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[25/35] davinci: add support for CDCE949 clock synthesizer

Message ID 1262802737-6601-26-git-send-email-khilman@deeprootsystems.com (mailing list archive)
State Accepted
Headers show

Commit Message

Kevin Hilman Jan. 6, 2010, 6:32 p.m. UTC
None
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Patch

diff --git a/arch/arm/mach-davinci/cdce949.c b/arch/arm/mach-davinci/cdce949.c
new file mode 100644
index 0000000..5a08283
--- /dev/null
+++ b/arch/arm/mach-davinci/cdce949.c
@@ -0,0 +1,289 @@ 
+/*
+ * TI CDCE949 clock synthesizer driver
+ *
+ * Note: This implementation assumes an input of 27MHz to the CDCE.
+ * This is by no means constrained by CDCE hardware although the datasheet
+ * does use this as an example for all illustrations and more importantly:
+ * that is the crystal input on boards it is currently used on.
+ *
+ * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.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/kernel.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#include <mach/clock.h>
+
+#include "clock.h"
+
+static struct i2c_client *cdce_i2c_client;
+
+/* CDCE register descriptor */
+struct cdce_reg {
+	u8	addr;
+	u8	val;
+};
+
+/* Per-Output (Y1, Y2 etc.) frequency descriptor */
+struct cdce_freq {
+	/* Frequency in KHz */
+	unsigned long frequency;
+	/*
+	 * List of registers to program to obtain a particular frequency.
+	 * 0x0 in register address and value is the end of list marker.
+	 */
+	struct cdce_reg *reglist;
+};
+
+#define CDCE_FREQ_TABLE_ENTRY(line, out)		\
+{							\
+	.reglist	= cdce_y ##line## _ ##out,		\
+	.frequency	= out,				\
+}
+
+/* List of CDCE outputs  */
+struct cdce_output {
+	/* List of frequencies on this output */
+	struct cdce_freq *freq_table;
+	/* Number of possible frequencies */
+	int size;
+};
+
+/*
+ * Finding out the values to program into CDCE949 registers for a particular
+ * frequency output is not a simple calculation. Have a look at the datasheet
+ * for the details. There is desktop software available to help users with
+ * the calculations. Here, we just depend on the output of that software
+ * (or hand calculations) instead trying to runtime calculate the register
+ * values and inflicting misery on ourselves.
+ */
+static struct cdce_reg cdce_y1_148500[] = {
+	{ 0x13, 0x00 },
+	/* program PLL1_0 multiplier */
+	{ 0x18, 0xaf },
+	{ 0x19, 0x50 },
+	{ 0x1a, 0x02 },
+	{ 0x1b, 0xc9 },
+	/* program PLL1_11 multiplier */
+	{ 0x1c, 0x00 },
+	{ 0x1d, 0x40 },
+	{ 0x1e, 0x02 },
+	{ 0x1f, 0xc9 },
+	/* output state selection */
+	{ 0x15, 0x00 },
+	{ 0x14, 0xef },
+	/* switch MUX to PLL1 output */
+	{ 0x14, 0x6f },
+	{ 0x16, 0x06 },
+	/* set P2DIV divider, P3DIV and input crystal */
+	{ 0x17, 0x06 },
+	{ 0x01, 0x00 },
+	{ 0x05, 0x48 },
+	{ 0x02, 0x80 },
+	/* enable and disable PLL */
+	{ 0x02, 0xbc },
+	{ 0x03, 0x01 },
+	{ },
+};
+
+static struct cdce_reg cdce_y1_74250[] = {
+	{ 0x13, 0x00 },
+	{ 0x18, 0xaf },
+	{ 0x19, 0x50 },
+	{ 0x1a, 0x02 },
+	{ 0x1b, 0xc9 },
+	{ 0x1c, 0x00 },
+	{ 0x1d, 0x40 },
+	{ 0x1e, 0x02 },
+	{ 0x1f, 0xc9 },
+	/* output state selection */
+	{ 0x15, 0x00 },
+	{ 0x14, 0xef },
+	/* switch MUX to PLL1 output */
+	{ 0x14, 0x6f },
+	{ 0x16, 0x06 },
+	/* set P2DIV divider, P3DIV and input crystal */
+	{ 0x17, 0x06 },
+	{ 0x01, 0x00 },
+	{ 0x05, 0x48 },
+	{ 0x02, 0x80 },
+	/* enable and disable PLL */
+	{ 0x02, 0xbc },
+	{ 0x03, 0x02 },
+	{ },
+};
+
+static struct cdce_reg cdce_y1_27000[] = {
+	{ 0x13, 0x00 },
+	{ 0x18, 0x00 },
+	{ 0x19, 0x40 },
+	{ 0x1a, 0x02 },
+	{ 0x1b, 0x08 },
+	{ 0x1c, 0x00 },
+	{ 0x1d, 0x40 },
+	{ 0x1e, 0x02 },
+	{ 0x1f, 0x08 },
