[PATCH v3 3/4] drivers: clk: st: Correct the pll-type for A9 for stih418
Gabriel Fernandez
gabriel.fernandez at linaro.org
Mon Oct 5 01:06:32 PDT 2015
Add support for new PLL-type for stih418 A9-PLL.
Currently the 407_A9_PLL type being used, it is corrected with this patch
4600c28 PLL allows to reach higher frequencies
so its programming algorithm is extended.
Signed-off-by: Pankaj Dev <pankaj.dev at st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez at linaro.org>
---
.../devicetree/bindings/clock/st/st,clkgen-pll.txt | 1 +
drivers/clk/st/clkgen-pll.c | 194 +++++++++++++++++++++
2 files changed, 195 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt b/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt
index e2c6db0..8f84c81 100644
--- a/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt
+++ b/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt
@@ -23,6 +23,7 @@ Required properties:
"st,stih407-plls-c32-a9", "st,clkgen-plls-c32"
"st,plls-c32-cx_0", "st,clkgen-plls-c32"
"st,plls-c32-cx_1", "st,clkgen-plls-c32"
+ "st,stih418-plls-c28-a9", "st,clkgen-plls-c32"
"st,stih415-gpu-pll-c32", "st,clkgengpu-pll-c32"
"st,stih416-gpu-pll-c32", "st,clkgengpu-pll-c32"
diff --git a/drivers/clk/st/clkgen-pll.c b/drivers/clk/st/clkgen-pll.c
index 22b6201..ba75cae 100644
--- a/drivers/clk/st/clkgen-pll.c
+++ b/drivers/clk/st/clkgen-pll.c
@@ -44,6 +44,13 @@ DEFINE_SPINLOCK(clkgen_a9_lock);
#define C32_MAX_ODFS (4)
+/*
+ * PLL configuration register bits for PLL4600 C28
+ */
+#define C28_NDIV_MASK (0xff)
+#define C28_IDF_MASK (0x7)
+#define C28_ODF_MASK (0x3f)
+
struct clkgen_pll_data {
struct clkgen_field pdn_status;
struct clkgen_field pdn_ctrl;
@@ -68,6 +75,7 @@ static const struct clk_ops st_pll800c65_ops;
static const struct clk_ops stm_pll3200c32_ops;
static const struct clk_ops stm_pll3200c32_a9_ops;
static const struct clk_ops st_pll1200c32_ops;
+static const struct clk_ops stm_pll4600c28_ops;
static const struct clkgen_pll_data st_pll1600c65_ax = {
.pdn_status = CLKGEN_FIELD(0x0, 0x1, 19),
@@ -256,6 +264,22 @@ static const struct clkgen_pll_data st_pll3200c32_407_a9 = {
.ops = &stm_pll3200c32_a9_ops,
};
+static struct clkgen_pll_data st_pll4600c28_418_a9 = {
+ /* 418 A9 */
+ .pdn_status = CLKGEN_FIELD(0x1a8, 0x1, 0),
+ .pdn_ctrl = CLKGEN_FIELD(0x1a8, 0x1, 0),
+ .locked_status = CLKGEN_FIELD(0x87c, 0x1, 0),
+ .ndiv = CLKGEN_FIELD(0x1b0, C28_NDIV_MASK, 0),
+ .idf = CLKGEN_FIELD(0x1a8, C28_IDF_MASK, 25),
+ .num_odfs = 1,
+ .odf = { CLKGEN_FIELD(0x1b0, C28_ODF_MASK, 8) },
+ .odf_gate = { CLKGEN_FIELD(0x1ac, 0x1, 28) },
+ .switch2pll_en = true,
+ .switch2pll = CLKGEN_FIELD(0x1a4, 0x1, 1),
+ .lock = &clkgen_a9_lock,
+ .ops = &stm_pll4600c28_ops,
+};
+
/**
* DOC: Clock Generated by PLL, rate set and enabled by bootloader
*
@@ -611,6 +635,163 @@ static unsigned long recalc_stm_pll1200c32(struct clk_hw *hw,
return rate;
}
+/* PLL output structure
+ * FVCO >> /2 >> FVCOBY2 (no output)
+ * |> Divider (ODF) >> PHI
+ *
+ * FVCOby2 output = (input * 2 * NDIV) / IDF (assuming FRAC_CONTROL==L)
+ *
+ * Rules:
+ * 4Mhz <= INFF input <= 350Mhz
+ * 4Mhz <= INFIN (INFF / IDF) <= 50Mhz
+ * 19.05Mhz <= FVCOby2 output (PHI w ODF=1) <= 3000Mhz
+ * 1 <= i (register/dec value for IDF) <= 7
+ * 8 <= n (register/dec value for NDIV) <= 246
+ */
+
+static int clk_pll4600c28_get_params(unsigned long input, unsigned long output,
+ struct stm_pll *pll)
+{
+
+ unsigned long i, infin, n;
+ unsigned long deviation = ~0;
+ unsigned long new_freq, new_deviation;
+
+ /* Output clock range: 19Mhz to 3000Mhz */
+ if (output < 19000000 || output > 3000000000u)
+ return -EINVAL;
+
+ /* For better jitter, IDF should be smallest and NDIV must be maximum */
+ for (i = 1; i <= 7 && deviation; i++) {
+ /* INFIN checks */
