From: Kuninori Morimoto <kuninori.morimoto...@renesas.com>
This patch adds CS2000 Fractional-N driver as clock provider.
It is useful if it supports runtime clock setting, but it supports
fixed clock rate at this point.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto...@renesas.com>
---
.../devicetree/bindings/misc/cs2000-cp.txt | 20 ++
drivers/misc/Kconfig | 6 +
drivers/misc/Makefile | 1 +
drivers/misc/cs2000-cp.c | 341 +++++++++++++++++++++
4 files changed, 368 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/cs2000-cp.txt
create mode 100644 drivers/misc/cs2000-cp.c
diff --git a/Documentation/devicetree/bindings/misc/cs2000-cp.txt
b/Documentation/devicetree/bindings/misc/cs2000-cp.txt
new file mode 100644
index 0000000..e79cf10
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/cs2000-cp.txt
@@ -0,0 +1,20 @@
+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-frequency: clock frequency of CLK_OUT
+
+Example:
+
+&i2c2 {
+ ...
+ cs2000: clk_multiplier@0x4f {
+ compatible = "cirrus,cs2000-cp";
+ reg = <0x4f>;
+ clocks = <&rcar_sound 0>, <&x12_clk>;
+ clock-frequency = <24576000>; /* 1/1 divide */
+ };
+};
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index ccccc29..deec03e 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -224,6 +224,12 @@ config SGI_XP
this feature will allow for direct communication between SSIs
based on a network adapter and DMA messaging.
+config CS2000_CP
+ tristate "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 CS5535_MFGPT
tristate "CS5535/CS5536 Geode Multi-Function General Purpose Timer
(MFGPT) support"
depends on MFD_CS5535
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 537d7f3b..36491e6 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_ENCLOSURE_SERVICES) += enclosure.o
obj-$(CONFIG_KGDB_TESTS) += kgdbts.o
obj-$(CONFIG_SGI_XP) += sgi-xp/
obj-$(CONFIG_SGI_GRU) += sgi-gru/
+obj-$(CONFIG_CS2000_CP) += cs2000-cp.o
obj-$(CONFIG_CS5535_MFGPT) += cs5535-mfgpt.o
obj-$(CONFIG_HP_ILO) += hpilo.o
obj-$(CONFIG_APDS9802ALS) += apds9802als.o
diff --git a/drivers/misc/cs2000-cp.c b/drivers/misc/cs2000-cp.c
new file mode 100644
index 0000000..be639e3
--- /dev/null
+++ b/drivers/misc/cs2000-cp.c
@@ -0,0 +1,341 @@
+/*
+ * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier
+ *
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ * Kuninori Morimoto <kuninori.morimoto...@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 CLK_MAIN 0 /* CLK_IN on datasheet */
+#define CLK_IN 1 /* REF_CLK on datasheet */
+
+#define CH_MAX 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 FUNC_CFG1 0x16
+#define FUNC_CFG2 0x17
+
+/* 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_ERR(ch) ((ch < 0) || (ch >= CH_MAX))
+
+struct cs2000_priv {
+ struct clk *clk_main;
+ struct clk *clk_in;
+ 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(c, addr) i2c_smbus_read_byte_data(c, addr)
+static void cs2000_write(struct i2c_client *client, u8 addr, u8 val)
+{
+ struct device *dev = &client->dev;
+
+ dev_dbg(dev, "0x%02x : 0x%02x\n", addr, val);
+
+ i2c_smbus_write_byte_data(client, addr, val);
+}
+
+static void cs2000_bset(struct i2c_client *client, u8 addr, u8 mask, u8 val)
+{
+ u32 data;
+
+ data = cs2000_read(client, addr);
+
+ data &= ~mask;
+ data |= (val & mask);
+
+ cs2000_write(client, addr, data);
+}
+
+static int cs2000_ratio_set(struct i2c_client *client,
+ int ch, u32 rate_in, u64 rate_out)
+{
+ u32 val;
+ int i;
+
+ if (CH_ERR(ch))
+ return -EINVAL;
+
+ /*
+ * ratio = rate_out / rate_in * 2^20
+ *
+ * To avoid over flow, rate_out is u64
+ * The result should be u32
+ */
+
+ val = rate_out * (1 << 20) / rate_in;
+ for (i = 0; i < 4; i++)
+ cs2000_write(client,
+ Ratio_Add(ch, i),
+ Ratio_Val(val, i));
+
+ return 0;
+}
+
+static int cs2000_ratio_select(struct i2c_client *client, int ch)
+{
+ if (CH_ERR(ch))
+ return -EINVAL;
+
+ /*
+ * FIXME
+ *
+ * this driver supports static ratio mode only
+ * at this point
+ */
+ cs2000_bset(client, DEVICE_CFG1, RSEL_MASK, RSEL(ch));
+ cs2000_write(client, DEVICE_CFG2, 0x0);
+
+ return 0;
+}
+
+static int cs2000_enable_dev_config(struct i2c_client *client)
+{
+ cs2000_bset(client, DEVICE_CFG1, ENDEV1, ENDEV1);
