phy: phy-samsung-usb2: Change phy power on/power off sequence

The Exynos4412 USB 2.0 PHY hardware differs from the description provided
in the documentation. Some register bits have different function. This
patch fixes the defines of register bits and changes the way how phys are
powered on and off.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Tested-by: Daniel Drake <drake@endlessm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

3 files changed, 77 insertions, 40 deletions

diff --git a/drivers/phy/phy-exynos4x12-usb2.c b/drivers/phy/phy-exynos4x12-usb2.c
index d92a7cc5698a..63134d8bda08 100644
--- a/drivers/phy/phy-exynos4x12-usb2.c
+++ b/drivers/phy/phy-exynos4x12-usb2.c
@@ -86,13 +86,23 @@
 #define EXYNOS_4x12_URSTCON_OTG_HLINK           BIT(1)
 #define EXYNOS_4x12_URSTCON_OTG_PHYLINK         BIT(2)
 #define EXYNOS_4x12_URSTCON_HOST_PHY            BIT(3)
+/* The following bit defines are presented in the
+ * order taken from the Exynos4412 reference manual.
+ *
+ * During experiments with the hardware and debugging
+ * it was determined that the hardware behaves contrary
+ * to the manual.
+ *
+ * The following bit values were chaned accordingly to the
+ * results of real hardware experiments.
+ */
 #define EXYNOS_4x12_URSTCON_PHY1                BIT(4)
-#define EXYNOS_4x12_URSTCON_HSIC0               BIT(5)
-#define EXYNOS_4x12_URSTCON_HSIC1               BIT(6)
+#define EXYNOS_4x12_URSTCON_HSIC0               BIT(6)
+#define EXYNOS_4x12_URSTCON_HSIC1               BIT(5)
 #define EXYNOS_4x12_URSTCON_HOST_LINK_ALL       BIT(7)
-#define EXYNOS_4x12_URSTCON_HOST_LINK_P0        BIT(8)
+#define EXYNOS_4x12_URSTCON_HOST_LINK_P0        BIT(10)
 #define EXYNOS_4x12_URSTCON_HOST_LINK_P1        BIT(9)
-#define EXYNOS_4x12_URSTCON_HOST_LINK_P2        BIT(10)
+#define EXYNOS_4x12_URSTCON_HOST_LINK_P2        BIT(8)
 
 /* Isolation, configured in the power management unit */
 #define EXYNOS_4x12_USB_ISOL_OFFSET             0x704
@@ -188,6 +198,7 @@ static void exynos4x12_setup_clk(struct samsung_usb2_phy_instance *inst)
         clk = readl(drv->reg_phy + EXYNOS_4x12_UPHYCLK);
         clk &= ~EXYNOS_4x12_UPHYCLK_PHYFSEL_MASK;
         clk |= drv->ref_reg_val << EXYNOS_4x12_UPHYCLK_PHYFSEL_OFFSET;
+        clk |= EXYNOS_4x12_UPHYCLK_PHY1_COMMON_ON;
         writel(clk, drv->reg_phy + EXYNOS_4x12_UPHYCLK);
 }
 
@@ -198,27 +209,22 @@ static void exynos4x12_phy_pwr(struct samsung_usb2_phy_instance *inst, bool on)
         u32 phypwr = 0;
         u32 rst;
         u32 pwr;
-        u32 mode = 0;
-        u32 switch_mode = 0;
 
