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path: root/drivers/power/reset/at91-sama5d2_shdwc.c
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Diffstat (limited to 'drivers/power/reset/at91-sama5d2_shdwc.c')
-rw-r--r--drivers/power/reset/at91-sama5d2_shdwc.c49
1 files changed, 48 insertions, 1 deletions
diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index 8a5ac9706c9c..90b0b5a70ce5 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -22,9 +22,12 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
+#include <soc/at91/at91sam9_ddrsdr.h>
+
#define SLOW_CLOCK_FREQ 32768
#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
@@ -75,6 +78,7 @@ struct shdwc {
*/
static struct shdwc *at91_shdwc;
static struct clk *sclk;
+static void __iomem *mpddrc_base;
static const unsigned long long sdwc_dbc_period[] = {
0, 3, 32, 512, 4096, 32768,
@@ -108,6 +112,29 @@ static void at91_poweroff(void)
at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
}
+static void at91_lpddr_poweroff(void)
+{
+ asm volatile(
+ /* Align to cache lines */
+ ".balign 32\n\t"
+
+ /* Ensure AT91_SHDW_CR is in the TLB by reading it */
+ " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+ /* Power down SDRAM0 */
+ " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
+ /* Shutdown CPU */
+ " str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
+
+ " b .\n\t"
+ :
+ : "r" (mpddrc_base),
+ "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
+ "r" (at91_shdwc->at91_shdwc_base),
+ "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW)
+ : "r0");
+}
+
static u32 at91_shdwc_debouncer_value(struct platform_device *pdev,
u32 in_period_us)
{
@@ -212,6 +239,8 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
{
struct resource *res;
const struct of_device_id *match;
+ struct device_node *np;
+ u32 ddr_type;
int ret;
if (!pdev->dev.of_node)
@@ -249,6 +278,23 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
pm_power_off = at91_poweroff;
+ np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
+ if (!np)
+ return 0;
+
+ mpddrc_base = of_iomap(np, 0);
+ of_node_put(np);
+
+ if (!mpddrc_base)
+ return 0;
+
+ ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
+ if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) ||
+ (ddr_type == AT91_DDRSDRC_MD_LPDDR3))
+ pm_power_off = at91_lpddr_poweroff;
+ else
+ iounmap(mpddrc_base);
+
return 0;
}
@@ -256,7 +302,8 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
{
struct shdwc *shdw = platform_get_drvdata(pdev);
- if (pm_power_off == at91_poweroff)
+ if (pm_power_off == at91_poweroff ||
+ pm_power_off == at91_lpddr_poweroff)
pm_power_off = NULL;
/* Reset values to disable wake-up features */