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path: root/drivers/clk/clk-cs2000-cp.c
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-rw-r--r--drivers/clk/clk-cs2000-cp.c634
1 files changed, 634 insertions, 0 deletions
diff --git a/drivers/clk/clk-cs2000-cp.c b/drivers/clk/clk-cs2000-cp.c
new file mode 100644
index 0000000000..35cb93ad29
--- /dev/null
+++ b/drivers/clk/clk-cs2000-cp.c
@@ -0,0 +1,634 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier
+ *
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ */
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define CH_MAX 4
+#define RATIO_REG_SIZE 4
+
+#define DEVICE_ID 0x1
+#define DEVICE_CTRL 0x2
+#define DEVICE_CFG1 0x3
+#define DEVICE_CFG2 0x4
+#define GLOBAL_CFG 0x5
+#define Ratio_Add(x, nth) (6 + (x * 4) + (nth))
+#define Ratio_Val(x, nth) ((x >> (24 - (8 * nth))) & 0xFF)
+#define Val_Ratio(x, nth) ((x & 0xFF) << (24 - (8 * nth)))
+#define FUNC_CFG1 0x16
+#define FUNC_CFG2 0x17
+
+/* DEVICE_ID */
+#define REVISION_MASK (0x7)
+#define REVISION_B2_B3 (0x4)
+#define REVISION_C1 (0x6)
+
+/* DEVICE_CTRL */
+#define PLL_UNLOCK (1 << 7)
+#define AUXOUTDIS (1 << 1)
+#define CLKOUTDIS (1 << 0)
+
+/* DEVICE_CFG1 */
+#define RSEL(x) (((x) & 0x3) << 3)
+#define RSEL_MASK RSEL(0x3)
+#define AUXOUTSRC(x) (((x) & 0x3) << 1)
+#define AUXOUTSRC_MASK AUXOUTSRC(0x3)
+#define ENDEV1 (0x1)
+
+/* DEVICE_CFG2 */
+#define AUTORMOD (1 << 3)
+#define LOCKCLK(x) (((x) & 0x3) << 1)
+#define LOCKCLK_MASK LOCKCLK(0x3)
+#define FRACNSRC_MASK (1 << 0)
+#define FRACNSRC_STATIC (0 << 0)
+#define FRACNSRC_DYNAMIC (1 << 0)
+
+/* GLOBAL_CFG */
+#define FREEZE (1 << 7)
+#define ENDEV2 (0x1)
+
+/* FUNC_CFG1 */
+#define CLKSKIPEN (1 << 7)
+#define REFCLKDIV(x) (((x) & 0x3) << 3)
+#define REFCLKDIV_MASK REFCLKDIV(0x3)
+
+/* FUNC_CFG2 */
+#define LFRATIO_MASK (1 << 3)
+#define LFRATIO_20_12 (0 << 3)
+#define LFRATIO_12_20 (1 << 3)
+
+#define CH_SIZE_ERR(ch) ((ch < 0) || (ch >= CH_MAX))
+#define hw_to_priv(_hw) container_of(_hw, struct cs2000_priv, hw)
+#define priv_to_client(priv) (priv->client)
+#define priv_to_dev(priv) (&(priv_to_client(priv)->dev))
+
+#define CLK_IN 0
+#define REF_CLK 1
+#define CLK_MAX 2
+
+static bool cs2000_readable_reg(struct device *dev, unsigned int reg)
+{
+ return reg > 0;
+}
+
+static bool cs2000_writeable_reg(struct device *dev, unsigned int reg)
+{
+ return reg != DEVICE_ID;
+}
+
+static bool cs2000_volatile_reg(struct device *dev, unsigned int reg)
+{
+ return reg == DEVICE_CTRL;
+}
+
+static const struct regmap_config cs2000_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = FUNC_CFG2,
+ .readable_reg = cs2000_readable_reg,
+ .writeable_reg = cs2000_writeable_reg,
+ .volatile_reg = cs2000_volatile_reg,
+};
+
+struct cs2000_priv {
+ struct clk_hw hw;
+ struct i2c_client *client;
+ struct clk *clk_in;
+ struct clk *ref_clk;
+ struct regmap *regmap;
+
+ bool dynamic_mode;
+ bool lf_ratio;
+ bool clk_skip;
+
+ /* suspend/resume */
+ unsigned long saved_rate;
+ unsigned long saved_parent_rate;
+};
+
+static const struct of_device_id cs2000_of_match[] = {
+ { .compatible = "cirrus,cs2000-cp", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, cs2000_of_match);
+
+static const struct i2c_device_id cs2000_id[] = {
+ { "cs2000-cp", },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, cs2000_id);
+
+static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable)
+{
+ int ret;
+
+ ret = regmap_update_bits(priv->regmap, DEVICE_CFG1, ENDEV1,
+ enable ? ENDEV1 : 0);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(priv->regmap, GLOBAL_CFG, ENDEV2,
+ enable ? ENDEV2 : 0);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(priv->regmap, FUNC_CFG1, CLKSKIPEN,
+ (enable && priv->clk_skip) ? CLKSKIPEN : 0);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int cs2000_ref_clk_bound_rate(struct cs2000_priv *priv,
