clk: samsung: pll: Add support for rate configuration of PLL45xx
This patch implements round_rate and set_rate callbacks of PLL45xx
driver to allow reconfiguration of PLL at runtime.
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index f2e92e8..4acd061 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -10,9 +10,12 @@
*/
#include <linux/errno.h>
+#include <linux/hrtimer.h>
#include "clk.h"
#include "clk-pll.h"
+#define PLL_TIMEOUT_MS 10
+
struct samsung_clk_pll {
struct clk_hw hw;
void __iomem *lock_reg;
@@ -272,13 +275,20 @@
/*
* PLL45xx Clock Type
*/
+#define PLL4502_LOCK_FACTOR 400
+#define PLL4508_LOCK_FACTOR 240
#define PLL45XX_MDIV_MASK (0x3FF)
#define PLL45XX_PDIV_MASK (0x3F)
#define PLL45XX_SDIV_MASK (0x7)
+#define PLL45XX_AFC_MASK (0x1F)
#define PLL45XX_MDIV_SHIFT (16)
#define PLL45XX_PDIV_SHIFT (8)
#define PLL45XX_SDIV_SHIFT (0)
+#define PLL45XX_AFC_SHIFT (0)
+
+#define PLL45XX_ENABLE BIT(31)
+#define PLL45XX_LOCKED BIT(29)
static unsigned long samsung_pll45xx_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
@@ -301,8 +311,101 @@
return (unsigned long)fvco;
}
+static bool samsung_pll45xx_mp_change(u32 pll_con0, u32 pll_con1,
+ const struct samsung_pll_rate_table *rate)
+{
+ u32 old_mdiv, old_pdiv, old_afc;
+
+ old_mdiv = (pll_con0 >> PLL45XX_MDIV_SHIFT) & PLL45XX_MDIV_MASK;
+ old_pdiv = (pll_con0 >> PLL45XX_PDIV_SHIFT) & PLL45XX_PDIV_MASK;
+ old_afc = (pll_con1 >> PLL45XX_AFC_SHIFT) & PLL45XX_AFC_MASK;
+
+ return (old_mdiv != rate->mdiv || old_pdiv != rate->pdiv
+ || old_afc != rate->afc);
+}
+
+static int samsung_pll45xx_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 con0, con1;
+ ktime_t start;
+
+ /* 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;
+ }
+
+ con0 = __raw_readl(pll->con_reg);
+ con1 = __raw_readl(pll->con_reg + 0x4);
+
+ if (!(samsung_pll45xx_mp_change(con0, con1, rate))) {
+ /* If only s change, change just s value only*/
+ con0 &= ~(PLL45XX_SDIV_MASK << PLL45XX_SDIV_SHIFT);
+ con0 |= rate->sdiv << PLL45XX_SDIV_SHIFT;
+ __raw_writel(con0, pll->con_reg);
+
+ return 0;
+ }
+
+ /* Set PLL PMS values. */
+ con0 &= ~((PLL45XX_MDIV_MASK << PLL45XX_MDIV_SHIFT) |
+ (PLL45XX_PDIV_MASK << PLL45XX_PDIV_SHIFT) |
+ (PLL45XX_SDIV_MASK << PLL45XX_SDIV_SHIFT));
+ con0 |= (rate->mdiv << PLL45XX_MDIV_SHIFT) |
+ (rate->pdiv << PLL45XX_PDIV_SHIFT) |
+ (rate->sdiv << PLL45XX_SDIV_SHIFT);
+
+ /* Set PLL AFC value. */
+ con1 = __raw_readl(pll->con_reg + 0x4);
+ con1 &= ~(PLL45XX_AFC_MASK << PLL45XX_AFC_SHIFT);
+ con1 |= (rate->afc << PLL45XX_AFC_SHIFT);
+
+ /* Set PLL lock time. */
+ switch (pll->type) {
+ case pll_4502:
+ __raw_writel(rate->pdiv * PLL4502_LOCK_FACTOR, pll->lock_reg);
+ break;
+ case pll_4508:
+ __raw_writel(rate->pdiv * PLL4508_LOCK_FACTOR, pll->lock_reg);
+ break;
+ default:
+ break;
+ };
+
+ /* Set new configuration. */
+ __raw_writel(con1, pll->con_reg + 0x4);
+ __raw_writel(con0, pll->con_reg);
+
+ /* Wait for locking. */
+ start = ktime_get();
+ while (!(__raw_readl(pll->con_reg) & PLL45XX_LOCKED)) {
+ ktime_t delta = ktime_sub(ktime_get(), start);
+
+ if (ktime_to_ms(delta) > PLL_TIMEOUT_MS) {
+ pr_err("%s: could not lock PLL %s\n",
+ __func__, __clk_get_name(hw->clk));
+ return -EFAULT;
+ }
+
+ cpu_relax();
+ }
+
+ return 0;
+}
+
static const struct clk_ops samsung_pll45xx_clk_ops = {
.recalc_rate = samsung_pll45xx_recalc_rate,
+ .round_rate = samsung_pll_round_rate,
+ .set_rate = samsung_pll45xx_set_rate,
+};
+
+static const struct clk_ops samsung_pll45xx_clk_min_ops = {
+ .recalc_rate = samsung_pll45xx_recalc_rate,
};
/*
@@ -591,9 +694,14 @@
init.ops = &samsung_pll35xx_clk_ops;
break;
case pll_4500:
+ init.ops = &samsung_pll45xx_clk_min_ops;
+ break;
case pll_4502:
case pll_4508:
- init.ops = &samsung_pll45xx_clk_ops;
+ if (!pll->rate_table)
+ init.ops = &samsung_pll45xx_clk_min_ops;
+ else
+ init.ops = &samsung_pll45xx_clk_ops;
break;
/* clk_ops for 36xx and 2650 are similar */
case pll_36xx: