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SubjectRe: [PATCH v6] clk: add CS2000 Fractional-N driver
Date

Hi

ping ?

>
> From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
>
> This patch adds CS2000 Fractional-N driver as clock provider.
>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
> ---
> v5 -> v6
>
> - remove redundant variable from each functions
> - multi line code become one line
> - end of comment has dot
> - cs2000_wait_pll_lock() returns -ETIMEDOUT instead of -EIO
> - removed explicit casting from ratio function
> - removed magic number
>
> .../devicetree/bindings/clock/cs2000-cp.txt | 22 +
> drivers/clk/Kconfig | 6 +
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-cs2000-cp.c | 509 +++++++++++++++++++++
> 4 files changed, 538 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/cs2000-cp.txt
> create mode 100644 drivers/clk/clk-cs2000-cp.c
>
> diff --git a/Documentation/devicetree/bindings/clock/cs2000-cp.txt b/Documentation/devicetree/bindings/clock/cs2000-cp.txt
> new file mode 100644
> index 0000000..54e6df0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/cs2000-cp.txt
> @@ -0,0 +1,22 @@
> +CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier
> +
> +Required properties:
> +
> +- compatible: "cirrus,cs2000-cp"
> +- reg: The chip select number on the I2C bus
> +- clocks: common clock binding for CLK_IN, XTI/REF_CLK
> +- clock-names: CLK_IN : clk_in, XTI/REF_CLK : ref_clk
> +- #clock-cells: must be <0>
> +
> +Example:
> +
> +&i2c2 {
> + ...
> + cs2000: clk_multiplier@4f {
> + #clock-cells = <0>;
> + compatible = "cirrus,cs2000-cp";
> + reg = <0x4f>;
> + clocks = <&rcar_sound 0>, <&x12_clk>;
> + clock-names = "clk_in", "ref_clk";
> + };
> +};
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index a1fa611..b8c347f 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -116,6 +116,12 @@ config COMMON_CLK_CDCE925
> Given a target output frequency, the driver will set the PLL and
> divider to best approximate the desired output.
>
> +config COMMON_CLK_CS2000_CP
> + tristate "Clock driver for CS2000 Fractional-N Clock Synthesizer & Clock Multiplier"
> + depends on I2C
> + help
> + If you say yes here you get support for the CS2000 clock multiplier.
> +
> config COMMON_CLK_S2MPS11
> tristate "Clock driver for S2MPS1X/S5M8767 MFD"
> depends on MFD_SEC_CORE
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 366350a..86afe50 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_MACH_ASM9260) += clk-asm9260.o
> obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
> obj-$(CONFIG_ARCH_AXXIA) += clk-axm5516.o
> obj-$(CONFIG_COMMON_CLK_CDCE706) += clk-cdce706.o
> +obj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
> obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
> obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
> obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
> diff --git a/drivers/clk/clk-cs2000-cp.c b/drivers/clk/clk-cs2000-cp.c
> new file mode 100644
> index 0000000..cc90d87
> --- /dev/null
> +++ b/drivers/clk/clk-cs2000-cp.c
> @@ -0,0 +1,509 @@
> +/*
> + * 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)
> +{
> + u32 tmp, 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");
> --
> 1.9.1
>
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