3 files changed, 108 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/mpc52xx.h b/arch/powerpc/include/asm/mpc52xx.h
index b664ce79a172..1f41382eda38 100644
--- a/arch/powerpc/include/asm/mpc52xx.h
+++ b/arch/powerpc/include/asm/mpc52xx.h
@@ -271,6 +271,7 @@ struct mpc52xx_intr {
 /* mpc52xx_common.c */
 extern void mpc5200_setup_xlb_arbiter(void);
 extern void mpc52xx_declare_of_platform_devices(void);
+extern int mpc5200_psc_ac97_gpio_reset(int psc_number);
 extern void mpc52xx_map_common_devices(void);
 extern int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv);
 extern unsigned int mpc52xx_get_xtal_freq(struct device_node *node);
diff --git a/arch/powerpc/include/asm/mpc52xx_psc.h b/arch/powerpc/include/asm/mpc52xx_psc.h
index ecc4fc69ac13..2966df604221 100644
--- a/arch/powerpc/include/asm/mpc52xx_psc.h
+++ b/arch/powerpc/include/asm/mpc52xx_psc.h
@@ -131,6 +131,7 @@
 #define MPC52xx_PSC_SICR_SIM_FIR                (0x6 << 24)
 #define MPC52xx_PSC_SICR_SIM_CODEC_24           (0x7 << 24)
 #define MPC52xx_PSC_SICR_SIM_CODEC_32           (0xf << 24)
+#define MPC52xx_PSC_SICR_ACRB                   (0x8 << 24)
 #define MPC52xx_PSC_SICR_AWR                    (1 << 30)
 #define MPC52xx_PSC_SICR_GENCLK                 (1 << 23)
 #define MPC52xx_PSC_SICR_I2S                    (1 << 22)
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c
index a46bad0c2339..6e905314ad5d 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_common.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c
@@ -12,9 +12,11 @@
 
 #undef DEBUG
 
+#include <linux/gpio.h>
 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/of_platform.h>
+#include <linux/of_gpio.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/mpc52xx.h>
@@ -82,6 +84,14 @@ mpc5200_setup_xlb_arbiter(void)
         iounmap(xlb);
 }
 
+/*
+ * This variable is mapped in mpc52xx_map_common_devices and
+ * used in mpc5200_psc_ac97_gpio_reset().
+ */
+static DEFINE_SPINLOCK(gpio_lock);
+struct mpc52xx_gpio __iomem *simple_gpio;
+struct mpc52xx_gpio_wkup __iomem *wkup_gpio;
+
 /**
  * mpc52xx_declare_of_platform_devices: register internal devices and children
  *                                      of the localplus bus to the of_platform
@@ -109,6 +119,15 @@ static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
         { .compatible = "mpc5200-cdm", }, /* old */
         {}
 };
+static const struct of_device_id mpc52xx_gpio_simple[] = {
+        { .compatible = "fsl,mpc5200-gpio", },
+        {}
+};
+static const struct of_device_id mpc52xx_gpio_wkup[] = {
+        { .compatible = "fsl,mpc5200-gpio-wkup", },
+        {}
+};
+
 
 /**
  * mpc52xx_map_common_devices: iomap devices required by common code
@@ -135,6 +154,16 @@ mpc52xx_map_common_devices(void)
         np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
         mpc52xx_cdm = of_iomap(np, 0);
         of_node_put(np);
+
+        /* simple_gpio registers */
+        np = of_find_matching_node(NULL, mpc52xx_gpio_simple);
+        simple_gpio = of_iomap(np, 0);
+        of_node_put(np);
+
+        /* wkup_gpio registers */
+        np = of_find_matching_node(NULL, mpc52xx_gpio_wkup);
+        wkup_gpio = of_iomap(np, 0);
+        of_node_put(np);
 }
 
 /**
@@ -233,3 +262,80 @@ mpc52xx_restart(char *cmd)
 
         while (1);
 }
+
+#define PSC1_RESET     0x1
+#define PSC1_SYNC      0x4
+#define PSC1_SDATA_OUT 0x1
+#define PSC2_RESET     0x2
+#define PSC2_SYNC      (0x4<<4)
+#define PSC2_SDATA_OUT (0x1<<4)
+#define MPC52xx_GPIO_PSC1_MASK 0x7
+#define MPC52xx_GPIO_PSC2_MASK (0x7<<4)
+
+/**
+ * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus
+ *
+ * @psc: psc number to reset (only psc 1 and 2 support ac97)
+ */
+int mpc5200_psc_ac97_gpio_reset(int psc_number)
+{
+        unsigned long flags;
+        u32 gpio;
+        u32 mux;
+        int out;
+        int reset;
+        int sync;
+
+        if ((!simple_gpio) || (!wkup_gpio))
+                return -ENODEV;
+
+        switch (psc_number) {
+        case 0:
+                reset   = PSC1_RESET;           /* AC97_1_RES */
+                sync    = PSC1_SYNC;            /* AC97_1_SYNC */
+                out     = PSC1_SDATA_OUT;       /* AC97_1_SDATA_OUT */
+                gpio    = MPC52xx_GPIO_PSC1_MASK;
+                break;
+        case 1:
+                reset   = PSC2_RESET;           /* AC97_2_RES */
+                sync    = PSC2_SYNC;            /* AC97_2_SYNC */
+                out     = PSC2_SDATA_OUT;       /* AC97_2_SDATA_OUT */
+                gpio    = MPC52xx_GPIO_PSC2_MASK;
+                break;
+        default:
+                pr_err(__FILE__ ": Unable to determine PSC, no ac97 "
+                       "cold-reset will be performed\n");
+                return -ENODEV;
+        }
+
+        spin_lock_irqsave(&gpio_lock, flags);
+
+        /* Reconfiure pin-muxing to gpio */
+        mux = in_be32(&simple_gpio->port_config);
+        out_be32(&simple_gpio->port_config, mux & (~gpio));
+
+        /* enable gpio pins for output */
+        setbits8(&wkup_gpio->wkup_gpioe, reset);
+        setbits32(&simple_gpio->simple_gpioe, sync | out);
+
+        setbits8(&wkup_gpio->wkup_ddr, reset);
+        setbits32(&simple_gpio->simple_ddr, sync | out);
+
+        /* Assert cold reset */
+        clrbits32(&simple_gpio->simple_dvo, sync | out);
+        clrbits8(&wkup_gpio->wkup_dvo, reset);
+
+        /* wait at lease 1 us */
+        udelay(2);
+
+        /* Deassert reset */
+        setbits8(&wkup_gpio->wkup_dvo, reset);
+
+        /* Restore pin-muxing */
+        out_be32(&simple_gpio->port_config, mux);
+
+        spin_unlock_irqrestore(&gpio_lock, flags);
+
+        return 0;
+}
+EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset);