[AVR32] Make sure all genclocks have a parent

Initialize the parent field of each generic clock by looking at the
PM registers. This means that the genclock operations can always
assume that the parent field is non-null, so they don't have to
check. Also remove a few unnecessary BUG_ON()s.

Extracted from a patch by David Brownell.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

diff --git a/arch/avr32/mach-at32ap/at32ap7000.c b/arch/avr32/mach-at32ap/at32ap7000.c
index c1e477e..a5037aa 100644 (file)
--- a/arch/avr32/mach-at32ap/at32ap7000.c
+++ b/arch/avr32/mach-at32ap/at32ap7000.c
@@ -310,8 +310,6 @@ static void genclk_mode(struct clk *clk, int enabled)
 {
        u32 control;
 
-       BUG_ON(clk->index > 7);
-
        control = sm_readl(&system_manager, PM_GCCTRL + 4 * clk->index);
        if (enabled)
                control |= SM_BIT(CEN);
@@ -325,11 +323,6 @@ static unsigned long genclk_get_rate(struct clk *clk)
        u32 control;
        unsigned long div = 1;
 
-       BUG_ON(clk->index > 7);
-
-       if (!clk->parent)
-               return 0;
-
        control = sm_readl(&system_manager, PM_GCCTRL + 4 * clk->index);
        if (control & SM_BIT(DIVEN))
                div = 2 * (SM_BFEXT(DIV, control) + 1);
@@ -342,11 +335,6 @@ static long genclk_set_rate(struct clk *clk, unsigned long rate, int apply)
        u32 control;
        unsigned long parent_rate, actual_rate, div;
 
-       BUG_ON(clk->index > 7);
-
-       if (!clk->parent)
-               return 0;
-
        parent_rate = clk->parent->get_rate(clk->parent);
        control = sm_readl(&system_manager, PM_GCCTRL + 4 * clk->index);
 
@@ -373,11 +361,8 @@ int genclk_set_parent(struct clk *clk, struct clk *parent)
 {
        u32 control;
 
-       BUG_ON(clk->index > 7);
-
        printk("clk %s: new parent %s (was %s)\n",
-              clk->name, parent->name,
-              clk->parent ? clk->parent->name : "(null)");
+              clk->name, parent->name, clk->parent->name);
 
        control = sm_readl(&system_manager, PM_GCCTRL + 4 * clk->index);
 
@@ -399,6 +384,22 @@ int genclk_set_parent(struct clk *clk, struct clk *parent)
        return 0;
 }
 
+static void __init genclk_init_parent(struct clk *clk)
+{
+       u32 control;
+       struct clk *parent;
+
+       BUG_ON(clk->index > 7);
+
+       control = sm_readl(&system_manager, PM_GCCTRL + 4 * clk->index);
+       if (control & SM_BIT(OSCSEL))
+               parent = (control & SM_BIT(PLLSEL)) ? &pll1 : &osc1;
+       else
+               parent = (control & SM_BIT(PLLSEL)) ? &pll0 : &osc0;
+
+       clk->parent = parent;
+}
+
 /* --------------------------------------------------------------------
  *  System peripherals
  * -------------------------------------------------------------------- */
@@ -872,6 +873,50 @@ at32_add_device_lcdc(unsigned int id, struct lcdc_platform_data *data)
        return pdev;
 }
 
+/* --------------------------------------------------------------------
+ *  GCLK
+ * -------------------------------------------------------------------- */
+static struct clk gclk0 = {
+       .name           = "gclk0",
+       .mode           = genclk_mode,
+       .get_rate       = genclk_get_rate,
+       .set_rate       = genclk_set_rate,
+       .set_parent     = genclk_set_parent,
+       .index          = 0,
+};
+static struct clk gclk1 = {
+       .name           = "gclk1",
+       .mode           = genclk_mode,
+       .get_rate       = genclk_get_rate,
+       .set_rate       = genclk_set_rate,
+       .set_parent     = genclk_set_parent,
+       .index          = 1,
+};
+static struct clk gclk2 = {
+       .name           = "gclk2",
+       .mode           = genclk_mode,
+       .get_rate       = genclk_get_rate,
+       .set_rate       = genclk_set_rate,
+       .set_parent     = genclk_set_parent,
+       .index          = 2,
+};
+static struct clk gclk3 = {
+       .name           = "gclk3",
+       .mode           = genclk_mode,
+       .get_rate       = genclk_get_rate,
+       .set_rate       = genclk_set_rate,
+       .set_parent     = genclk_set_parent,
+       .index          = 3,
+};
+static struct clk gclk4 = {
+       .name           = "gclk4",
+       .mode           = genclk_mode,
+       .get_rate       = genclk_get_rate,
+       .set_rate       = genclk_set_rate,
+       .set_parent     = genclk_set_parent,
+       .index          = 4,
+};
+
 struct clk *at32_clock_list[] = {
        &osc32k,
        &osc0,
@@ -908,6 +953,11 @@ struct clk *at32_clock_list[] = {
        &atmel_spi1_spi_clk,
        &lcdc0_hclk,
        &lcdc0_pixclk,
+       &gclk0,
+       &gclk1,
+       &gclk2,
+       &gclk3,
+       &gclk4,
 };
 unsigned int at32_nr_clocks = ARRAY_SIZE(at32_clock_list);
 
@@ -936,6 +986,13 @@ void __init at32_clock_init(void)
        if (sm_readl(sm, PM_PLL1) & SM_BIT(PLLOSC))
                pll1.parent = &osc1;
 
+       genclk_init_parent(&gclk0);
+       genclk_init_parent(&gclk1);
+       genclk_init_parent(&gclk2);
+       genclk_init_parent(&gclk3);
+       genclk_init_parent(&gclk4);
+       genclk_init_parent(&lcdc0_pixclk);
+
        /*
         * Turn on all clocks that have at least one user already, and
         * turn off everything else. We only do this for module