Thread (28 messages) 28 messages, 4 authors, 2013-08-22
STALE4719d

[PATCH 10/16] clk: samsung: pll: Add support for rate configuration of PLL45xx

From: Yadwinder Singh Brar <hidden>
Date: 2013-08-21 12:18:44
Also in: linux-samsung-soc

Hi Tomasz,

On Tue, Aug 20, 2013 at 11:01 PM, Tomasz Figa [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This patch implements round_rate and set_rate callbacks of PLL45xx
driver to allow reconfiguration of PLL at runtime.

Signed-off-by: Tomasz Figa <redacted>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/clk/samsung/clk-pll.c | 109 +++++++++++++++++++++++++++++++++++++++++-
 drivers/clk/samsung/clk-pll.h |  10 ++++
 2 files changed, 118 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index b0398d2..cb971cb 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 @@ static const struct clk_ops samsung_pll36xx_clk_min_ops = {
 /*
  * 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 +311,100 @@ static unsigned long samsung_pll45xx_recalc_rate(struct clk_hw *hw,
        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;
old_afc doesn't required in this function.
+
+       return (old_mdiv != rate->mdiv || old_pdiv != rate->pdiv);
+}
+
+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);
+
Do we need to take care of AFC_ENB also, if we are using AFC ?

Regards,
Yadwinder
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