| /* linux/arch/arm/plat-s3c24xx/clock.c |
| * |
| * Copyright 2004-2005 Simtec Electronics |
| * Ben Dooks <ben@simtec.co.uk> |
| * |
| * S3C24XX Core clock control support |
| * |
| * Based on, and code from linux/arch/arm/mach-versatile/clock.c |
| ** |
| ** Copyright (C) 2004 ARM Limited. |
| ** Written by Deep Blue Solutions Limited. |
| * |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/list.h> |
| #include <linux/errno.h> |
| #include <linux/err.h> |
| #include <linux/platform_device.h> |
| #include <linux/sysdev.h> |
| #include <linux/interrupt.h> |
| #include <linux/ioport.h> |
| #include <linux/clk.h> |
| #include <linux/spinlock.h> |
| #include <linux/io.h> |
| |
| #include <mach/hardware.h> |
| #include <asm/irq.h> |
| |
| #include <plat/cpu-freq.h> |
| |
| #include <plat/clock.h> |
| #include <plat/cpu.h> |
| |
| /* clock information */ |
| |
| static LIST_HEAD(clocks); |
| |
| /* We originally used an mutex here, but some contexts (see resume) |
| * are calling functions such as clk_set_parent() with IRQs disabled |
| * causing an BUG to be triggered. |
| */ |
| DEFINE_SPINLOCK(clocks_lock); |
| |
| /* enable and disable calls for use with the clk struct */ |
| |
| static int clk_null_enable(struct clk *clk, int enable) |
| { |
| return 0; |
| } |
| |
| /* Clock API calls */ |
| |
| struct clk *clk_get(struct device *dev, const char *id) |
| { |
| struct clk *p; |
| struct clk *clk = ERR_PTR(-ENOENT); |
| int idno; |
| |
| if (dev == NULL || dev->bus != &platform_bus_type) |
| idno = -1; |
| else |
| idno = to_platform_device(dev)->id; |
| |
| spin_lock(&clocks_lock); |
| |
| list_for_each_entry(p, &clocks, list) { |
| if (p->id == idno && |
| strcmp(id, p->name) == 0 && |
| try_module_get(p->owner)) { |
| clk = p; |
| break; |
| } |
| } |
| |
| /* check for the case where a device was supplied, but the |
| * clock that was being searched for is not device specific */ |
| |
| if (IS_ERR(clk)) { |
| list_for_each_entry(p, &clocks, list) { |
| if (p->id == -1 && strcmp(id, p->name) == 0 && |
| try_module_get(p->owner)) { |
| clk = p; |
| break; |
| } |
| } |
| } |
| |
| spin_unlock(&clocks_lock); |
| return clk; |
| } |
| |
| void clk_put(struct clk *clk) |
| { |
| module_put(clk->owner); |
| } |
| |
| int clk_enable(struct clk *clk) |
| { |
| if (IS_ERR(clk) || clk == NULL) |
| return -EINVAL; |
| |
| clk_enable(clk->parent); |
| |
| spin_lock(&clocks_lock); |
| |
| if ((clk->usage++) == 0) |
| (clk->enable)(clk, 1); |
| |
| spin_unlock(&clocks_lock); |
| return 0; |
| } |
| |
| void clk_disable(struct clk *clk) |
| { |
| if (IS_ERR(clk) || clk == NULL) |
| return; |
| |
| spin_lock(&clocks_lock); |
| |
| if ((--clk->usage) == 0) |
| (clk->enable)(clk, 0); |
| |
| spin_unlock(&clocks_lock); |
| clk_disable(clk->parent); |
| } |
| |
| |
| unsigned long clk_get_rate(struct clk *clk) |
| { |
| if (IS_ERR(clk)) |
| return 0; |
| |
| if (clk->rate != 0) |
| return clk->rate; |
| |
| if (clk->ops != NULL && clk->ops->get_rate != NULL) |
| return (clk->ops->get_rate)(clk); |
| |
| if (clk->parent != NULL) |
