clk: at91: Add sama5d2 suspend/resume

On sama5d2, VDD core maybe be cut while in suspend. This means registers
will be lost. Ensure they are saved and restored properly.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
index 07c8f701e51c6f3d032f3aaf1971a9dc1ae6b736..f0b7ae904ce2c991d8a5f998734a77235de194ee 100644 (file)
--- a/drivers/clk/at91/clk-generated.c
+++ b/drivers/clk/at91/clk-generated.c
@@ -266,6 +266,8 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock,
        if (ret) {
                kfree(gck);
                hw = ERR_PTR(ret);
+       } else {
+               pmc_register_id(id);
        }
 
        return hw;

diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c
index dc29fd979d3fc33695e68fcf48fd4de599f2d44f..7701183692308e8870a669658e8c24b4d14700e4 100644 (file)
--- a/drivers/clk/at91/clk-peripheral.c
+++ b/drivers/clk/at91/clk-peripheral.c
@@ -367,8 +367,10 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,
        if (ret) {
                kfree(periph);
                hw = ERR_PTR(ret);
-       } else
+       } else {
                clk_sam9x5_peripheral_autodiv(periph);
+               pmc_register_id(id);
+       }
 
        return hw;
 }

diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index 526df5ba042ddfd11a2bbe6441bccc6c1eb81f8d..775af473fe115b28f9963ff9fb44202249ecfdd6 100644 (file)
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -13,12 +13,16 @@
 #include <linux/clk/at91_pmc.h>
 #include <linux/of.h>
 #include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/syscore_ops.h>
 
 #include <asm/proc-fns.h>
 
 #include "pmc.h"
 
+#define PMC_MAX_IDS 128
+
 int of_at91_get_clk_range(struct device_node *np, const char *propname,
                          struct clk_range *range)
 {
@@ -41,3 +45,128 @@ int of_at91_get_clk_range(struct device_node *np, const char *propname,
        return 0;
 }
 EXPORT_SYMBOL_GPL(of_at91_get_clk_range);
+
+#ifdef CONFIG_PM
+static struct regmap *pmcreg;
+
+static u8 registered_ids[PMC_MAX_IDS];
+
+static struct
+{
+       u32 scsr;
+       u32 pcsr0;
+       u32 uckr;
+       u32 mor;
+       u32 mcfr;
+       u32 pllar;
+       u32 mckr;
+       u32 usb;
+       u32 imr;
+       u32 pcsr1;
+       u32 pcr[PMC_MAX_IDS];
+       u32 audio_pll0;
+       u32 audio_pll1;
+} pmc_cache;
+
+void pmc_register_id(u8 id)
+{
+       int i;
+
+       for (i = 0; i < PMC_MAX_IDS; i++) {
+               if (registered_ids[i] == 0) {
+                       registered_ids[i] = id;
+                       break;
+               }
+               if (registered_ids[i] == id)
+                       break;
+       }
+}
+
+static int pmc_suspend(void)
+{
+       int i;
+
+       regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.scsr);
+       regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);
+       regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);
+       regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);
+       regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);
+       regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);
+       regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);
+       regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);
+       regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);
+       regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);
+
+       for (i = 0; registered_ids[i]; i++) {
+               regmap_write(pmcreg, AT91_PMC_PCR,
+                            (registered_ids[i] & AT91_PMC_PCR_PID_MASK));
+               regmap_read(pmcreg, AT91_PMC_PCR,
+                           &pmc_cache.pcr[registered_ids[i]]);
+       }
+
+       return 0;
+}
+
+static void pmc_resume(void)
+{
+       int i, ret = 0;
+       u32 tmp;
+
+       regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
+       if (pmc_cache.mckr != tmp)
+               pr_warn("MCKR was not configured properly by the firmware\n");
+       regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);
+       if (pmc_cache.pllar != tmp)
+               pr_warn("PLLAR was not configured properly by the firmware\n");
+
+       regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.scsr);
+       regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);
+       regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);
+       regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);
+       regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);
+       regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);
+       regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);
+       regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);
+
+       for (i = 0; registered_ids[i]; i++) {
+               regmap_write(pmcreg, AT91_PMC_PCR,
+                            pmc_cache.pcr[registered_ids[i]] |
+                            AT91_PMC_PCR_CMD);
+       }
+
+       if (pmc_cache.uckr & AT91_PMC_UPLLEN) {
+               ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp,
+                                              !(tmp & AT91_PMC_LOCKU),
+                                              10, 5000);
+               if (ret)
+                       pr_crit("USB PLL didn't lock when resuming\n");
+       }
+}
+
+static struct syscore_ops pmc_syscore_ops = {
+       .suspend = pmc_suspend,
+       .resume = pmc_resume,
+};
+
+static const struct of_device_id sama5d2_pmc_dt_ids[] = {
+       { .compatible = "atmel,sama5d2-pmc" },
+       { /* sentinel */ }
+};
+
+static int __init pmc_register_ops(void)
+{
+       struct device_node *np;
+
+       np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
+
+       pmcreg = syscon_node_to_regmap(np);
+       if (IS_ERR(pmcreg))
+               return PTR_ERR(pmcreg);
+
+       register_syscore_ops(&pmc_syscore_ops);
+
+       return 0;
+}
+/* This has to happen before arch_initcall because of the tcb_clksrc driver */
+postcore_initcall(pmc_register_ops);
+#endif

diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 5771fff0ee3fdf345422baa54903b1864027f2c3..858e8ef7e8dbc1d252a9dc7a6d91989a7e3d77f3 100644 (file)
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -29,4 +29,10 @@ struct clk_range {
 int of_at91_get_clk_range(struct device_node *np, const char *propname,
                          struct clk_range *range);
 
+#ifdef CONFIG_PM
+void pmc_register_id(u8 id);
+#else
+static inline void pmc_register_id(u8 id) {}
+#endif
+
 #endif /* __PMC_H_ */