[ARM] 4430/1: davinci: clock control support

Support clock control driver for TI DaVinci SoC

Signed-off-by: Vladimir Barinov <[e-mail]>
Signed-off-by: Kevin Hilman <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/mach-davinci/Makefile

···
 #
 
 # Common objects
-obj-y 			:= time.o irq.o serial.o io.o id.o psc.o
+obj-y 			:= time.o irq.o clock.o serial.o io.o id.o psc.o
 
 # Board specific
 obj-$(CONFIG_MACH_DAVINCI_EVM)  += board-evm.o

arch/arm/mach-davinci/board-evm.c

···
 void __init davinci_psc_init(void);
 void __init davinci_irq_init(void);
 void __init davinci_map_common_io(void);
+void __init davinci_init_common_hw(void);
 
 /* NOR Flash base address set to CS0 by default */
 #define NOR_FLASH_PHYS 0x02000000
···
 
 static __init void davinci_evm_irq_init(void)
 {
+	davinci_init_common_hw();
 	davinci_irq_init();
 }
 

arch/arm/mach-davinci/clock.c

···
+/*
+ * TI DaVinci clock config file
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+
+#include <asm/arch/psc.h>
+#include "clock.h"
+
+/* PLL/Reset register offsets */
+#define PLLM		0x110
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+static DEFINE_SPINLOCK(clockfw_lock);
+
+static unsigned int commonrate;
+static unsigned int armrate;
+static unsigned int fixedrate = 27000000;	/* 27 MHZ */
+
+extern void davinci_psc_config(unsigned int domain, unsigned int id, char enable);
+
+/*
+ * Returns a clock. Note that we first try to use device id on the bus
+ * and clock name. If this fails, we try to use clock name only.
+ */
+struct clk *clk_get(struct device *dev, const char *id)
+{
+	struct clk *p, *clk = ERR_PTR(-ENOENT);
+	int idno;
+
+	if (dev == NULL || dev->bus != &platform_bus_type)
+		idno = -1;
+	else
+		idno = to_platform_device(dev)->id;
+
+	mutex_lock(&clocks_mutex);
+
+	list_for_each_entry(p, &clocks, node) {
+		if (p->id == idno &&
+		    strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
+			clk = p;
+			goto found;
+		}
+	}
+
+	list_for_each_entry(p, &clocks, node) {
+		if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
+			clk = p;
+			break;
+		}
+	}
+
+found:
+	mutex_unlock(&clocks_mutex);
+
+	return clk;
+}
+EXPORT_SYMBOL(clk_get);
+
+void clk_put(struct clk *clk)
+{
+	if (clk && !IS_ERR(clk))
+		module_put(clk->owner);
+}
+EXPORT_SYMBOL(clk_put);
+
+static int __clk_enable(struct clk *clk)
+{
+	if (clk->flags & ALWAYS_ENABLED)
+		return 0;
+
+	davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 1);
+	return 0;
+}
+
+static void __clk_disable(struct clk *clk)
+{
+	if (clk->usecount)
+		return;
+
+	davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 0);
+}
+
+int clk_enable(struct clk *clk)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	if (clk->usecount++ == 0) {
+		spin_lock_irqsave(&clockfw_lock, flags);
+		ret = __clk_enable(clk);
+		spin_unlock_irqrestore(&clockfw_lock, flags);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
+	if (clk->usecount > 0 && !(--clk->usecount)) {
+		spin_lock_irqsave(&clockfw_lock, flags);
+		__clk_disable(clk);
+		spin_unlock_irqrestore(&clockfw_lock, flags);
+	}
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	return *(clk->rate);
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	return *(clk->rate);
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	/* changing the clk rate is not supported */
+	return -EINVAL;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_register(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	mutex_lock(&clocks_mutex);
+	list_add(&clk->node, &clocks);
+	mutex_unlock(&clocks_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
+	mutex_lock(&clocks_mutex);
+	list_del(&clk->node);
+	mutex_unlock(&clocks_mutex);
+}
+EXPORT_SYMBOL(clk_unregister);
+
+static struct clk davinci_clks[] = {
+	{
+		.name = "ARMCLK",
+		.rate = &armrate,
+		.lpsc = -1,
+		.flags = ALWAYS_ENABLED,
+	},
+	{
+		.name = "UART",
+		.rate = &fixedrate,
+		.lpsc = DAVINCI_LPSC_UART0,
+	},
+	{
+		.name = "EMACCLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_EMAC_WRAPPER,
+	},
+	{
+		.name = "I2CCLK",
+		.rate = &fixedrate,
+		.lpsc = DAVINCI_LPSC_I2C,
+	},
+	{
+		.name = "IDECLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_ATA,
+	},
+	{
+		.name = "McBSPCLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_McBSP,
+	},
+	{
+		.name = "MMCSDCLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_MMC_SD,
+	},
+	{
+		.name = "SPICLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_SPI,
+	},
+	{
+		.name = "gpio",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_GPIO,
+	},
+	{
+		.name = "AEMIFCLK",
+		.rate = &commonrate,
+		.lpsc = DAVINCI_LPSC_AEMIF,
+		.usecount = 1,
+	}
+};
+
+int __init davinci_clk_init(void)
+{
+	struct clk *clkp;
+	int count = 0;
+	u32 pll_mult;
+
+	pll_mult = davinci_readl(DAVINCI_PLL_CNTRL0_BASE + PLLM);
+	commonrate = ((pll_mult + 1) * 27000000) / 6;
+	armrate = ((pll_mult + 1) * 27000000) / 2;
+
+	for (clkp = davinci_clks; count < ARRAY_SIZE(davinci_clks);
+	     count++, clkp++) {
+		clk_register(clkp);
+
+		/* Turn on clocks that have been enabled in the
+		 * table above */
+		if (clkp->usecount)
+			clk_enable(clkp);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
+{
+	return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return NULL;
+}
+
+static void davinci_ck_stop(struct seq_file *m, void *v)
+{
+}
+
+static int davinci_ck_show(struct seq_file *m, void *v)
+{
+	struct clk *cp;
+
+	list_for_each_entry(cp, &clocks, node)
+		seq_printf(m,"%s %d %d\n", cp->name, *(cp->rate), cp->usecount);
+
+	return 0;
+}
+
+static struct seq_operations davinci_ck_op = {
+	.start	= davinci_ck_start,
+	.next	= davinci_ck_next,
+	.stop	= davinci_ck_stop,
+	.show	= davinci_ck_show
+};
+
+static int davinci_ck_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &davinci_ck_op);
+}
+
+static struct file_operations proc_davinci_ck_operations = {
+	.open		= davinci_ck_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init davinci_ck_proc_init(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = create_proc_entry("davinci_clocks", 0, NULL);
+	if (entry)
+		entry->proc_fops = &proc_davinci_ck_operations;
+	return 0;
+
+}
+__initcall(davinci_ck_proc_init);
+#endif	/* CONFIG_DEBUG_PROC_FS */

