[PATCH v3 5/5] phy: ti: am654-serdes: Support all clksel values
From: Kishon Vijay Abraham I
Date: Mon Mar 25 2019 - 04:09:37 EST
From: Roger Quadros <rogerq@xxxxxx>
Add support to select all 16 CLKSEL combinations that are shown in
"SerDes Reference Clock Distribution" in AM65 TRM.
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
drivers/phy/ti/phy-am654-serdes.c | 134 +++++++++++++++++++-----------
1 file changed, 84 insertions(+), 50 deletions(-)
diff --git a/drivers/phy/ti/phy-am654-serdes.c b/drivers/phy/ti/phy-am654-serdes.c
index dfbd2d48503d..f2d8d9b043cb 100644
--- a/drivers/phy/ti/phy-am654-serdes.c
+++ b/drivers/phy/ti/phy-am654-serdes.c
@@ -2,7 +2,7 @@
/**
* PCIe SERDES driver for AM654x SoC
*
- * Copyright (C) 2018 Texas Instruments
+ * Copyright (C) 2018 - 2019 Texas Instruments
* Author: Kishon Vijay Abraham I <kishon@xxxxxx>
*/
@@ -76,13 +76,14 @@
#define SERDES_NUM_CLOCKS 3
+#define AM654_SERDES_CTRL_CLKSEL_MASK GENMASK(7, 4)
+#define AM654_SERDES_CTRL_CLKSEL_SHIFT 4
+
struct serdes_am654_clk_mux {
struct clk_hw hw;
struct regmap *regmap;
unsigned int reg;
- int *table;
- u32 mask;
- u8 shift;
+ int clk_id;
struct clk_init_data clk_data;
};
@@ -269,31 +270,52 @@ static const struct phy_ops ops = {
.owner = THIS_MODULE,
};
+#define SERDES_NUM_MUX_COMBINATIONS 16
+
+#define LICLK 0
+#define EXT_REFCLK 1
+#define RICLK 2
+
+static const int
+serdes_am654_mux_table[SERDES_NUM_MUX_COMBINATIONS][SERDES_NUM_CLOCKS] = {
+ /*
+ * Each combination maps to one of
+ * "Figure 12-1986. SerDes Reference Clock Distribution"
+ * in TRM.
+ */
+ /* Parent of CMU refclk, Left output, Right output
+ * either of EXT_REFCLK, LICLK, RICLK
+ */
+ { EXT_REFCLK, EXT_REFCLK, EXT_REFCLK }, /* 0000 */
+ { RICLK, EXT_REFCLK, EXT_REFCLK }, /* 0001 */
+ { EXT_REFCLK, RICLK, LICLK }, /* 0010 */
+ { RICLK, RICLK, EXT_REFCLK }, /* 0011 */
+ { LICLK, EXT_REFCLK, EXT_REFCLK }, /* 0100 */
+ { EXT_REFCLK, EXT_REFCLK, EXT_REFCLK }, /* 0101 */
+ { LICLK, RICLK, LICLK }, /* 0110 */
+ { EXT_REFCLK, RICLK, LICLK }, /* 0111 */
+ { EXT_REFCLK, EXT_REFCLK, LICLK }, /* 1000 */
+ { RICLK, EXT_REFCLK, LICLK }, /* 1001 */
+ { EXT_REFCLK, RICLK, EXT_REFCLK }, /* 1010 */
+ { RICLK, RICLK, EXT_REFCLK }, /* 1011 */
+ { LICLK, EXT_REFCLK, LICLK }, /* 1100 */
+ { EXT_REFCLK, EXT_REFCLK, LICLK }, /* 1101 */
+ { LICLK, RICLK, EXT_REFCLK }, /* 1110 */
+ { EXT_REFCLK, RICLK, EXT_REFCLK }, /* 1111 */
+};
+
static u8 serdes_am654_clk_mux_get_parent(struct clk_hw *hw)
{
struct serdes_am654_clk_mux *mux = to_serdes_am654_clk_mux(hw);
- unsigned int num_parents = clk_hw_get_num_parents(hw);
struct regmap *regmap = mux->regmap;
unsigned int reg = mux->reg;
unsigned int val;
- int i;
regmap_read(regmap, reg, &val);
- val >>= mux->shift;
- val &= mux->mask;
-
- for (i = 0; i < num_parents; i++)
- if (mux->table[i] == val)
- return i;
-
- /*
- * No parent? This should never happen!
