/* * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier * * Copyright (C) 2015 Renesas Electronics Corporation * Kuninori Morimoto * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #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 ENDEV1 (0x1) /* DEVICE_CFG2 */ #define AUTORMOD (1 << 3) #define LOCKCLK(x) (((x) & 0x3) << 1) #define LOCKCLK_MASK LOCKCLK(0x3) #define FRACNSRC (1 << 0) /* GLOBAL_CFG */ #define ENDEV2 (0x1) /* FUNC_CFG1 */ #define REFCLKDIV(x) (((x) & 0x3) << 3) #define REFCLKDIV_MASK REFCLKDIV(0x3) #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 struct cs2000_priv { struct clk_hw hw; struct i2c_client *client; struct clk *clk_in; struct clk *ref_clk; /* 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); #define cs2000_read(priv, addr) \ i2c_smbus_read_byte_data(priv_to_client(priv), addr) #define cs2000_write(priv, addr, val) \ i2c_smbus_write_byte_data(priv_to_client(priv), addr, val) static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val) { s32 data; data = cs2000_read(priv, addr); if (data < 0) return data; data &= ~mask; data |= (val & mask); return cs2000_write(priv, addr, data); } static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable) { int ret; ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1, enable ? ENDEV1 : 0); if (ret < 0) return ret; ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2, enable ? ENDEV2 : 0); if (ret < 0) return ret; return 0; } static int cs2000_clk_in_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 cs2000_bset(priv, FUNC_CFG1, REFCLKDIV_MASK, REFCLKDIV(val)); } static int cs2000_wait_pll_lock(struct cs2000_priv *priv) { struct device *dev = priv_to_dev(priv); s32 val; unsigned int i; for (i = 0; i < 256; i++) { val = cs2000_read(priv, DEVICE_CTRL); if (val < 0) return val; 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 cs2000_bset(priv, DEVICE_CTRL, (AUXOUTDIS | CLKOUTDIS), enable ? 0 : (AUXOUTDIS | CLKOUTDIS)); } static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out) { u64 ratio; /* * ratio = rate_out / rate_in * 2^20 * * To avoid over flow, rate_out is u64. * The result should be u32. */ ratio = (u64)rate_out << 20; do_div(ratio, rate_in); return ratio; } static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in) { u64 rate_out; /* * ratio = rate_out / rate_in * 2^20 * * 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 >> 20; } 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); for (i = 0; i < RATIO_REG_SIZE; i++) { ret = cs2000_write(priv, 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) { s32 tmp; u32 val; unsigned int i; val = 0; for (i = 0; i < RATIO_REG_SIZE; i++) { tmp = cs2000_read(priv, Ratio_Add(ch, i)); if (tmp < 0) return 0; val |= Val_Ratio(tmp, i); } return val; } static int cs2000_ratio_select(struct cs2000_priv *priv, int ch) { int ret; if (CH_SIZE_ERR(ch)) return -EINVAL; /* * FIXME * * this driver supports static ratio mode only at this point. */ ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch)); if (ret < 0) return ret; ret = cs2000_bset(priv, DEVICE_CFG2, (AUTORMOD | LOCKCLK_MASK | FRACNSRC), 0); 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); } static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate) { u32 ratio; ratio = cs2000_rate_to_ratio(*parent_rate, rate); return cs2000_ratio_to_rate(ratio, *parent_rate); } static int __cs2000_set_rate(struct cs2000_priv *priv, int ch, unsigned long rate, unsigned long parent_rate) { int ret; ret = cs2000_clk_in_bound_rate(priv, 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; 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_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) { /* always return REF_CLK */ return 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 i2c_client *client = priv_to_client(priv); struct device *dev = &client->dev; 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]; int ch = 0; /* it uses ch0 only at this point */ int rate; int ret; of_property_read_string(np, "clock-output-names", &name); /* * set default rate as 1/1. * otherwise .set_rate which setup ratio * is never called if user requests 1/1 rate */ rate = clk_get_rate(priv->ref_clk); ret = __cs2000_set_rate(priv, ch, rate, 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 i2c_client *client = priv_to_client(priv); struct device *dev = &client->dev; s32 val; const char *revision; val = cs2000_read(priv, DEVICE_ID); if (val < 0) return val; /* 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 int cs2000_remove(struct i2c_client *client) { struct cs2000_priv *priv = i2c_get_clientdata(client); struct device *dev = &client->dev; struct device_node *np = dev->of_node; of_clk_del_provider(np); clk_hw_unregister(&priv->hw); return 0; } static int cs2000_probe(struct i2c_client *client, const struct i2c_device_id *id) { 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); 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 cs2000_resume(struct device *dev) { struct cs2000_priv *priv = dev_get_drvdata(dev); int ch = 0; /* it uses ch0 only at this point */ return __cs2000_set_rate(priv, ch, priv->saved_rate, priv->saved_parent_rate); } static const struct dev_pm_ops cs2000_pm_ops = { .resume_early = 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");