+ u32 rate_in)
+{
+ u32 val;
+
+ if (rate_in >= 32000000 && rate_in < 56000000)
+ val = 0x0;
+ else if (rate_in >= 16000000 && rate_in < 28000000)
+ val = 0x1;
+ else if (rate_in >= 8000000 && rate_in < 14000000)
+ val = 0x2;
+ else
+ return -EINVAL;
+
+ return regmap_update_bits(priv->regmap, FUNC_CFG1,
+ REFCLKDIV_MASK,
+ REFCLKDIV(val));
+}
+
+static int cs2000_wait_pll_lock(struct cs2000_priv *priv)
+{
+ struct device *dev = priv_to_dev(priv);
+ unsigned int i, val;
+ int ret;
+
+ for (i = 0; i < 256; i++) {
+ ret = regmap_read(priv->regmap, DEVICE_CTRL, &val);
+ if (ret < 0)
+ return ret;
+ if (!(val & PLL_UNLOCK))
+ return 0;
+ udelay(1);
+ }
+
+ dev_err(dev, "pll lock failed\n");
+
+ return -ETIMEDOUT;
+}
+
+static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable)
+{
+ /* enable both AUX_OUT, CLK_OUT */
+ return regmap_update_bits(priv->regmap, DEVICE_CTRL,
+ (AUXOUTDIS | CLKOUTDIS),
+ enable ? 0 :
+ (AUXOUTDIS | CLKOUTDIS));
+}
+
+static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out, bool lf_ratio)
+{
+ u64 ratio;
+ u32 multiplier = lf_ratio ? 12 : 20;
+
+ /*
+ * ratio = rate_out / rate_in * 2^multiplier
+ *
+ * To avoid over flow, rate_out is u64.
+ * The result should be u32.
+ */
+ ratio = (u64)rate_out << multiplier;
+ do_div(ratio, rate_in);
+
+ return ratio;
+}
+
+static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in, bool lf_ratio)
+{
+ u64 rate_out;
+ u32 multiplier = lf_ratio ? 12 : 20;
+
+ /*
+ * ratio = rate_out / rate_in * 2^multiplier
+ *
+ * To avoid over flow, rate_out is u64.
+ * The result should be u32 or unsigned long.
+ */
+
+ rate_out = (u64)ratio * rate_in;
+ return rate_out >> multiplier;
+}
+
+static int cs2000_ratio_set(struct cs2000_priv *priv,
+ int ch, u32 rate_in, u32 rate_out)
+{
+ u32 val;
+ unsigned int i;
+ int ret;
+
+ if (CH_SIZE_ERR(ch))
+ return -EINVAL;
+
+ val = cs2000_rate_to_ratio(rate_in, rate_out, priv->lf_ratio);
+ for (i = 0; i < RATIO_REG_SIZE; i++) {
+ ret = regmap_write(priv->regmap,
+ Ratio_Add(ch, i),
+ Ratio_Val(val, i));
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch)
+{
+ unsigned int tmp, i;
+ u32 val;
+ int ret;
+
+ val = 0;
+ for (i = 0; i < RATIO_REG_SIZE; i++) {
+ ret = regmap_read(priv->regmap, Ratio_Add(ch, i), &tmp);
+ if (ret < 0)
+ return 0;
+
+ val |= Val_Ratio(tmp, i);
+ }
+
+ return val;
+}
+
+static int cs2000_ratio_select(struct cs2000_priv *priv, int ch)
+{
+ int ret;
+ u8 fracnsrc;
+
+ if (CH_SIZE_ERR(ch))
+ return -EINVAL;
+
+ ret = regmap_update_bits(priv->regmap, DEVICE_CFG1, RSEL_MASK, RSEL(ch));
+ if (ret < 0)
+ return ret;
+
+ fracnsrc = priv->dynamic_mode ? FRACNSRC_DYNAMIC : FRACNSRC_STATIC;
+
+ ret = regmap_update_bits(priv->regmap, DEVICE_CFG2,
+ AUTORMOD | LOCKCLK_MASK | FRACNSRC_MASK,
+ LOCKCLK(ch) | fracnsrc);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static unsigned long cs2000_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+ int ch = 0; /* it uses ch0 only at this point */
+ u32 ratio;
+
+ ratio = cs2000_ratio_get(priv, ch);
+
+ return cs2000_ratio_to_rate(ratio, parent_rate, priv->lf_ratio);
+}
+
+static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+ u32 ratio;
+
+ ratio = cs2000_rate_to_ratio(*parent_rate, rate, priv->lf_ratio);
+
+ return cs2000_ratio_to_rate(ratio, *parent_rate, priv->lf_ratio);
+}
+
+static int cs2000_select_ratio_mode(struct cs2000_priv *priv,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ /*
+ * From the datasheet:
+ *
+ * | It is recommended that the 12.20 High-Resolution format be
+ * | utilized whenever the desired ratio is less than 4096 since
+ * | the output frequency accuracy of the PLL is directly proportional
+ * | to the accuracy of the timing reference clock and the resolution
+ * | of the R_UD.