         switch (inst->cfg->id) {
         case EXYNOS4x12_DEVICE:
                 phypwr =        EXYNOS_4x12_UPHYPWR_PHY0;
                 rstbits =       EXYNOS_4x12_URSTCON_PHY0;
-                mode =          EXYNOS_4x12_MODE_SWITCH_DEVICE;
-                switch_mode =   1;
                 break;
         case EXYNOS4x12_HOST:
                 phypwr =        EXYNOS_4x12_UPHYPWR_PHY1;
-                rstbits =       EXYNOS_4x12_URSTCON_HOST_PHY;
-                mode =          EXYNOS_4x12_MODE_SWITCH_HOST;
-                switch_mode =   1;
+                rstbits =       EXYNOS_4x12_URSTCON_HOST_PHY |
+                                EXYNOS_4x12_URSTCON_PHY1 |
+                                EXYNOS_4x12_URSTCON_HOST_LINK_P0;
                 break;
         case EXYNOS4x12_HSIC0:
                 phypwr =        EXYNOS_4x12_UPHYPWR_HSIC0;
-                rstbits =       EXYNOS_4x12_URSTCON_HSIC1 |
-                                EXYNOS_4x12_URSTCON_HOST_LINK_P0 |
-                                EXYNOS_4x12_URSTCON_HOST_PHY;
+                rstbits =       EXYNOS_4x12_URSTCON_HSIC0 |
+                                EXYNOS_4x12_URSTCON_HOST_LINK_P1;
                 break;
         case EXYNOS4x12_HSIC1:
                 phypwr =        EXYNOS_4x12_UPHYPWR_HSIC1;
@@ -228,11 +234,6 @@ static void exynos4x12_phy_pwr(struct samsung_usb2_phy_instance *inst, bool on)
         };
 
         if (on) {
-                if (switch_mode)
-                        regmap_update_bits(drv->reg_sys,
-                                           EXYNOS_4x12_MODE_SWITCH_OFFSET,
-                                           EXYNOS_4x12_MODE_SWITCH_MASK, mode);
-
                 pwr = readl(drv->reg_phy + EXYNOS_4x12_UPHYPWR);
                 pwr &= ~phypwr;
                 writel(pwr, drv->reg_phy + EXYNOS_4x12_UPHYPWR);
@@ -253,41 +254,78 @@ static void exynos4x12_phy_pwr(struct samsung_usb2_phy_instance *inst, bool on)
         }
 }
 
-static int exynos4x12_power_on(struct samsung_usb2_phy_instance *inst)
+static void exynos4x12_power_on_int(struct samsung_usb2_phy_instance *inst)
 {
-        struct samsung_usb2_phy_driver *drv = inst->drv;
+        if (inst->int_cnt++ > 0)
+                return;
 
-        inst->enabled = 1;
         exynos4x12_setup_clk(inst);
-        exynos4x12_phy_pwr(inst, 1);
         exynos4x12_isol(inst, 0);
+        exynos4x12_phy_pwr(inst, 1);
+}
+
+static int exynos4x12_power_on(struct samsung_usb2_phy_instance *inst)
+{
+        struct samsung_usb2_phy_driver *drv = inst->drv;
+
+        if (inst->ext_cnt++ > 0)
+                return 0;
 
-        /* Power on the device, as it is necessary for HSIC to work */
-        if (inst->cfg->id == EXYNOS4x12_HSIC0) {
-                struct samsung_usb2_phy_instance *device =
-                                        &drv->instances[EXYNOS4x12_DEVICE];
-                exynos4x12_phy_pwr(device, 1);
-                exynos4x12_isol(device, 0);
+        if (inst->cfg->id == EXYNOS4x12_HOST) {
+                regmap_update_bits(drv->reg_sys, EXYNOS_4x12_MODE_SWITCH_OFFSET,
+                                                EXYNOS_4x12_MODE_SWITCH_MASK,
+                                                EXYNOS_4x12_MODE_SWITCH_HOST);
+                exynos4x12_power_on_int(&drv->instances[EXYNOS4x12_DEVICE]);
         }
 