+ infin = input / i;
+ if (infin < 4000000 || infin > 50000000)
+ continue; /* Invalid case */
+
+ n = output / (infin * 2);
+ if (n < 8 || n > 246)
+ continue; /* Invalid case */
+ if (n < 246)
+ n++; /* To work around 'y' when n=x.y */
+
+ for (; n >= 8 && deviation; n--) {
+ new_freq = infin * 2 * n;
+ if (new_freq < output)
+ break; /* Optimization: shorting loop */
+
+ new_deviation = new_freq - output;
+ if (!new_deviation || new_deviation < deviation) {
+ pll->idf = i;
+ pll->ndiv = n;
+ deviation = new_deviation;
+ }
+ }
+ }
+
+ if (deviation == ~0) /* No solution found */
+ return -EINVAL;
+
+ return 0;
+}
+
+static int clk_pll4600c28_get_rate(unsigned long input, struct stm_pll *pll,
+ unsigned long *rate)
+{
+ if (!pll->idf)
+ pll->idf = 1;
+
+ *rate = (input / pll->idf) * 2 * pll->ndiv;
+
+ return 0;
+}
+
+static unsigned long recalc_stm_pll4600c28(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clkgen_pll *pll = to_clkgen_pll(hw);
+ struct stm_pll params;
+ unsigned long rate;
+
+ if (!clkgen_pll_is_enabled(hw) || !clkgen_pll_is_locked(hw))
+ return 0;
+
+ params.ndiv = CLKGEN_READ(pll, ndiv);
+ params.idf = CLKGEN_READ(pll, idf);
+
+ clk_pll4600c28_get_rate(parent_rate, ¶ms, &rate);
+
+ pr_debug("%s:%s rate %lu\n", __clk_get_name(hw->clk), __func__, rate);
+
+ return rate;
+}
+
+static long round_rate_stm_pll4600c28(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct stm_pll params;
+
+ if (!clk_pll4600c28_get_params(*prate, rate, ¶ms)) {
+ clk_pll4600c28_get_rate(*prate, ¶ms, &rate);
+ } else {
+ pr_debug("%s: %s rate %ld Invalid\n", __func__,
+ __clk_get_name(hw->clk), rate);
+ return 0;
+ }
+
+ pr_debug("%s: %s new rate %ld [ndiv=%u] [idf=%u]\n",
+ __func__, __clk_get_name(hw->clk),
+ rate, (unsigned int)params.ndiv,
+ (unsigned int)params.idf);
+
+ return rate;
+}
+
+static int set_rate_stm_pll4600c28(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clkgen_pll *pll = to_clkgen_pll(hw);
+ struct stm_pll params;
+ long hwrate;
+ unsigned long flags = 0;
+
+ if (!rate || !parent_rate)
+ return -EINVAL;
+
+ if (!clk_pll4600c28_get_params(parent_rate, rate, ¶ms)) {
+ clk_pll4600c28_get_rate(parent_rate, ¶ms, &hwrate);
+ } else {
+ pr_debug("%s: %s rate %ld Invalid\n", __func__,
+ __clk_get_name(hw->clk), rate);
+ return -EINVAL;
+ }
+
+ pr_debug("%s: %s new rate %ld [ndiv=0x%x] [idf=0x%x]\n",
+ __func__, __clk_get_name(hw->clk),
+ hwrate, (unsigned int)params.ndiv,
+ (unsigned int)params.idf);
+
+ if (!hwrate)
+ return -EINVAL;
+
+ pll->ndiv = params.ndiv;
+ pll->idf = params.idf;
+
+ __clkgen_pll_disable(hw);
+
+ if (pll->lock)
+ spin_lock_irqsave(pll->lock, flags);
+
+ CLKGEN_WRITE(pll, ndiv, pll->ndiv);
+ CLKGEN_WRITE(pll, idf, pll->idf);
+
+ if (pll->lock)
+ spin_unlock_irqrestore(pll->lock, flags);
+
+ __clkgen_pll_enable(hw);
+
+ return 0;
+}
+
static const struct clk_ops st_pll1600c65_ops = {
.enable = clkgen_pll_enable,
.disable = clkgen_pll_disable,
@@ -648,6 +829,15 @@ static const struct clk_ops st_pll1200c32_ops = {
.recalc_rate = recalc_stm_pll1200c32,
};
+static const struct clk_ops stm_pll4600c28_ops = {
+ .enable = clkgen_pll_enable,
+ .disable = clkgen_pll_disable,
+ .is_enabled = clkgen_pll_is_enabled,
+ .recalc_rate = recalc_stm_pll4600c28,
+ .round_rate = round_rate_stm_pll4600c28,
+ .set_rate = set_rate_stm_pll4600c28,
+};
+
static struct clk * __init clkgen_pll_register(const char *parent_name,
struct clkgen_pll_data *pll_data,
void __iomem *reg,
@@ -892,6 +1082,10 @@ static const struct of_device_id c32_pll_of_match[] = {
.compatible = "st,stih407-plls-c32-a9",
.data = &st_pll3200c32_407_a9,
},
+ {
+ .compatible = "st,stih418-plls-c28-a9",
+ .data = &st_pll4600c28_418_a9,
+ },
{}
};
--
1.9.1
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