+ *
+ * This mode is only available in dynamic mode.
+ */
+ priv->lf_ratio = priv->dynamic_mode && ((rate / parent_rate) > 4096);
+
+ return regmap_update_bits(priv->regmap, FUNC_CFG2, LFRATIO_MASK,
+ priv->lf_ratio ? LFRATIO_20_12 : LFRATIO_12_20);
+}
+
+static int __cs2000_set_rate(struct cs2000_priv *priv, int ch,
+ unsigned long rate, unsigned long parent_rate)
+
+{
+ int ret;
+
+ ret = regmap_update_bits(priv->regmap, GLOBAL_CFG, FREEZE, FREEZE);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_select_ratio_mode(priv, rate, parent_rate);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_ratio_set(priv, ch, parent_rate, rate);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_ratio_select(priv, ch);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(priv->regmap, GLOBAL_CFG, FREEZE, 0);
+ if (ret < 0)
+ return ret;
+
+ priv->saved_rate = rate;
+ priv->saved_parent_rate = parent_rate;
+
+ return 0;
+}
+
+static int cs2000_set_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+ int ch = 0; /* it uses ch0 only at this point */
+
+ return __cs2000_set_rate(priv, ch, rate, parent_rate);
+}
+
+static int cs2000_set_saved_rate(struct cs2000_priv *priv)
+{
+ int ch = 0; /* it uses ch0 only at this point */
+
+ return __cs2000_set_rate(priv, ch,
+ priv->saved_rate,
+ priv->saved_parent_rate);
+}
+
+static int cs2000_enable(struct clk_hw *hw)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+ int ret;
+
+ ret = cs2000_enable_dev_config(priv, true);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_clk_out_enable(priv, true);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_wait_pll_lock(priv);
+ if (ret < 0)
+ return ret;
+
+ return ret;
+}
+
+static void cs2000_disable(struct clk_hw *hw)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+
+ cs2000_enable_dev_config(priv, false);
+
+ cs2000_clk_out_enable(priv, false);
+}
+
+static u8 cs2000_get_parent(struct clk_hw *hw)
+{
+ struct cs2000_priv *priv = hw_to_priv(hw);
+
+ /*
+ * In dynamic mode, output rates are derived from CLK_IN.
+ * In static mode, CLK_IN is ignored, so we return REF_CLK instead.
