diff options
| -rw-r--r-- | arch/arm/plat-samsung/Kconfig | 5 | ||||
| -rw-r--r-- | arch/arm/plat-samsung/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/plat-samsung/clock-clksrc.c | 177 | ||||
| -rw-r--r-- | arch/arm/plat-samsung/include/plat/clock-clksrc.h | 75 |
4 files changed, 258 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig index 486a0d6301e7..e3ae68472ea7 100644 --- a/arch/arm/plat-samsung/Kconfig +++ b/arch/arm/plat-samsung/Kconfig @@ -13,5 +13,10 @@ config PLAT_SAMSUNG if PLAT_SAMSUNG +config SAMSUNG_CLKSRC + bool + help + Select the clock code for the clksrc implementation + used by newer systems such as the S3C64XX. endif diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile index 4478b9f7dc34..ce736ce468fd 100644 --- a/arch/arm/plat-samsung/Makefile +++ b/arch/arm/plat-samsung/Makefile @@ -9,3 +9,4 @@ obj-m := obj-n := dummy.o obj- := +obj-$(CONFIG_SAMSUNG_CLKSRC) += clock-clksrc.o diff --git a/arch/arm/plat-samsung/clock-clksrc.c b/arch/arm/plat-samsung/clock-clksrc.c new file mode 100644 index 000000000000..5872f0b62b7c --- /dev/null +++ b/arch/arm/plat-samsung/clock-clksrc.c @@ -0,0 +1,177 @@ +/* linux/arch/arm/plat-samsung/clock-clksrc.c + * + * Copyright 2008 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * http://armlinux.simtec.co.uk/ + * + * 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/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/sysdev.h> +#include <linux/io.h> + +#include <plat/clock.h> +#include <plat/clock-clksrc.h> +#include <plat/cpu-freq.h> + +static inline struct clksrc_clk *to_clksrc(struct clk *clk) +{ + return container_of(clk, struct clksrc_clk, clk); +} + +static inline u32 bit_mask(u32 shift, u32 nr_bits) +{ + u32 mask = 0xffffffff >> (32 - nr_bits); + + return mask << shift; +} + +static unsigned long s3c_getrate_clksrc(struct clk *clk) +{ + struct clksrc_clk *sclk = to_clksrc(clk); + unsigned long rate = clk_get_rate(clk->parent); + u32 clkdiv = __raw_readl(sclk->reg_div.reg); + u32 mask = bit_mask(sclk->reg_div.shift, sclk->reg_div.size); + + clkdiv &= mask; + clkdiv >>= sclk->reg_div.shift; + clkdiv++; + + rate /= clkdiv; + return rate; +} + +static int s3c_setrate_clksrc(struct clk *clk, unsigned long rate) +{ + struct clksrc_clk *sclk = to_clksrc(clk); + void __iomem *reg = sclk->reg_div.reg; + unsigned int div; + u32 mask = bit_mask(sclk->reg_div.shift, sclk->reg_div.size); + u32 val; + + rate = clk_round_rate(clk, rate); + div = clk_get_rate(clk->parent) / rate; + if (div > 16) + return -EINVAL; + + val = __raw_readl(reg); + val &= ~mask; + val |= (div - 1) << sclk->reg_div.shift; + __raw_writel(val, reg); + + return 0; +} + +static int s3c_setparent_clksrc(struct clk *clk, struct clk *parent) +{ + struct clksrc_clk *sclk = to_clksrc(clk); + struct clksrc_sources *srcs = sclk->sources; + u32 clksrc = __raw_readl(sclk->reg_src.reg); + u32 mask = bit_mask(sclk->reg_src.shift, sclk->reg_src.size); + int src_nr = -1; + int ptr; + + for (ptr = 0; ptr < srcs->nr_sources; ptr++) + if (srcs->sources[ptr] == parent) { + src_nr = ptr; + break; + } + + if (src_nr >= 0 && sclk->reg_src.reg) { + clk->parent = parent; + + clksrc &= ~mask; + clksrc |= src_nr << sclk->reg_src.shift; + + __raw_writel(clksrc, sclk->reg_src.reg); + return 0; + } + + return -EINVAL; +} + +static unsigned long s3c_roundrate_clksrc(struct clk *clk, + unsigned long rate) +{ + unsigned long parent_rate = clk_get_rate(clk->parent); + int div; + + if (rate >= parent_rate) + rate = parent_rate; + else { + div = parent_rate / rate; + if (parent_rate % rate) + div++; + + if (div == 0) + div = 1; + if (div > 16) + div = 16; + + rate = parent_rate / div; + } + + return rate; +} + +/* Clock initialisation code */ + +void __init_or_cpufreq s3c_set_clksrc(struct clksrc_clk *clk) +{ + struct clksrc_sources *srcs = clk->sources; + u32 mask = bit_mask(clk->reg_src.shift, clk->reg_src.size); + u32 clksrc = 0; + + if (clk->reg_src.reg) + clksrc = __raw_readl(clk->reg_src.reg); + + clksrc &= mask; + clksrc >>= clk->reg_src.shift; + + if (clksrc > srcs->nr_sources || !srcs->sources[clksrc]) { + printk(KERN_ERR "%s: bad source %d\n", + clk->clk.name, clksrc); + return; + } + + clk->clk.parent = srcs->sources[clksrc]; + + printk(KERN_INFO "%s: source is %s (%d), rate is %ld\n", + clk->clk.name, clk->clk.parent->name, clksrc, + clk_get_rate(&clk->clk)); +} + +void __init s3c_register_clksrc(struct clksrc_clk *clksrc, int size) +{ + int ret; + + for (; size > 0; size--, clksrc++) { + /* fill in the default functions */ + if (!clksrc->clk.set_parent) + clksrc->clk.set_parent = s3c_setparent_clksrc; + if (!clksrc->clk.get_rate) + clksrc->clk.get_rate = s3c_getrate_clksrc; + if (!clksrc->clk.set_rate) + clksrc->clk.set_rate = s3c_setrate_clksrc; + if (!clksrc->clk.round_rate) + clksrc->clk.round_rate = s3c_roundrate_clksrc; + + s3c_set_clksrc(clksrc); + + ret = s3c24xx_register_clock(&clksrc->clk); + + if (ret < 0) { + printk(KERN_ERR "%s: failed to register %s (%d)\n", + __func__, clksrc->clk.name, ret); + } + } +} diff --git a/arch/arm/plat-samsung/include/plat/clock-clksrc.h b/arch/arm/plat-samsung/include/plat/clock-clksrc.h new file mode 100644 index 000000000000..283dfa028757 --- /dev/null +++ b/arch/arm/plat-samsung/include/plat/clock-clksrc.h @@ -0,0 +1,75 @@ +/* linux/arch/arm/plat-samsung/include/plat/clock-clksrc.h + * + * Parts taken from arch/arm/plat-s3c64xx/clock.c + * Copyright 2008 Openmoko, Inc. + * Copyright 2008 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * http://armlinux.simtec.co.uk/ + * + * Copyright 2009 Ben Dooks <ben-linux@fluff.org> + * Copyright 2009 Harald Welte + * + * 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. +*/ + +/** + * struct clksrc_sources - list of sources for a given clock + * @sources: array of pointers to clocks + * @nr_sources: The size of @sources + */ +struct clksrc_sources { + unsigned int nr_sources; + struct clk **sources; +}; + +/** + * struct clksrc_reg - register definition for clock control bits + * @reg: pointer to the register in virtual memory. + * @shift: the shift in bits to where the bitfield is. + * @size: the size in bits of the bitfield. + * + * This specifies the size and position of the bits we are interested + * in within the register specified by @reg. + */ +struct clksrc_reg { + void __iomem *reg; + unsigned short shift; + unsigned short size; +}; + +/** + * struct clksrc_clk - class of clock for newer style samsung devices. + * @clk: the standard clock representation + * @sources: the sources for this clock + * @reg_src: the register definition for selecting the clock's source + * @reg_div: the register definition for the clock's output divisor + * + * This clock implements the features required by the newer SoCs where + * the standard clock block provides an input mux and a post-mux divisor + * to provide the periperhal's clock. + * + * The array of @sources provides the mapping of mux position to the + * clock, and @reg_src shows the code where to modify to change the mux + * position. The @reg_div defines how to change the divider settings on + * the output. + */ +struct clksrc_clk { + struct clk clk; + struct clksrc_sources *sources; + + struct clksrc_reg reg_src; + struct clksrc_reg reg_div; +}; + +extern void s3c_set_clksrc(struct clksrc_clk *clk); + +/** + * s3c_register_clksrc() register clocks from an array of clksrc clocks + * @srcs: The array of clocks to register + * @size: The size of the @srcs array. + * + * Initialise and register the array of clocks described by @srcs. + */ +extern void s3c_register_clksrc(struct clksrc_clk *srcs, int size); |