ASoC: Allow choice of ac97 gpio reset line

As the PXA27x series allow 2 gpios to reset the ac97 bus,
allow through platform data configuration the definition of
the correct gpio which will reset the AC97 bus.

This comes from a silicon defect on the PXA27x series, where
the gpio must be manually controlled in warm reset cases.

Signed-off-by: Robert Jarzmik <rjarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/include/sound/pxa2xx-lib.h b/include/sound/pxa2xx-lib.h
index 2fd3d25..2c894b6 100644 (file)
--- a/include/sound/pxa2xx-lib.h
+++ b/include/sound/pxa2xx-lib.h
@@ -42,4 +42,19 @@ extern int pxa2xx_ac97_hw_resume(void);
 extern int pxa2xx_ac97_hw_probe(struct platform_device *dev);
 extern void pxa2xx_ac97_hw_remove(struct platform_device *dev);
 
+/* AC97 platform_data */
+/**
+ * struct pxa2xx_ac97_platform_data - pxa ac97 platform data
+ * @reset_gpio: AC97 reset gpio (normally gpio113 or gpio95)
+ *              a -1 value means no gpio will be used for reset
+ *
+ * Platform data should only be specified for pxa27x CPUs where a silicon bug
+ * prevents correct operation of the reset line. If not specified, the default
+ * behaviour is to consider gpio 113 as the AC97 reset line, which is the
+ * default on most boards.
+ */
+struct pxa2xx_ac97_platform_data {
+       int reset_gpio;
+};
+
 #endif

diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c
index 35afd0c..d721ea7 100644 (file)
--- a/sound/arm/pxa2xx-ac97-lib.c
+++ b/sound/arm/pxa2xx-ac97-lib.c
@@ -31,6 +31,7 @@ static DECLARE_WAIT_QUEUE_HEAD(gsr_wq);
 static volatile long gsr_bits;
 static struct clk *ac97_clk;
 static struct clk *ac97conf_clk;
+static int reset_gpio;
 
 /*
  * Beware PXA27x bugs:
@@ -42,6 +43,45 @@ static struct clk *ac97conf_clk;
  * 1 jiffy timeout if interrupt never comes).
  */
 
+enum {
+       RESETGPIO_FORCE_HIGH,
+       RESETGPIO_FORCE_LOW,
+       RESETGPIO_NORMAL_ALTFUNC
+};
+
+/**
+ * set_resetgpio_mode - computes and sets the AC97_RESET gpio mode on PXA
+ * @mode: chosen action
+ *
+ * As the PXA27x CPUs suffer from a AC97 bug, a manual control of the reset line
+ * must be done to insure proper work of AC97 reset line.  This function
+ * computes the correct gpio_mode for further use by reset functions, and
+ * applied the change through pxa_gpio_mode.
+ */
+static void set_resetgpio_mode(int resetgpio_action)
+{
+       int mode = 0;
+
+       if (reset_gpio)
+               switch (resetgpio_action) {
+               case RESETGPIO_NORMAL_ALTFUNC:
+                       if (reset_gpio == 113)
+                               mode = 113 | GPIO_OUT | GPIO_DFLT_LOW;
+                       if (reset_gpio == 95)
+                               mode = 95 | GPIO_ALT_FN_1_OUT;
+                       break;
+               case RESETGPIO_FORCE_LOW:
+                       mode = reset_gpio | GPIO_OUT | GPIO_DFLT_LOW;
+                       break;
+               case RESETGPIO_FORCE_HIGH:
+                       mode = reset_gpio | GPIO_OUT | GPIO_DFLT_HIGH;
+                       break;
+               };
+
+       if (mode)
+               pxa_gpio_mode(mode);
+}
+
 unsigned short pxa2xx_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
 {
        unsigned short val = -1;
@@ -137,10 +177,10 @@ static inline void pxa_ac97_warm_pxa27x(void)
 
        /* warm reset broken on Bulverde,
           so manually keep AC97 reset high */
-       pxa_gpio_mode(113 | GPIO_OUT | GPIO_DFLT_HIGH);
+       set_resetgpio_mode(RESETGPIO_FORCE_HIGH);
        udelay(10);
        GCR |= GCR_WARM_RST;
-       pxa_gpio_mode(113 | GPIO_ALT_FN_2_OUT);
+       set_resetgpio_mode(RESETGPIO_NORMAL_ALTFUNC);
        udelay(500);
 }
 
@@ -308,8 +348,8 @@ int pxa2xx_ac97_hw_resume(void)
                pxa_gpio_mode(GPIO29_SDATA_IN_AC97_MD);
        }
        if (cpu_is_pxa27x()) {
-               /* Use GPIO 113 as AC97 Reset on Bulverde */
-               pxa_gpio_mode(113 | GPIO_ALT_FN_2_OUT);
+               /* Use GPIO 113 or 95 as AC97 Reset on Bulverde */
+               set_resetgpio_mode(RESETGPIO_NORMAL_ALTFUNC);
        }
        clk_enable(ac97_clk);
        return 0;
@@ -320,6 +360,27 @@ EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_resume);
 int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
 {
        int ret;
+       struct pxa2xx_ac97_platform_data *pdata = dev->dev.platform_data;
+
+       if (pdata) {
+               switch (pdata->reset_gpio) {
+               case 95:
+               case 113:
+                       reset_gpio = pdata->reset_gpio;
+                       break;
+               case 0:
+                       reset_gpio = 113;
+                       break;
+               case -1:
+                       break;
+               default:
+                       dev_err(dev, "Invalid reset GPIO %d\n",
+                               pdata->reset_gpio);
+               }
+       } else {
+               if (cpu_is_pxa27x())
+                       reset_gpio = 113;
+       }
 
        if (cpu_is_pxa25x() || cpu_is_pxa27x()) {
                pxa_gpio_mode(GPIO31_SYNC_AC97_MD);
@@ -330,7 +391,7 @@ int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
 
        if (cpu_is_pxa27x()) {
                /* Use GPIO 113 as AC97 Reset on Bulverde */
-               pxa_gpio_mode(113 | GPIO_ALT_FN_2_OUT);
+               set_resetgpio_mode(RESETGPIO_NORMAL_ALTFUNC);
                ac97conf_clk = clk_get(&dev->dev, "AC97CONFCLK");
                if (IS_ERR(ac97conf_clk)) {
                        ret = PTR_ERR(ac97conf_clk);