[ARM] pxa: better MFP low power state support for pxa25x/pxa27x

When configured as a specific low power state: MFP_LPM_DRIVE_LOW,
MFP_LPM_DRIVE_HIGH, the corresponding GPDR register bit during
low power mode shall be re-configured as output (if they are not
configured so), thus the PGSRx bits can output.

Create an additional low power values GPDR registers, and properly
save/restore the GAFR + GPDR registers when doing suspend/resume.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 149 insertions, 73 deletions

diff --git a/arch/arm/mach-pxa/mfp-pxa2xx.c b/arch/arm/mach-pxa/mfp-pxa2xx.c
index 925575f10acf..3ee1f39062e9 100644
--- a/arch/arm/mach-pxa/mfp-pxa2xx.c
+++ b/arch/arm/mach-pxa/mfp-pxa2xx.c
@@ -25,7 +25,12 @@
 
 #include "generic.h"
 
-#define PGSR(x)         __REG2(0x40F00020, ((x) & 0x60) >> 3)
+#define gpio_to_bank(gpio)      ((gpio) >> 5)
+
+#define PGSR(x)         __REG2(0x40F00020, (x) << 2)
+#define __GAFR(u, x)    __REG2((u) ? 0x40E00058 : 0x40E00054, (x) << 3)
+#define GAFR_L(x)       __GAFR(0, x)
+#define GAFR_U(x)       __GAFR(1, x)
 
 #define PWER_WE35       (1 << 24)
 
@@ -38,49 +43,59 @@ struct gpio_desc {
 };
 
 static struct gpio_desc gpio_desc[MFP_PIN_GPIO127 + 1];
+static int gpio_nr;
 
-static int __mfp_config_lpm(unsigned gpio, unsigned long lpm)
-{
-        unsigned mask = GPIO_bit(gpio);
-
-        /* low power state */
-        switch (lpm) {
-        case MFP_LPM_DRIVE_HIGH:
-                PGSR(gpio) |= mask;
-                break;
-        case MFP_LPM_DRIVE_LOW:
-                PGSR(gpio) &= ~mask;
-                break;
-        case MFP_LPM_INPUT:
-                break;
-        default:
-                pr_warning("%s: invalid low power state for GPIO%d\n",
-                                __func__, gpio);
-                return -EINVAL;
-        }
-        return 0;
-}
+static unsigned long gpdr_lpm[4];
 
 static int __mfp_config_gpio(unsigned gpio, unsigned long c)
 {
         unsigned long gafr, mask = GPIO_bit(gpio);
-        int fn;
+        int bank = gpio_to_bank(gpio);
+        int uorl = !!(gpio & 0x10); /* GAFRx_U or GAFRx_L ? */
+        int shft = (gpio & 0xf) << 1;
+        int fn = MFP_AF(c);
+        int dir = c & MFP_DIR_OUT;
 
-        fn = MFP_AF(c);
         if (fn > 3)
                 return -EINVAL;
 
-        /* alternate function and direction */
-        gafr = GAFR(gpio) & ~(0x3 << ((gpio & 0xf) * 2));
-        GAFR(gpio) = gafr |  (fn  << ((gpio & 0xf) * 2));
+        /* alternate function and direction at run-time */
+        gafr = (uorl == 0) ? GAFR_L(bank) : GAFR_U(bank);
+        gafr = (gafr & ~(0x3 << shft)) | (fn << shft);
 
-        if (c & MFP_DIR_OUT)
+        if (uorl == 0)
+                GAFR_L(bank) = gafr;
+        else
+                GAFR_U(bank) = gafr;
+
+        if (dir == MFP_DIR_OUT)
                 GPDR(gpio) |= mask;
         else
                 GPDR(gpio) &= ~mask;
 
-        if (__mfp_config_lpm(gpio, c & MFP_LPM_STATE_MASK))
-                return -EINVAL;
+        /* alternate function and direction at low power mode */
+        switch (c & MFP_LPM_STATE_MASK) {
+        case MFP_LPM_DRIVE_HIGH:
+                PGSR(bank) |= mask;
+                dir = MFP_DIR_OUT;
+                break;
+        case MFP_LPM_DRIVE_LOW:
+                PGSR(bank) &= ~mask;
+                dir = MFP_DIR_OUT;
+                break;
+        case MFP_LPM_DEFAULT:
+                break;
+        default:
+                /* warning and fall through, treat as MFP_LPM_DEFAULT */
+                pr_warning("%s: GPIO%d: unsupported low power mode\n",
+                                __func__, gpio);
+                break;
+        }
+
+        if (dir == MFP_DIR_OUT)
+                gpdr_lpm[bank] |= mask;
+        else
+                gpdr_lpm[bank] &= ~mask;
 
         /* give early warning if MFP_LPM_CAN_WAKEUP is set on the
          * configurations of those pins not able to wakeup
@@ -91,7 +106,7 @@ static int __mfp_config_gpio(unsigned gpio, unsigned long c)
                 return -EINVAL;
         }
 
-        if ((c & MFP_LPM_CAN_WAKEUP) && (c & MFP_DIR_OUT)) {
+        if ((c & MFP_LPM_CAN_WAKEUP) && (dir == MFP_DIR_OUT)) {
                 pr_warning("%s: output GPIO%d unable to wakeup\n",
                                 __func__, gpio);
                 return -EINVAL;
@@ -135,7 +150,7 @@ void pxa2xx_mfp_config(unsigned long *mfp_cfgs, int num)
 
 void pxa2xx_mfp_set_lpm(int mfp, unsigned long lpm)
 {
-        unsigned long flags;
+        unsigned long flags, c;
         int gpio;
 
         gpio = __mfp_validate(mfp);
@@ -143,7 +158,11 @@ void pxa2xx_mfp_set_lpm(int mfp, unsigned long lpm)
                 return;
 
         local_irq_save(flags);
-        __mfp_config_lpm(gpio, lpm);
+
+        c = gpio_desc[gpio].config;
+        c = (c & ~MFP_LPM_STATE_MASK) | lpm;
+        __mfp_config_gpio(gpio, c);
+
         local_irq_restore(flags);
 }
 
@@ -187,23 +206,22 @@ int gpio_set_wake(unsigned int gpio, unsigned int on)
 }
 
 #ifdef CONFIG_PXA25x
-static int __init pxa25x_mfp_init(void)
+static void __init pxa25x_mfp_init(void)
 {
         int i;
 
-        if (cpu_is_pxa25x()) {
-                for (i = 0; i <= 84; i++)
-                        gpio_desc[i].valid = 1;
+        for (i = 0; i <= 84; i++)
+                gpio_desc[i].valid = 1;
 
-                for (i = 0; i <= 15; i++) {
-                        gpio_desc[i].can_wakeup = 1;
-                        gpio_desc[i].mask = GPIO_bit(i);
-                }
+        for (i = 0; i <= 15; i++) {
+                gpio_desc[i].can_wakeup = 1;
+                gpio_desc[i].mask = GPIO_bit(i);
         }
 
-        return 0;
+        gpio_nr = 85;
 }
-postcore_initcall(pxa25x_mfp_init);
+#else
+static inline void pxa25x_mfp_init(void) {}
 #endif /* CONFIG_PXA25x */
 
 #ifdef CONFIG_PXA27x
@@ -233,45 +251,103 @@ int keypad_set_wake(unsigned int on)
         return 0;
 }
 
-static int __init pxa27x_mfp_init(void)
+static void __init pxa27x_mfp_init(void)
 {
         int i, gpio;
 
-        if (cpu_is_pxa27x()) {
-                for (i = 0; i <= 120; i++) {
-                        /* skip GPIO2, 5, 6, 7, 8, they are not
-                         * valid pins allow configuration
-                         */
-                        if (i == 2 || i == 5 || i == 6 ||
-                            i == 7 || i == 8)
-                                continue;
+        for (i = 0; i <= 120; i++) {
+                /* skip GPIO2, 5, 6, 7, 8, they are not
+                 * valid pins allow configuration
+                 */
+                if (i == 2 || i == 5 || i == 6 || i == 7 || i == 8)
+                        continue;
 