- * Verify if we set a valid parent in serdes_am654_clk_register()
- */
- WARN(1, "Failed to find the parent of %s clock\n", hw->init->name);
+ val &= AM654_SERDES_CTRL_CLKSEL_MASK;
+ val >>= AM654_SERDES_CTRL_CLKSEL_SHIFT;
- /* Make the parent lookup to fail */
- return num_parents;
+ return serdes_am654_mux_table[val][mux->clk_id];
}
static int serdes_am654_clk_mux_set_parent(struct clk_hw *hw, u8 index)
@@ -301,16 +323,52 @@ static int serdes_am654_clk_mux_set_parent(struct clk_hw *hw, u8 index)
struct serdes_am654_clk_mux *mux = to_serdes_am654_clk_mux(hw);
struct regmap *regmap = mux->regmap;
unsigned int reg = mux->reg;
- int val;
+ int clk_id = mux->clk_id;
+ int parents[SERDES_NUM_CLOCKS];
+ const int *p;
+ u32 val;
+ int found, i;
int ret;
- val = mux->table[index];
+ /* get existing setting */
+ regmap_read(regmap, reg, &val);
+ val &= AM654_SERDES_CTRL_CLKSEL_MASK;
+ val >>= AM654_SERDES_CTRL_CLKSEL_SHIFT;
+
+ for (i = 0; i < SERDES_NUM_CLOCKS; i++)
+ parents[i] = serdes_am654_mux_table[val][i];
+
+ /* change parent of this clock. others left intact */
+ parents[clk_id] = index;
+
+ /* Find the match */
+ for (val = 0; val < SERDES_NUM_MUX_COMBINATIONS; val++) {
+ p = serdes_am654_mux_table[val];
+ found = 1;
+ for (i = 0; i < SERDES_NUM_CLOCKS; i++) {
+ if (parents[i] != p[i]) {
+ found = 0;
+ break;
+ }
+ }
+
+ if (found)
+ break;
+ }
- if (val == -1)
+ if (!found) {
+ /*
+ * This can never happen, unless we missed
+ * a valid combination in serdes_am654_mux_table.
+ */
+ WARN(1, "Failed to find the parent of %s clock\n",
+ hw->init->name);
return -EINVAL;
+ }
- val <<= mux->shift;
- ret = regmap_update_bits(regmap, reg, mux->mask << mux->shift, val);
+ val <<= AM654_SERDES_CTRL_CLKSEL_SHIFT;
+ ret = regmap_update_bits(regmap, reg, AM654_SERDES_CTRL_CLKSEL_MASK,
+ val);
return ret;
}
@@ -320,21 +378,6 @@ static const struct clk_ops serdes_am654_clk_mux_ops = {
.get_parent = serdes_am654_clk_mux_get_parent,
};
-static int mux_table[SERDES_NUM_CLOCKS][3] = {
- /*
- * The entries represent values for selecting between
- * {left input, external reference clock, right input}
- * Only one of Left Output or Right Output should be used since
- * both left and right output clock uses the same bits and modifying
- * one clock will impact the other.
- */
- { BIT(2), 0, BIT(0) }, /* Mux of CMU refclk */
- { -1, BIT(3), BIT(1) }, /* Mux of Left Output */
- { BIT(1), BIT(3) | BIT(1), -1 }, /* Mux of Right Output */
-};
-
-static int mux_mask[SERDES_NUM_CLOCKS] = { 0x5, 0xa, 0xa };
-
static int serdes_am654_clk_register(struct serdes_am654 *am654_phy,
const char *clock_name, int clock_num)
{
@@ -394,20 +437,11 @@ static int serdes_am654_clk_register(struct serdes_am654 *am654_phy,
init->num_parents = num_parents;
init->name = clock_name;
- mux->table = mux_table[clock_num];
mux->regmap = regmap;
mux->reg = reg;
- mux->shift = 4;
- mux->mask = mux_mask[clock_num];
+ mux->clk_id = clock_num;
mux->hw.init = init;
- /*
- * setup a sane default so get_parent() call evaluates
- * to a valid parent. Index 1 is the safest choice as
- * the default as it is valid value for all of serdes's
- * output clocks.
- */
- serdes_am654_clk_mux_set_parent(&mux->hw, 1);
clk = devm_clk_register(dev, &mux->hw);
if (IS_ERR(clk))
return PTR_ERR(clk);
--
2.17.1