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authorAlexandre Belloni <alexandre.belloni@free-electrons.com>2015-01-15 17:59:25 +0300
committerNicolas Ferre <nicolas.ferre@atmel.com>2015-01-16 20:07:24 +0300
commitd2e467905596760f1218e3382de24ab2c14d5baf (patch)
tree92ef5881b290075fc7189bfa5d3318b0bfb5af9d /arch/arm/mach-at91
parentf5598d346e36169f3eb4008c895300a39b100a0b (diff)
downloadlinux-d2e467905596760f1218e3382de24ab2c14d5baf.tar.xz
ARM: at91: pm: use the mmio-sram pool to access SRAM
Now that the SRAM is part of a genpool, use it to allocate memory to use for the slowclock implementation. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Diffstat (limited to 'arch/arm/mach-at91')
-rw-r--r--arch/arm/mach-at91/Kconfig1
-rw-r--r--arch/arm/mach-at91/pm.c46
2 files changed, 46 insertions, 1 deletions
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index cec0fb5d621a..b7dcef50db23 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -178,6 +178,7 @@ comment "AT91 Feature Selections"
config AT91_SLOW_CLOCK
bool "Suspend-to-RAM disables main oscillator"
+ select SRAM
depends on SUSPEND
help
Select this if you want Suspend-to-RAM to save the most power
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 79aa793d1f00..515791edcc60 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -14,10 +14,12 @@
#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/platform_device.h>
#include <linux/io.h>
#include <linux/clk/at91_pmc.h>
@@ -222,10 +224,52 @@ void at91_pm_set_standby(void (*at91_standby)(void))
}
}
+#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;
+
+ node = of_find_compatible_node(NULL, NULL, "mmio-sram");
+ if (!node) {
+ pr_warn("%s: failed to find sram node!\n", __func__);
+ return;
+ }
+
+ pdev = of_find_device_by_node(node);
+ if (!pdev) {
+ pr_warn("%s: failed to find sram device!\n", __func__);
+ goto put_node;
+ }
+
+ sram_pool = dev_get_gen_pool(&pdev->dev);
+ if (!sram_pool) {
+ pr_warn("%s: sram pool unavailable!\n", __func__);
+ goto put_node;
+ }
+
+ sram_base = gen_pool_alloc(sram_pool, at91_slow_clock_sz);
+ if (!sram_base) {
+ pr_warn("%s: unable to alloc ocram!\n", __func__);
+ goto put_node;
+ }
+
+ sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
+ slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz, false);
+
+put_node:
+ of_node_put(node);
+}
+#endif
+
+
static int __init at91_pm_init(void)
{
#ifdef CONFIG_AT91_SLOW_CLOCK
- slow_clock = (void *) (AT91_IO_VIRT_BASE - at91_slow_clock_sz);
+ at91_pm_sram_init();
#endif
pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));