
 	}
 
 	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
-	slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz, false);
+	at91_suspend_sram_fn = __arm_ioremap_exec(sram_pbase,
+					at91_pm_suspend_in_sram_sz, false);
+	if (!at91_suspend_sram_fn) {
+		pr_warn("SRAM: Could not map\n");
+		return;
+	}
 
-put_node:
-	of_node_put(node);
+	/* Copy the pm suspend handler to SRAM */
+	at91_suspend_sram_fn = fncpy(at91_suspend_sram_fn,
+			&at91_pm_suspend_in_sram, at91_pm_suspend_in_sram_sz);
 }
-#endif
-
 
 static void __init at91_pm_init(void)
 {
-#ifdef CONFIG_AT91_SLOW_CLOCK
 	at91_pm_sram_init();
-#endif
-
-	pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
 
 	if (at91_cpuidle_device.dev.platform_data)
 		platform_device_register(&at91_cpuidle_device);
 
-	suspend_set_ops(&at91_pm_ops);
+	if (at91_suspend_sram_fn)
+		suspend_set_ops(&at91_pm_ops);
+	else
+		pr_info("AT91: PM not supported, due to no SRAM allocated\n");
 }
 
 void __init at91rm9200_pm_init(void)