| return clk_get_rate(clk->parent); |
| |
| return clk->rate; |
| } |
| |
| long clk_round_rate(struct clk *clk, unsigned long rate) |
| { |
| if (!IS_ERR(clk) && clk->ops && clk->ops->round_rate) |
| return (clk->ops->round_rate)(clk, rate); |
| |
| return rate; |
| } |
| |
| int clk_set_rate(struct clk *clk, unsigned long rate) |
| { |
| int ret; |
| |
| if (IS_ERR(clk)) |
| return -EINVAL; |
| |
| /* We do not default just do a clk->rate = rate as |
| * the clock may have been made this way by choice. |
| */ |
| |
| WARN_ON(clk->ops == NULL); |
| WARN_ON(clk->ops && clk->ops->set_rate == NULL); |
| |
| if (clk->ops == NULL || clk->ops->set_rate == NULL) |
| return -EINVAL; |
| |
| spin_lock(&clocks_lock); |
| ret = (clk->ops->set_rate)(clk, rate); |
| spin_unlock(&clocks_lock); |
| |
| return ret; |
| } |
| |
| struct clk *clk_get_parent(struct clk *clk) |
| { |
| return clk->parent; |
| } |
| |
| int clk_set_parent(struct clk *clk, struct clk *parent) |
| { |
| int ret = 0; |
| |
| if (IS_ERR(clk)) |
| return -EINVAL; |
| |
| spin_lock(&clocks_lock); |
| |
| if (clk->ops && clk->ops->set_parent) |
| ret = (clk->ops->set_parent)(clk, parent); |
| |
| spin_unlock(&clocks_lock); |
| |
| return ret; |
| } |
| |
| EXPORT_SYMBOL(clk_get); |
| EXPORT_SYMBOL(clk_put); |
| EXPORT_SYMBOL(clk_enable); |
| EXPORT_SYMBOL(clk_disable); |
| EXPORT_SYMBOL(clk_get_rate); |
| EXPORT_SYMBOL(clk_round_rate); |
| EXPORT_SYMBOL(clk_set_rate); |
| EXPORT_SYMBOL(clk_get_parent); |
| EXPORT_SYMBOL(clk_set_parent); |
| |
| /* base clocks */ |
| |
| int clk_default_setrate(struct clk *clk, unsigned long rate) |
| { |
| clk->rate = rate; |
| return 0; |
| } |
| |
| struct clk_ops clk_ops_def_setrate = { |
| .set_rate = clk_default_setrate, |
| }; |
| |
| struct clk clk_xtal = { |
| .name = "xtal", |
| .id = -1, |
| .rate = 0, |
| .parent = NULL, |
| .ctrlbit = 0, |
| }; |
| |
| struct clk clk_ext = { |
| .name = "ext", |
| .id = -1, |
| }; |
| |
| struct clk clk_epll = { |
| .name = "epll", |
| .id = -1, |
| }; |
| |
| struct clk clk_mpll = { |
| .name = "mpll", |
| .id = -1, |
| .ops = &clk_ops_def_setrate, |
| }; |
| |
| struct clk clk_upll = { |
| .name = "upll", |
| .id = -1, |
| .parent = NULL, |
| .ctrlbit = 0, |
| }; |
| |
| struct clk clk_f = { |
| .name = "fclk", |
| .id = -1, |
| .rate = 0, |
| .parent = &clk_mpll, |
| .ctrlbit = 0, |
| }; |
| |
| struct clk clk_h = { |
| .name = "hclk", |
| .id = -1, |
| .rate = 0, |
| .parent = NULL, |
| .ctrlbit = 0, |
| .ops = &clk_ops_def_setrate, |
| }; |
| |
| struct clk clk_p = { |
| .name = "pclk", |
| .id = -1, |
| .rate = 0, |
| .parent = NULL, |
| .ctrlbit = 0, |
| .ops = &clk_ops_def_setrate, |
| }; |
| |
| struct clk clk_usb_bus = { |
| .name = "usb-bus", |
| .id = -1, |
| .rate = 0, |
| .parent = &clk_upll, |
| }; |
| |
| |
| struct clk s3c24xx_uclk = { |
| .name = "uclk", |
| .id = -1, |
| }; |
| |
| /* initialise the clock system */ |
| |
| /** |
| * s3c24xx_register_clock() - register a clock |
| * @clk: The clock to register |
| * |
| * Add the specified clock to the list of clocks known by the system. |
