// SPDX-License-Identifier: GPL-2.0 /* * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier * * Copyright (C) 2015 Renesas Electronics Corporation * Kuninori Morimoto */ #include #include #include #include #include #include #include #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 "); MODULE_LICENSE("GPL v2");