Initial import

1 files changed, 447 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
new file mode 100644
index 000000000..5062699cb
--- /dev/null
+++ b/arch/arm/mach-at91/pm.c
@@ -0,0 +1,447 @@
+/*
+ * arch/arm/mach-at91/pm.c
+ * AT91 Power Management
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/gpio.h>
+#include <linux/suspend.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/genalloc.h>
+#include <linux/interrupt.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/clk/at91_pmc.h>
+
+#include <asm/irq.h>
+#include <linux/atomic.h>
+#include <asm/mach/time.h>
+#include <asm/mach/irq.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;
+
+void __iomem *at91_ramc_base[2];
+
+static int at91_pm_valid_state(suspend_state_t state)
+{
+	switch (state) {
+		case PM_SUSPEND_ON:
+		case PM_SUSPEND_STANDBY:
+		case PM_SUSPEND_MEM:
+			return 1;
+
+		default:
+			return 0;
+	}
+}
+
+
+static suspend_state_t target_state;
+
+/*
+ * Called after processes are frozen, but before we shutdown devices.
+ */
+static int at91_pm_begin(suspend_state_t state)
+{
+	target_state = state;
+	return 0;
+}
+
+/*
+ * Verify that all the clocks are correct before entering
+ * slow-clock mode.
+ */
+static int at91_pm_verify_clocks(void)
+{
+	unsigned long scsr;
+	int i;
+
+	scsr = at91_pmc_read(AT91_PMC_SCSR);
+
+	/* USB must not be using PLLB */
+	if ((scsr & at91_pm_data.uhp_udp_mask) != 0) {
+		pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
+		return 0;
+	}
+
+	/* PCK0..PCK3 must be disabled, or configured to use clk32k */
+	for (i = 0; i < 4; i++) {
+		u32 css;
+
+		if ((scsr & (AT91_PMC_PCK0 << i)) == 0)
+			continue;
+
+		css = at91_pmc_read(AT91_PMC_PCKR(i)) & AT91_PMC_CSS;
+		if (css != AT91_PMC_CSS_SLOW) {
+			pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i, css);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/*
+ * Call this from platform driver suspend() to see how deeply to suspend.
+ * For example, some controllers (like OHCI) need one of the PLL clocks
+ * in order to act as a wakeup source, and those are not available when
+ * going into slow clock mode.
+ *
+ * REVISIT: generalize as clk_will_be_available(clk)?  Other platforms have
+ * the very same problem (but not using at91 main_clk), and it'd be better
+ * to add one generic API rather than lots of platform-specific ones.
+ */
+int at91_suspend_entering_slow_clock(void)
+{
+	return (target_state == PM_SUSPEND_MEM);
+}
+EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
+
+static void (*at91_suspend_sram_fn)(void __iomem *pmc, void __iomem *ramc0,
+			  void __iomem *ramc1, int memctrl);
+
+extern void at91_pm_suspend_in_sram(void __iomem *pmc, void __iomem *ramc0,
+			    void __iomem *ramc1, int memctrl);
+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:
+		/*
+		 * Ensure that clocks are in a valid state.
+		 */
+		if (!at91_pm_verify_clocks())
+			goto error;
+
+		at91_pm_suspend(state);
+
+		break;
+
+	/*
+	 * 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:
+	target_state = PM_SUSPEND_ON;
+
+	at91_pinctrl_gpio_resume();
+	return 0;
+}
+
+/*
+ * Called right prior to thawing processes.
+ */
+static void at91_pm_end(void)
+{
+	target_state = PM_SUSPEND_ON;
+}
+
+
+static const struct platform_suspend_ops at91_pm_ops = {
+	.valid	= at91_pm_valid_state,
+	.begin	= at91_pm_begin,
+	.enter	= at91_pm_enter,
+	.end	= at91_pm_end,
+};
+
+static struct platform_device at91_cpuidle_device = {
+	.name = "cpuidle-at91",
+};
+
+static void at91_pm_set_standby(void (*at91_standby)(void))
+{
+	if (at91_standby)
+		at91_cpuidle_device.dev.platform_data = 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 = {
+	{ .compatible = "atmel,at91rm9200-sdramc", .data = at91rm9200_standby },
+	{ .compatible = "atmel,at91sam9260-sdramc", .data = at91sam9_sdram_standby },
+	{ .compatible = "atmel,at91sam9g45-ddramc", .data = at91_ddr_standby },
+	{ .compatible = "atmel,sama5d3-ddramc", .data = at91_ddr_standby },
+	{ /*sentinel*/ }
+};
+
+static __init void at91_dt_ramc(void)
+{
+	struct device_node *np;
+	const struct of_device_id *of_id;
+	int idx = 0;
+	const void *standby = NULL;
+
+	for_each_matching_node_and_match(np, ramc_ids, &of_id) {
+		at91_ramc_base[idx] = of_iomap(np, 0);
+		if (!at91_ramc_base[idx])
+			panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx);
+
+		if (!standby)
+			standby = of_id->data;
+
+		idx++;
+	}
+
+	if (!idx)
+		panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
+
+	if (!standby) {
+		pr_warn("ramc no standby function available\n");
+		return;
+	}
+
+	at91_pm_set_standby(standby);
+}
+
+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 = NULL;
+
+	for_each_compatible_node(node, NULL, "mmio-sram") {
+		pdev = of_find_device_by_node(node);
+		if (pdev) {
+			of_node_put(node);
+			break;
+		}
+	}
+
+	if (!pdev) {
+		pr_warn("%s: failed to find sram device!\n", __func__);
+		return;
+	}
+
+	sram_pool = dev_get_gen_pool(&pdev->dev);
+	if (!sram_pool) {
+		pr_warn("%s: sram pool unavailable!\n", __func__);
+		return;
+	}
+
+	sram_base = gen_pool_alloc(sram_pool, at91_pm_suspend_in_sram_sz);
+	if (!sram_base) {
+		pr_warn("%s: unable to alloc sram!\n", __func__);
+		return;
+	}
+
+	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
+	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;
+	}
+
+	/* 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);
+}
+
+static void __init at91_pm_init(void)
+{
+	at91_pm_sram_init();
+
+	if (at91_cpuidle_device.dev.platform_data)
+		platform_device_register(&at91_cpuidle_device);
+
+	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)
+{
+	at91_dt_ramc();
+
+	/*
+	 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
+	 */
+	at91_ramc_write(0, AT91RM9200_SDRAMC_LPR, 0);
+
+	at91_pm_data.uhp_udp_mask = AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP;
+	at91_pm_data.memctrl = AT91_MEMCTRL_MC;
+
+	at91_pm_init();
+}
+
+void __init at91sam9260_pm_init(void)
+{
+	at91_dt_ramc();
+	at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;
+	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
+	return at91_pm_init();
+}
+
+void __init at91sam9g45_pm_init(void)
+{
+	at91_dt_ramc();
+	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP;
+	at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
+	return at91_pm_init();
+}
+
+void __init at91sam9x5_pm_init(void)
+{
+	at91_dt_ramc();
+	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
+	at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
+	return at91_pm_init();
+}