2015-11-10 01:15:19

by Kuninori Morimoto

[permalink] [raw]
Subject: [PATCH v6] clk: add CS2000 Fractional-N driver

From: Kuninori Morimoto <[email protected]>

This patch adds CS2000 Fractional-N driver as clock provider.

Signed-off-by: Kuninori Morimoto <[email protected]>
---
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 <[email protected]>
+ *
+ * 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 <[email protected]>");
+MODULE_LICENSE("GPL v2");
--
1.9.1


2015-11-18 05:40:21

by Kuninori Morimoto

[permalink] [raw]
Subject: Re: [PATCH v6] clk: add CS2000 Fractional-N driver


Hi

ping ?

>
> From: Kuninori Morimoto <[email protected]>
>
> This patch adds CS2000 Fractional-N driver as clock provider.
>
> Signed-off-by: Kuninori Morimoto <[email protected]>
> ---
> 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 <[email protected]>
> + *
> + * 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 <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> --
> 1.9.1
>
> --
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> More majordomo info at http://vger.kernel.org/majordomo-info.html

2015-11-26 08:49:43

by Kuninori Morimoto

[permalink] [raw]
Subject: Re: [PATCH v6] clk: add CS2000 Fractional-N driver


Hi again

ping again ?

> ping ?
>
> >
> > From: Kuninori Morimoto <[email protected]>
> >
> > This patch adds CS2000 Fractional-N driver as clock provider.
> >
> > Signed-off-by: Kuninori Morimoto <[email protected]>
> > ---
> > 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 <[email protected]>
> > + *
> > + * 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 <[email protected]>");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 1.9.1
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-sh" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html

2015-12-01 00:36:07

by Stephen Boyd

[permalink] [raw]
Subject: Re: [PATCH v6] clk: add CS2000 Fractional-N driver

On 11/10, Kuninori Morimoto wrote:
> From: Kuninori Morimoto <[email protected]>
>
> This patch adds CS2000 Fractional-N driver as clock provider.
>
> Signed-off-by: Kuninori Morimoto <[email protected]>
> ---

Applied to clk-next

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