arch/arm/mach-davinci/clock.h

···
+/*
+ * TI DaVinci clock definitions
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ *
+ * 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.
+ */
+
+#ifndef __ARCH_ARM_DAVINCI_CLOCK_H
+#define __ARCH_ARM_DAVINCI_CLOCK_H
+
+struct clk {
+	struct list_head	node;
+	struct module		*owner;
+	const char		*name;
+	unsigned int		*rate;
+	int			id;
+	__s8			usecount;
+	__u8			flags;
+	__u8			lpsc;
+};
+
+/* Clock flags */
+#define RATE_CKCTL		1
+#define RATE_FIXED		2
+#define RATE_PROPAGATES		4
+#define VIRTUAL_CLOCK		8
+#define ALWAYS_ENABLED		16
+#define ENABLE_REG_32BIT	32
+
+#endif

arch/arm/mach-davinci/io.c

···
 #include <asm/memory.h>
 
 #include <asm/mach/map.h>
+#include <asm/arch/clock.h>
 
 extern void davinci_check_revision(void);
 
···
 	 * IO space mapping must be initialized before we can do that.
 	 */
 	davinci_check_revision();
+}
+
+void __init davinci_init_common_hw(void)
+{
+	davinci_clk_init();
 }

include/asm-arm/arch-davinci/clock.h

···
+/*
+ * include/asm-arm/arch-davinci/clock.h
+ *
+ * Clock control driver for DaVinci - header file
+ *
+ * Authors: Vladimir Barinov <[e-mail]>
+ *
+ * 2007 (c) MontaVista Software, Inc. 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 __ASM_ARCH_DAVINCI_CLOCK_H
+#define __ASM_ARCH_DAVINCI_CLOCK_H
+
+struct clk;
+
+extern int clk_register(struct clk *clk);
+extern void clk_unregister(struct clk *clk);
+extern int davinci_clk_init(void);
+
+#endif