diff options
Diffstat (limited to 'drivers/clk/clk-cs2000-cp.c')
| -rw-r--r-- | drivers/clk/clk-cs2000-cp.c | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/drivers/clk/clk-cs2000-cp.c b/drivers/clk/clk-cs2000-cp.c new file mode 100644 index 000000000000..7379de8dc894 --- /dev/null +++ b/drivers/clk/clk-cs2000-cp.c @@ -0,0 +1,510 @@ +/* + * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier + * + * Copyright (C) 2015 Renesas Electronics Corporation + * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> + * + * 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 <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/i2c.h> +#include <linux/of_device.h> +#include <linux/module.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) + +/* DEVICE_CFG1 */ +#define RSEL(x) (((x) & 0x3) << 3) +#define RSEL_MASK RSEL(0x3) +#define ENDEV1 (0x1) + +/* GLOBAL_CFG */ +#define ENDEV2 (0x1) + +#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; + struct clk *clk_out; +}; + +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, 0x3 << 3, val << 3); +} + +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_write(priv, DEVICE_CTRL, enable ? 0 : 0x3); +} + +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_write(priv, DEVICE_CFG2, 0x0); + 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; + + 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; + struct clk *clk; + 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; + + clk = clk_register(dev, &priv->hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + ret = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (ret < 0) { + clk_unregister(clk); + return ret; + } + + priv->clk_out = clk; + + 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_unregister(priv->clk_out); + + 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 struct i2c_driver cs2000_driver = { + .driver = { + .name = "cs2000-cp", + .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"); |