+        if (inst->cfg->id == EXYNOS4x12_DEVICE)
+                regmap_update_bits(drv->reg_sys, EXYNOS_4x12_MODE_SWITCH_OFFSET,
+                                                EXYNOS_4x12_MODE_SWITCH_MASK,
+                                                EXYNOS_4x12_MODE_SWITCH_DEVICE);
+
+        if (inst->cfg->id == EXYNOS4x12_HSIC0 ||
+                inst->cfg->id == EXYNOS4x12_HSIC1) {
+                exynos4x12_power_on_int(&drv->instances[EXYNOS4x12_DEVICE]);
+                exynos4x12_power_on_int(&drv->instances[EXYNOS4x12_HOST]);
+        }
+
+        exynos4x12_power_on_int(inst);
+
         return 0;
 }
 
-static int exynos4x12_power_off(struct samsung_usb2_phy_instance *inst)
+static void exynos4x12_power_off_int(struct samsung_usb2_phy_instance *inst)
 {
-        struct samsung_usb2_phy_driver *drv = inst->drv;
-        struct samsung_usb2_phy_instance *device =
-                                        &drv->instances[EXYNOS4x12_DEVICE];
+        if (inst->int_cnt-- > 1)
+                return;
 
-        inst->enabled = 0;
         exynos4x12_isol(inst, 1);
         exynos4x12_phy_pwr(inst, 0);
+}
 
-        if (inst->cfg->id == EXYNOS4x12_HSIC0 && !device->enabled) {
-                exynos4x12_isol(device, 1);
-                exynos4x12_phy_pwr(device, 0);
+static int exynos4x12_power_off(struct samsung_usb2_phy_instance *inst)
+{
+        struct samsung_usb2_phy_driver *drv = inst->drv;
+
+        if (inst->ext_cnt-- > 1)
+                return 0;
+
+        if (inst->cfg->id == EXYNOS4x12_DEVICE)
+                regmap_update_bits(drv->reg_sys, EXYNOS_4x12_MODE_SWITCH_OFFSET,
+                                                EXYNOS_4x12_MODE_SWITCH_MASK,
+                                                EXYNOS_4x12_MODE_SWITCH_HOST);
+
+        if (inst->cfg->id == EXYNOS4x12_HOST)
+                exynos4x12_power_off_int(&drv->instances[EXYNOS4x12_DEVICE]);
+
+        if (inst->cfg->id == EXYNOS4x12_HSIC0 ||
+                inst->cfg->id == EXYNOS4x12_HSIC1) {
+                exynos4x12_power_off_int(&drv->instances[EXYNOS4x12_DEVICE]);
+                exynos4x12_power_off_int(&drv->instances[EXYNOS4x12_HOST]);
         }
 
+        exynos4x12_power_off_int(inst);
+
         return 0;
 }
 
diff --git a/drivers/phy/phy-exynos5250-usb2.c b/drivers/phy/phy-exynos5250-usb2.c
index 94179afda951..1c139aa0d074 100644
--- a/drivers/phy/phy-exynos5250-usb2.c
+++ b/drivers/phy/phy-exynos5250-usb2.c
@@ -318,7 +318,6 @@ static int exynos5250_power_on(struct samsung_usb2_phy_instance *inst)
 
                 break;
         }
-        inst->enabled = 1;
         exynos5250_isol(inst, 0);
 
         return 0;
@@ -331,7 +330,6 @@ static int exynos5250_power_off(struct samsung_usb2_phy_instance *inst)
         u32 otg;
         u32 hsic;
 
-        inst->enabled = 0;
         exynos5250_isol(inst, 1);
 
         switch (inst->cfg->id) {
diff --git a/drivers/phy/phy-samsung-usb2.h b/drivers/phy/phy-samsung-usb2.h
index 45b3170652bd..918847843a95 100644
--- a/drivers/phy/phy-samsung-usb2.h
+++ b/drivers/phy/phy-samsung-usb2.h
@@ -29,7 +29,8 @@ struct samsung_usb2_phy_instance {
         const struct samsung_usb2_common_phy *cfg;
         struct phy *phy;
         struct samsung_usb2_phy_driver *drv;
-        bool enabled;
+        int int_cnt;
+        int ext_cnt;
 };
 
 struct samsung_usb2_phy_driver {