[PATCH 5/6] clk: ls1x: Update relationship among all clocks

[Kelvin Cheung]

- Add clock lookups for APB devices.
- Update clock relationship to make it more exact and clear.
_____
_______________________| |
OSC ___/ | MUX |___ XXX CLK
\___ PLL ___ XXX DIV ___| |
|_____|

Signed-off-by: Kelvin Cheung <***@gmail.com>
---
drivers/clk/clk-ls1x.c | 109 ++++++++++++++++++++++++++++++++++++-------------
1 file changed, 80 insertions(+), 29 deletions(-)

diff --git a/drivers/clk/clk-ls1x.c b/drivers/clk/clk-ls1x.c
index f20b750..ca80103 100644
--- a/drivers/clk/clk-ls1x.c
+++ b/drivers/clk/clk-ls1x.c
@@ -15,7 +15,8 @@

#include <loongson1.h>

-#define OSC 33
+#define OSC (33 * 1000000)
+#define DIV_APB 2

static DEFINE_SPINLOCK(_lock);

@@ -29,13 +30,12 @@ static void ls1x_pll_clk_disable(struct clk_hw *hw)
}

static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
- unsigned long parent_rate)
+ unsigned long parent_rate)
{
u32 pll, rate;

pll = __raw_readl(LS1X_CLK_PLL_FREQ);
- rate = ((12 + (pll & 0x3f)) * 1000000) +
- ((((pll >> 8) & 0x3ff) * 1000000) >> 10);
+ rate = 12 + (pll & 0x3f) + (((pll >> 8) & 0x3ff) >> 10);
rate *= OSC;
rate >>= 1;

@@ -48,8 +48,10 @@ static const struct clk_ops ls1x_pll_clk_ops = {
.recalc_rate = ls1x_pll_recalc_rate,
};

-static struct clk * __init clk_register_pll(struct device *dev,
- const char *name, const char *parent_name, unsigned long flags)
+static struct clk *__init clk_register_pll(struct device *dev,
+ const char *name,
+ const char *parent_name,
+ unsigned long flags)
{
struct clk_hw *hw;
struct clk *clk;
@@ -78,34 +80,83 @@ static struct clk * __init clk_register_pll(struct device *dev,
return clk;
}

+static const char const *cpu_parents[] = { "cpu_clk_div", "osc_33m_clk", };
+static const char const *ahb_parents[] = { "ahb_clk_div", "osc_33m_clk", };
+static const char const *dc_parents[] = { "dc_clk_div", "osc_33m_clk", };
+
void __init ls1x_clk_init(void)
{
struct clk *clk;

- clk = clk_register_pll(NULL, "pll_clk", NULL, CLK_IS_ROOT);
- clk_prepare_enable(clk);
-
- clk = clk_register_divider(NULL, "cpu_clk", "pll_clk",
- CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_CPU_SHIFT,
- DIV_CPU_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
- clk_prepare_enable(clk);
- clk_register_clkdev(clk, "cpu", NULL);
-
- clk = clk_register_divider(NULL, "dc_clk", "pll_clk",
- CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
- DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
- clk_prepare_enable(clk);
- clk_register_clkdev(clk, "dc", NULL);
-
- clk = clk_register_divider(NULL, "ahb_clk", "pll_clk",
- CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_DDR_SHIFT,
- DIV_DDR_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
- clk_prepare_enable(clk);
- clk_register_clkdev(clk, "ahb", NULL);
+ clk = clk_register_fixed_rate(NULL, "osc_33m_clk", NULL, CLK_IS_ROOT,
+ OSC);
+ clk_register_clkdev(clk, "osc_33m_clk", NULL);
+
+ /* clock derived from 33 MHz OSC clk */
+ clk = clk_register_pll(NULL, "pll_clk", "osc_33m_clk", 0);
+ clk_register_clkdev(clk, "pll_clk", NULL);
+
+ /* clock derived from PLL clk */
+ /* _____
+ * _______________________| |
+ * OSC ___/ | MUX |___ CPU CLK
+ * \___ PLL ___ CPU DIV ___| |
+ * |_____|
+ */
+ clk = clk_register_divider(NULL, "cpu_clk_div", "pll_clk",
+ CLK_GET_RATE_NOCACHE, LS1X_CLK_PLL_DIV,
+ DIV_CPU_SHIFT, DIV_CPU_WIDTH,
+ CLK_DIVIDER_ONE_BASED |
+ CLK_DIVIDER_ROUND_CLOSEST, &_lock);
+ clk_register_clkdev(clk, "cpu_clk_div", NULL);
+ clk = clk_register_mux(NULL, "cpu_clk", cpu_parents,
+ ARRAY_SIZE(cpu_parents),
+ CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+ BYPASS_CPU_SHIFT, BYPASS_CPU_WIDTH, 0, &_lock);
+ clk_register_clkdev(clk, "cpu_clk", NULL);
+
+ /* _____
+ * _______________________| |
+ * OSC ___/ | MUX |___ DC CLK
+ * \___ PLL ___ DC DIV ___| |
+ * |_____|
+ */
+ clk = clk_register_divider(NULL, "dc_clk_div", "pll_clk",
+ 0, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
+ DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
+ clk_register_clkdev(clk, "dc_clk_div", NULL);
+ clk = clk_register_mux(NULL, "dc_clk", dc_parents,
+ ARRAY_SIZE(dc_parents),
+ CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+ BYPASS_DC_SHIFT, BYPASS_DC_WIDTH, 0, &_lock);
+ clk_register_clkdev(clk, "dc_clk", NULL);
+
+ /* _____
+ * _______________________| |
+ * OSC ___/ | MUX |___ DDR CLK
+ * \___ PLL ___ DDR DIV ___| |
+ * |_____|
+ */
+ clk = clk_register_divider(NULL, "ahb_clk_div", "pll_clk",
+ 0, LS1X_CLK_PLL_DIV, DIV_DDR_SHIFT,
+ DIV_DDR_WIDTH, CLK_DIVIDER_ONE_BASED,
+ &_lock);
+ clk_register_clkdev(clk, "ahb_clk_div", NULL);
+ clk = clk_register_mux(NULL, "ahb_clk", ahb_parents,
+ ARRAY_SIZE(ahb_parents),
+ CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
+ BYPASS_DDR_SHIFT, BYPASS_DDR_WIDTH, 0, &_lock);
+ clk_register_clkdev(clk, "ahb_clk", NULL);
clk_register_clkdev(clk, "stmmaceth", NULL);

- clk = clk_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1, 2);
- clk_prepare_enable(clk);
- clk_register_clkdev(clk, "apb", NULL);
+ /* clock derived from AHB clk */
+ /* APB clk is always half of the AHB clk */
+ clk = clk_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
+ DIV_APB);
+ clk_register_clkdev(clk, "apb_clk", NULL);
+ clk_register_clkdev(clk, "ls1x_i2c", NULL);
+ clk_register_clkdev(clk, "ls1x_pwmtimer", NULL);
+ clk_register_clkdev(clk, "ls1x_spi", NULL);
+ clk_register_clkdev(clk, "ls1x_wdt", NULL);
clk_register_clkdev(clk, "serial8250", NULL);
}