[PATCH v2 3/5] clk: samsung: Add set_rate() clk_ops for PLL35xx

Vikas Sajjan
2013-05-29T13:37:55Z

From: Yadwinder Singh Brar <yadi.brar@samsung.com>

This patch add set_rate() and round_rate() for PLL35xx

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
---
drivers/clk/samsung/clk-pll.c | 103 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 102 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index 4b3b3f5..1fba7ef 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -27,6 +27,36 @@ struct samsung_clk_pll {
#define pll_writel(pll, val, offset) \
__raw_writel(val, (void __iomem *)(pll->base + (offset)));

+static const struct samsung_pll_rate_table *samsung_get_pll_settings(
+ struct samsung_clk_pll *pll, unsigned long rate)
+{
+ const struct samsung_pll_rate_table *rate_table = pll->rate_table;
+ int i;
+
+ for (i = 0; i < pll->rate_count; i++) {
+ if (rate == rate_table[i].rate)
+ return &rate_table[i];
+ }
+
+ return NULL;
+}
+
+static long samsung_pll_round_rate(struct clk_hw *hw,
+ unsigned long drate, unsigned long *prate)
+{
+ struct samsung_clk_pll *pll = to_clk_pll(hw);
+ const struct samsung_pll_rate_table *rate_table = pll->rate_table;
+ int i;
+
+ /* Assumming rate_table is in descending order */
+ for (i = 0; i < pll->rate_count; i++) {
+ if (drate >= rate_table[i].rate)
+ return rate_table[i].rate;
+ }
+
+ /* return minimum supported value */
+ return rate_table[i - 1].rate;
+}
/*
* PLL35xx Clock Type
*/
@@ -34,12 +64,17 @@ struct samsung_clk_pll {
#define PLL35XX_CON0_OFFSET 0x100
#define PLL35XX_CON1_OFFSET 0x104

+/* Maximum lock time can be 270 * PDIV cycles */
+#define PLL35XX_LOCK_FACTOR 270
+
#define PLL35XX_MDIV_MASK (0x3FF)
#define PLL35XX_PDIV_MASK (0x3F)
#define PLL35XX_SDIV_MASK (0x7)
+#define PLL35XX_LOCK_STAT_MASK (0x1)
#define PLL35XX_MDIV_SHIFT (16)
#define PLL35XX_PDIV_SHIFT (8)
#define PLL35XX_SDIV_SHIFT (0)
+#define PLL35XX_LOCK_STAT_SHIFT (29)

static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
@@ -59,8 +94,70 @@ static unsigned long samsung_pll35xx_recalc_rate(struct clk_hw *hw,
return (unsigned long)fvco;
}

+static inline bool samsung_pll35xx_mp_change(u32 mdiv, u32 pdiv, u32 pll_con)
+{
+ if ((mdiv != ((pll_con >> PLL35XX_MDIV_SHIFT) & PLL35XX_MDIV_MASK)) ||
+ (pdiv != ((pll_con >> PLL35XX_PDIV_SHIFT) & PLL35XX_PDIV_MASK)))
+ return 1;
+ else
+ return 0;
+}
+
+static int samsung_pll35xx_set_rate(struct clk_hw *hw, unsigned long drate,
+ unsigned long prate)
+{
+ struct samsung_clk_pll *pll = to_clk_pll(hw);
+ const struct samsung_pll_rate_table *rate;
+ u32 tmp;
+
+ /* Get required rate settings from table */
+ rate = samsung_get_pll_settings(pll, drate);
+ if (!rate) {
+ pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
+ drate, __clk_get_name(hw->clk));
+ return -EINVAL;
+ }
+
+ tmp = pll_readl(pll, PLL35XX_CON0_OFFSET);
+
+ if (!(samsung_pll35xx_mp_change(rate->mdiv, rate->pdiv, tmp))) {
+ /* If only s change, change just s value only*/
+ tmp &= ~(PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT);
+ tmp |= rate->sdiv << PLL35XX_SDIV_SHIFT;
+ pll_writel(pll, tmp, PLL35XX_CON0_OFFSET);
+ } else {
+ /* Set PLL lock time. */
+ pll_writel(pll, rate->pdiv * PLL35XX_LOCK_FACTOR,
+ PLL35XX_LOCK_OFFSET);
+
+ /* Change PLL PMS values */
+ tmp &= ~((PLL35XX_MDIV_MASK << PLL35XX_MDIV_SHIFT) |
+ (PLL35XX_PDIV_MASK << PLL35XX_PDIV_SHIFT) |
+ (PLL35XX_SDIV_MASK << PLL35XX_SDIV_SHIFT));
+ tmp |= (rate->mdiv << PLL35XX_MDIV_SHIFT) |
+ (rate->pdiv << PLL35XX_PDIV_SHIFT) |
+ (rate->sdiv << PLL35XX_SDIV_SHIFT);
+ pll_writel(pll, tmp, PLL35XX_CON0_OFFSET);
+
+ /* wait_lock_time */
+ do {
+ cpu_relax();
+ tmp = pll_readl(pll, PLL35XX_CON0_OFFSET);
+ } while (!(tmp & (PLL35XX_LOCK_STAT_MASK
+ << PLL35XX_LOCK_STAT_SHIFT)));
+ }
+
+ return 0;
+}
+
static const struct clk_ops samsung_pll35xx_clk_ops = {
.recalc_rate = samsung_pll35xx_recalc_rate,
+ .round_rate = samsung_pll_round_rate,
+ .set_rate = samsung_pll35xx_set_rate,
+};
+
+static const struct clk_ops samsung_pll35xx_clk_min_ops = {
+ .recalc_rate = samsung_pll35xx_recalc_rate,
};

struct clk * __init samsung_clk_register_pll35xx(const char *name,
@@ -79,11 +176,15 @@ struct clk * __init samsung_clk_register_pll35xx(const char *name,
}

init.name = name;
- init.ops = &samsung_pll35xx_clk_ops;
init.flags = CLK_GET_RATE_NOCACHE;
init.parent_names = &pname;
init.num_parents = 1;

+ if (rate_table && rate_count)
+ init.ops = &samsung_pll35xx_clk_ops;
+ else
+ init.ops = &samsung_pll35xx_clk_min_ops;
+
pll->hw.init = &init;
pll->base = base;
pll->rate_table = rate_table;
--
1.7.9.5