-                        gpio_desc[i].valid = 1;
-                }
+                gpio_desc[i].valid = 1;
+        }
 
-                /* Keypad GPIOs */
-                for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {
-                        gpio = pxa27x_pkwr_gpio[i];
-                        gpio_desc[gpio].can_wakeup = 1;
-                        gpio_desc[gpio].keypad_gpio = 1;
-                        gpio_desc[gpio].mask = 1 << i;
-                }
+        /* Keypad GPIOs */
+        for (i = 0; i < ARRAY_SIZE(pxa27x_pkwr_gpio); i++) {
+                gpio = pxa27x_pkwr_gpio[i];
+                gpio_desc[gpio].can_wakeup = 1;
+                gpio_desc[gpio].keypad_gpio = 1;
+                gpio_desc[gpio].mask = 1 << i;
+        }
 
-                /* Overwrite GPIO13 as a PWER wakeup source */
-                for (i = 0; i <= 15; i++) {
-                        /* skip GPIO2, 5, 6, 7, 8 */
-                        if (GPIO_bit(i) & 0x1e4)
-                                continue;
+        /* Overwrite GPIO13 as a PWER wakeup source */
+        for (i = 0; i <= 15; i++) {
+                /* skip GPIO2, 5, 6, 7, 8 */
+                if (GPIO_bit(i) & 0x1e4)
+                        continue;
 
-                        gpio_desc[i].can_wakeup = 1;
-                        gpio_desc[i].mask = GPIO_bit(i);
-                }
+                gpio_desc[i].can_wakeup = 1;
+                gpio_desc[i].mask = GPIO_bit(i);
+        }
+
+        gpio_desc[35].can_wakeup = 1;
+        gpio_desc[35].mask = PWER_WE35;
+
+        gpio_nr = 121;
+}
+#else
+static inline void pxa27x_mfp_init(void) {}
+#endif /* CONFIG_PXA27x */
+
+#ifdef CONFIG_PM
+static unsigned long saved_gafr[2][4];
+static unsigned long saved_gpdr[4];
+
+static int pxa2xx_mfp_suspend(struct sys_device *d, pm_message_t state)
+{
+        int i;
+
+        for (i = 0; i <= gpio_to_bank(gpio_nr); i++) {
 
-                gpio_desc[35].can_wakeup = 1;
-                gpio_desc[35].mask = PWER_WE35;
+                saved_gafr[0][i] = GAFR_L(i);
+                saved_gafr[1][i] = GAFR_U(i);
+                saved_gpdr[i] = GPDR(i * 32);
+
+                GPDR(i * 32) = gpdr_lpm[i];
         }
+        return 0;
+}
 
+static int pxa2xx_mfp_resume(struct sys_device *d)
+{
+        int i;
+
+        for (i = 0; i <= gpio_to_bank(gpio_nr); i++) {
+                GAFR_L(i) = saved_gafr[0][i];
+                GAFR_U(i) = saved_gafr[1][i];
+                GPDR(i * 32) = saved_gpdr[i];
+        }
+        PSSR = PSSR_RDH | PSSR_PH;
         return 0;
 }
-postcore_initcall(pxa27x_mfp_init);
-#endif /* CONFIG_PXA27x */
+#else
+#define pxa2xx_mfp_suspend      NULL
+#define pxa2xx_mfp_resume       NULL
+#endif
+
+struct sysdev_class pxa2xx_mfp_sysclass = {
+        .name           = "mfp",
+        .suspend        = pxa2xx_mfp_suspend,
+        .resume         = pxa2xx_mfp_resume,
+};
+
+static int __init pxa2xx_mfp_init(void)
+{
+        int i;
+
+        if (cpu_is_pxa25x())
+                pxa25x_mfp_init();
+
+        if (cpu_is_pxa27x())
+                pxa27x_mfp_init();
+
+        /* initialize gafr_run[], pgsr_lpm[] from existing values */
+        for (i = 0; i <= gpio_to_bank(gpio_nr); i++)
+                gpdr_lpm[i] = GPDR(i * 32);
+
+        return sysdev_class_register(&pxa2xx_mfp_sysclass);
+}
+postcore_initcall(pxa2xx_mfp_init);