From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/arm/plat-samsung/clock.c | 541 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 541 insertions(+) create mode 100644 arch/arm/plat-samsung/clock.c (limited to 'arch/arm/plat-samsung/clock.c') diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c new file mode 100644 index 00000000..77289282 --- /dev/null +++ b/arch/arm/plat-samsung/clock.c @@ -0,0 +1,541 @@ +/* linux/arch/arm/plat-s3c24xx/clock.c + * + * Copyright 2004-2005 Simtec Electronics + * Ben Dooks + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#if defined(CONFIG_DEBUG_FS) +#include +#endif + +#include +#include + +#include + +#include +#include + +#include +#include /* for s3c24xx_uart_devs */ + +/* 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; +} + +static int dev_is_s3c_uart(struct device *dev) +{ + struct platform_device **pdev = s3c24xx_uart_devs; + int i; + for (i = 0; i < ARRAY_SIZE(s3c24xx_uart_devs); i++, pdev++) + if (*pdev && dev == &(*pdev)->dev) + return 1; + return 0; +} + +/* + * Serial drivers call get_clock() very early, before platform bus + * has been set up, this requires a special check to let them get + * a proper clock + */ + +static int dev_is_platform_device(struct device *dev) +{ + return dev->bus == &platform_bus_type || + (dev->bus == NULL && dev_is_s3c_uart(dev)); +} + +/* 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_is_platform_device(dev)) + 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); +} + +/* initialise 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; +} + +#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) +/* debugfs support to trace clock tree hierarchy and attributes */ + +static struct dentry *clk_debugfs_root; + +static int clk_debugfs_register_one(struct clk *c) +{ + int err; + struct dentry *d, *child, *child_tmp; + struct clk *pa = c->parent; + char s[255]; + char *p = s; + + p += sprintf(p, "%s", c->name); + + if (c->id >= 0) + sprintf(p, ":%d", c->id); + + d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root); + if (!d) + return -ENOMEM; + + c->dent = d; + + d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usage); + if (!d) { + err = -ENOMEM; + goto err_out; + } + + d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate); + if (!d) { + err = -ENOMEM; + goto err_out; + } + return 0; + +err_out: + d = c->dent; + list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child) + debugfs_remove(child); + debugfs_remove(c->dent); + return err; +} + +static int clk_debugfs_register(struct clk *c) +{ + int err; + struct clk *pa = c->parent; + + if (pa && !pa->dent) { + err = clk_debugfs_register(pa); + if (err) + return err; + } + + if (!c->dent) { + err = clk_debugfs_register_one(c); + if (err) + return err; + } + return 0; +} + +static int __init clk_debugfs_init(void) +{ + struct clk *c; + struct dentry *d; + int err; + + d = debugfs_create_dir("clock", NULL); + if (!d) + return -ENOMEM; + clk_debugfs_root = d; + + list_for_each_entry(c, &clocks, list) { + err = clk_debugfs_register(c); + if (err) + goto err_out; + } + return 0; + +err_out: + debugfs_remove_recursive(clk_debugfs_root); + return err; +} +late_initcall(clk_debugfs_init); + +#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */ -- cgit v1.2.3