+ */
+ return priv->dynamic_mode ? CLK_IN : REF_CLK;
+}
+
+static const struct clk_ops cs2000_ops = {
+ .get_parent = cs2000_get_parent,
+ .recalc_rate = cs2000_recalc_rate,
+ .round_rate = cs2000_round_rate,
+ .set_rate = cs2000_set_rate,
+ .prepare = cs2000_enable,
+ .unprepare = cs2000_disable,
+};
+
+static int cs2000_clk_get(struct cs2000_priv *priv)
+{
+ struct device *dev = priv_to_dev(priv);
+ struct clk *clk_in, *ref_clk;
+
+ clk_in = devm_clk_get(dev, "clk_in");
+ /* not yet provided */
+ if (IS_ERR(clk_in))
+ return -EPROBE_DEFER;
+
+ ref_clk = devm_clk_get(dev, "ref_clk");
+ /* not yet provided */
+ if (IS_ERR(ref_clk))
+ return -EPROBE_DEFER;
+
+ priv->clk_in = clk_in;
+ priv->ref_clk = ref_clk;
+
+ return 0;
+}
+
+static int cs2000_clk_register(struct cs2000_priv *priv)
+{
+ struct device *dev = priv_to_dev(priv);
+ struct device_node *np = dev->of_node;
+ struct clk_init_data init;
+ const char *name = np->name;
+ static const char *parent_names[CLK_MAX];
+ u32 aux_out = 0;
+ int ref_clk_rate;
+ int ch = 0; /* it uses ch0 only at this point */
+ int ret;
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ priv->dynamic_mode = of_property_read_bool(np, "cirrus,dynamic-mode");
+ dev_info(dev, "operating in %s mode\n",
+ priv->dynamic_mode ? "dynamic" : "static");
+
+ of_property_read_u32(np, "cirrus,aux-output-source", &aux_out);
+ ret = regmap_update_bits(priv->regmap, DEVICE_CFG1,
+ AUXOUTSRC_MASK, AUXOUTSRC(aux_out));
+ if (ret < 0)
+ return ret;
+
+ priv->clk_skip = of_property_read_bool(np, "cirrus,clock-skip");
+
+ ref_clk_rate = clk_get_rate(priv->ref_clk);
+ ret = cs2000_ref_clk_bound_rate(priv, ref_clk_rate);
+ if (ret < 0)
+ return ret;
+
+ if (priv->dynamic_mode) {
+ /* Default to low-frequency mode to allow for large ratios */
+ priv->lf_ratio = true;
+ } else {
+ /*
+ * set default rate as 1/1.
+ * otherwise .set_rate which setup ratio
+ * is never called if user requests 1/1 rate
+ */
+ ret = __cs2000_set_rate(priv, ch, ref_clk_rate, ref_clk_rate);
+ if (ret < 0)
+ return ret;
+ }
+
+ parent_names[CLK_IN] = __clk_get_name(priv->clk_in);
+ parent_names[REF_CLK] = __clk_get_name(priv->ref_clk);
+
+ init.name = name;
+ init.ops = &cs2000_ops;
+ init.flags = CLK_SET_RATE_GATE;
+ init.parent_names = parent_names;
+ init.num_parents = ARRAY_SIZE(parent_names);
+
+ priv->hw.init = &init;
+
+ ret = clk_hw_register(dev, &priv->hw);
+ if (ret)
+ return ret;
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
+ if (ret < 0) {
+ clk_hw_unregister(&priv->hw);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int cs2000_version_print(struct cs2000_priv *priv)
+{
+ struct device *dev = priv_to_dev(priv);
+ const char *revision;
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(priv->regmap, DEVICE_ID, &val);
+ if (ret < 0)
+ return ret;
+
+ /* CS2000 should be 0x0 */
+ if (val >> 3)
+ return -EIO;
+
+ switch (val & REVISION_MASK) {
+ case REVISION_B2_B3:
+ revision = "B2 / B3";
+ break;
+ case REVISION_C1:
+ revision = "C1";
+ break;
+ default:
+ return -EIO;
+ }
+
+ dev_info(dev, "revision - %s\n", revision);
+
+ return 0;
+}
+
+static void cs2000_remove(struct i2c_client *client)
+{
+ struct cs2000_priv *priv = i2c_get_clientdata(client);
+ struct device *dev = priv_to_dev(priv);
+ struct device_node *np = dev->of_node;
+
+ of_clk_del_provider(np);
+
+ clk_hw_unregister(&priv->hw);
+}
+
+static int cs2000_probe(struct i2c_client *client)
+{
+ struct cs2000_priv *priv;
+ struct device *dev = &client->dev;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+ i2c_set_clientdata(client, priv);
+
+ priv->regmap = devm_regmap_init_i2c(client, &cs2000_regmap_config);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ ret = cs2000_clk_get(priv);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_clk_register(priv);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_version_print(priv);
+ if (ret < 0)
+ goto probe_err;
+
+ return 0;
+
+probe_err:
+ cs2000_remove(client);
+
+ return ret;
+}
+
+static int __maybe_unused cs2000_resume(struct device *dev)
+{
+ struct cs2000_priv *priv = dev_get_drvdata(dev);
+
+ return cs2000_set_saved_rate(priv);
+}
+
+static const struct dev_pm_ops cs2000_pm_ops = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(NULL, cs2000_resume)
+};
+
+static struct i2c_driver cs2000_driver = {
+ .driver = {
+ .name = "cs2000-cp",
+ .pm = &cs2000_pm_ops,
+ .of_match_table = cs2000_of_match,
+ },
+ .probe = cs2000_probe,
+ .remove = cs2000_remove,
+ .id_table = cs2000_id,
+};
+
+module_i2c_driver(cs2000_driver);
+
+MODULE_DESCRIPTION("CS2000-CP driver");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 02:31:49 +0000