+	{ 0x15, 0x02 },
+	{ 0x14, 0xed },
+	{ 0x16, 0x01 },
+	{ 0x17, 0x01 },
+	{ 0x01, 0x00 },
+	{ 0x05, 0x50 },
+	{ 0x02, 0xb4 },
+	{ 0x03, 0x01 },
+	{ },
+};
+
+static struct cdce_freq cdce_y1_freqs[] = {
+	CDCE_FREQ_TABLE_ENTRY(1, 148500),
+	CDCE_FREQ_TABLE_ENTRY(1, 74250),
+	CDCE_FREQ_TABLE_ENTRY(1, 27000),
+};
+
+static struct cdce_reg cdce_y5_13500[] = {
+	{ 0x27, 0x08 },
+	{ 0x28, 0x00 },
+	{ 0x29, 0x40 },
+	{ 0x2a, 0x02 },
+	{ 0x2b, 0x08 },
+	{ 0x24, 0x6f },
+	{ },
+};
+
+static struct cdce_reg cdce_y5_16875[] = {
+	{ 0x27, 0x08 },
+	{ 0x28, 0x9f },
+	{ 0x29, 0xb0 },
+	{ 0x2a, 0x02 },
+	{ 0x2b, 0x89 },
+	{ 0x24, 0x6f },
+	{ },
+};
+
+static struct cdce_reg cdce_y5_27000[] = {
+	{ 0x27, 0x04 },
+	{ 0x28, 0x00 },
+	{ 0x29, 0x40 },
+	{ 0x2a, 0x02 },
+	{ 0x2b, 0x08 },
+	{ 0x24, 0x6f },
+	{ },
+};
+static struct cdce_reg cdce_y5_54000[] = {
+	{ 0x27, 0x04 },
+	{ 0x28, 0xff },
+	{ 0x29, 0x80 },
+	{ 0x2a, 0x02 },
+	{ 0x2b, 0x07 },
+	{ 0x24, 0x6f },
+	{ },
+};
+
+static struct cdce_reg cdce_y5_81000[] = {
+	{ 0x27, 0x02 },
+	{ 0x28, 0xbf },
+	{ 0x29, 0xa0 },
+	{ 0x2a, 0x03 },
+	{ 0x2b, 0x0a },
+	{ 0x24, 0x6f },
+	{ },
+};
+
+static struct cdce_freq cdce_y5_freqs[] = {
+	CDCE_FREQ_TABLE_ENTRY(5, 13500),
+	CDCE_FREQ_TABLE_ENTRY(5, 16875),
+	CDCE_FREQ_TABLE_ENTRY(5, 27000),
+	CDCE_FREQ_TABLE_ENTRY(5, 54000),
+	CDCE_FREQ_TABLE_ENTRY(5, 81000),
+};
+
+
+static struct cdce_output output_list[] = {
+	[1]	= { cdce_y1_freqs, ARRAY_SIZE(cdce_y1_freqs) },
+	[5]	= { cdce_y5_freqs, ARRAY_SIZE(cdce_y5_freqs) },
+};
+
+int cdce_set_rate(struct clk *clk, unsigned long rate)
+{
+	int i, ret = 0;
+	struct cdce_freq *freq_table = output_list[clk->lpsc].freq_table;
+	struct cdce_reg  *regs = NULL;
+
+	if (!cdce_i2c_client)
+		return -ENODEV;
+
+	if (!freq_table)
+		return -EINVAL;
+
+	for (i = 0; i < output_list[clk->lpsc].size; i++) {
+		if (freq_table[i].frequency == rate / 1000) {
+			regs = freq_table[i].reglist;
+			break;
+		}
+	}
+
+	if (!regs)
+		return -EINVAL;
+
+	for (i = 0; regs[i].addr; i++) {
+		ret = i2c_smbus_write_byte_data(cdce_i2c_client,
+					regs[i].addr | 0x80, regs[i].val);
+		if (ret)
+			return ret;
+	}
+
+	atomic_set(&clk->rate, rate);
+
+	return 0;
+}
+
+static int cdce_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	cdce_i2c_client = client;
+	return 0;
+}
+
+static int __devexit cdce_remove(struct i2c_client *client)
+{
+	cdce_i2c_client = NULL;
+	return 0;
+}
+
+static const struct i2c_device_id cdce_id[] = {
+	{"cdce949", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, cdce_id);
+
+static struct i2c_driver cdce_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "cdce949",
+	},
+	.probe		= cdce_probe,
+	.remove		= __devexit_p(cdce_remove),
+	.id_table	= cdce_id,
+};
+
+static int __init cdce_init(void)
+{
+	return i2c_add_driver(&cdce_driver);
+}
+subsys_initcall(cdce_init);
+
+static void __exit cdce_exit(void)
+{
+	i2c_del_driver(&cdce_driver);
+}
+module_exit(cdce_exit);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("CDCE949 clock synthesizer driver");
+MODULE_LICENSE("GPL v2");
diff --git a/arch/arm/mach-davinci/include/mach/cdce949.h b/arch/arm/mach-davinci/include/mach/cdce949.h
new file mode 100644
index 0000000..c73331f
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/cdce949.h
@@ -0,0 +1,19 @@ 
+/*
+ * TI CDCE949 off-chip clock synthesizer support
+ *
+ * 2009 (C) Texas Instruments, Inc. http://www.ti.com/
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+#ifndef _MACH_DAVINCI_CDCE949_H
+#define _MACH_DAVINCI_CDCE949_H
+
+#include <linux/clk.h>
+
+#include <mach/clock.h>
+
+int cdce_set_rate(struct clk *clk, unsigned long rate);
+
+#endif