+ cs2000_bset(client, GLOBAL_CFG, ENDEV2, ENDEV2);
+
+ return 0;
+}
+
+static int cs2000_get_clk(struct i2c_client *client,
+ u32 *rate_in, u32 *rate_out)
+{
+ struct cs2000_priv *priv = i2c_get_clientdata(client);
+ struct device *dev = &client->dev;
+ struct device_node *np = dev->of_node;
+ struct clk *clk_main, *clk_in;
+
+ clk_main = of_clk_get(np, CLK_MAIN);
+ /* not yet provided */
+ if (IS_ERR(clk_main))
+ return -EPROBE_DEFER;
+
+ clk_in = of_clk_get(np, CLK_IN);
+ if (IS_ERR(clk_in))
+ return PTR_ERR(clk_in);
+
+ *rate_in = clk_get_rate(clk_in);
+
+ if (of_property_read_u32(np, "clock-frequency", rate_out))
+ return -EINVAL;
+
+ dev_dbg(dev, "%d -> %d\n",
+ *rate_in, *rate_out);
+
+ priv->clk_main = clk_main;
+ priv->clk_in = clk_in;
+
+ return 0;
+}
+
+static int cs2000_clk_in_bound_rate(struct i2c_client *client,
+ u32 rate_in)
+{
+ u32 val;
+
+ if ((32000000 <= rate_in) &&
+ (56000000 > rate_in))
+ val = 0x0;
+ else if ((16000000 <= rate_in) &&
+ (28000000 > rate_in))
+ val = 0x1;
+ else if ((8000000 <= rate_in) &&
+ (14000000 > rate_in))
+ val = 0x2;
+ else
+ return -EINVAL;
+
+ cs2000_bset(client, FUNC_CFG1, 0x3 << 3, val << 3);
+
+ return 0;
+}
+
+static int cs2000_wait_pll_lock(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ u32 val;
+ int i;
+
+ for (i = 0; i < 256; i++) {
+ val = cs2000_read(client, DEVICE_CTRL);
+ if (!(val & PLL_UNLOCK))
+ return 0;
+ udelay(1);
+ }
+
+ dev_err(dev, "pll lock failed\n");
+
+ return -EIO;
+}
+
+static int cs2000_enable_clk_out(struct i2c_client *client)
+{
+ /* enable both AUX_OUT, CLK_OUT */
+ cs2000_write(client, DEVICE_CTRL, 0x0);
+
+ return 0;
+}
+
+static int cs2000_register_clock(struct i2c_client *client)
+{
+ struct cs2000_priv *priv = i2c_get_clientdata(client);
+ struct device *dev = &client->dev;
+ struct device_node *np = dev->of_node;
+ struct clk *clk;
+ const char *parent_clk_name = __clk_get_name(priv->clk_in);
+ u32 rate;
+
+ if (of_property_read_u32(np, "clock-frequency", &rate))
+ return -EINVAL;
+
+ /*
+ * FIXME
+ *
+ * register this driver as fixed rate clock
+ * at this point
+ */
+ clk = clk_register_fixed_rate(dev, "clk_out", parent_clk_name,
+ (parent_clk_name) ? 0 : CLK_IS_ROOT,
+ rate);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ priv->clk_out = clk;
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+
+ return 0;
+}
+
+static int cs2000_version_print(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ u32 val = cs2000_read(client, DEVICE_ID);
+ char *revision;
+
+ /* CS2000 should be 0x0 */
+ if (0 != (val >> 3))
+ return -EIO;
+
+ switch (val & 0x7) {
+ case 0x4:
+ revision = "B2 / B3";
+ break;
+ case 0x6:
+ revision = "C1";
+ break;
+ default:
+ return -EIO;
+ }
+
+ dev_info(dev, "revision - %s\n", revision);
+
+ 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;
+ u32 rate_in = 0;
+ u32 rate_out = 0;
+ int ret;
+ int ch = 0;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, priv);
+
+ ret = cs2000_get_clk(client, &rate_in, &rate_out);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_enable_dev_config(client);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_clk_in_bound_rate(client, rate_in);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_ratio_set(client, ch, rate_in, rate_out);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_ratio_select(client, ch);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_wait_pll_lock(client);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_enable_clk_out(client);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_register_clock(client);
+ if (ret < 0)
+ return ret;
+
+ ret = cs2000_version_print(client);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static struct i2c_driver cs2000_driver = {
+ .driver = {
+ .name = "cs2000-cp",
+ .owner = THIS_MODULE,
+ .of_match_table = cs2000_of_match,
+ },
+ .probe = cs2000_probe,
+ .id_table = cs2000_id,
+};
+
+module_i2c_driver(cs2000_driver);
+
+MODULE_DESCRIPTION("CS2000-CP driver");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto...@renesas.com>");
+MODULE_LICENSE("GPL v2");
--
1.9.1
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