| */ |
| int s3c24xx_register_clock(struct clk *clk) |
| { |
| if (clk->enable == NULL) |
| clk->enable = clk_null_enable; |
| |
| /* add to the list of available clocks */ |
| |
| /* Quick check to see if this clock has already been registered. */ |
| BUG_ON(clk->list.prev != clk->list.next); |
| |
| spin_lock(&clocks_lock); |
| list_add(&clk->list, &clocks); |
| spin_unlock(&clocks_lock); |
| |
| return 0; |
| } |
| |
| /** |
| * s3c24xx_register_clocks() - register an array of clock pointers |
| * @clks: Pointer to an array of struct clk pointers |
| * @nr_clks: The number of clocks in the @clks array. |
| * |
| * Call s3c24xx_register_clock() for all the clock pointers contained |
| * in the @clks list. Returns the number of failures. |
| */ |
| int s3c24xx_register_clocks(struct clk **clks, int nr_clks) |
| { |
| int fails = 0; |
| |
| for (; nr_clks > 0; nr_clks--, clks++) { |
| if (s3c24xx_register_clock(*clks) < 0) { |
| struct clk *clk = *clks; |
| printk(KERN_ERR "%s: failed to register %p: %s\n", |
| __func__, clk, clk->name); |
| fails++; |
| } |
| } |
| |
| return fails; |
| } |
| |
| /** |
| * s3c_register_clocks() - register an array of clocks |
| * @clkp: Pointer to the first clock in the array. |
| * @nr_clks: Number of clocks to register. |
| * |
| * Call s3c24xx_register_clock() on the @clkp array given, printing an |
| * error if it fails to register the clock (unlikely). |
| */ |
| void __init s3c_register_clocks(struct clk *clkp, int nr_clks) |
| { |
| int ret; |
| |
| for (; nr_clks > 0; nr_clks--, clkp++) { |
| ret = s3c24xx_register_clock(clkp); |
| |
| if (ret < 0) { |
| printk(KERN_ERR "Failed to register clock %s (%d)\n", |
| clkp->name, ret); |
| } |
| } |
| } |
| |
| /** |
| * s3c_disable_clocks() - disable an array of clocks |
| * @clkp: Pointer to the first clock in the array. |
| * @nr_clks: Number of clocks to register. |
| * |
| * for internal use only at initialisation time. disable the clocks in the |
| * @clkp array. |
| */ |
| |
| void __init s3c_disable_clocks(struct clk *clkp, int nr_clks) |
| { |
| for (; nr_clks > 0; nr_clks--, clkp++) |
| (clkp->enable)(clkp, 0); |
| } |
| |
| /* initalise all the clocks */ |
| |
| int __init s3c24xx_register_baseclocks(unsigned long xtal) |
| { |
| printk(KERN_INFO "S3C24XX Clocks, Copyright 2004 Simtec Electronics\n"); |
| |
| clk_xtal.rate = xtal; |
| |
| /* register our clocks */ |
| |
| if (s3c24xx_register_clock(&clk_xtal) < 0) |
| printk(KERN_ERR "failed to register master xtal\n"); |
| |
| if (s3c24xx_register_clock(&clk_mpll) < 0) |
| printk(KERN_ERR "failed to register mpll clock\n"); |
| |
| if (s3c24xx_register_clock(&clk_upll) < 0) |
| printk(KERN_ERR "failed to register upll clock\n"); |
| |
| if (s3c24xx_register_clock(&clk_f) < 0) |
| printk(KERN_ERR "failed to register cpu fclk\n"); |
| |
| if (s3c24xx_register_clock(&clk_h) < 0) |
| printk(KERN_ERR "failed to register cpu hclk\n"); |
| |
| if (s3c24xx_register_clock(&clk_p) < 0) |
| printk(KERN_ERR "failed to register cpu pclk\n"); |
| |
| return 0; |
| } |
| |