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-rw-r--r--kernel/arch/arm/mach-at91/pm.c447
1 files changed, 447 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-at91/pm.c b/kernel/arch/arm/mach-at91/pm.c
new file mode 100644
index 000000000..5062699cb
--- /dev/null
+++ b/kernel/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();
+}