diff options
Diffstat (limited to 'arch/arm/mach-s3c2443/clock.c')
| -rw-r--r-- | arch/arm/mach-s3c2443/clock.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2443/clock.c b/arch/arm/mach-s3c2443/clock.c new file mode 100644 index 00000000..f4ec6d57 --- /dev/null +++ b/arch/arm/mach-s3c2443/clock.c @@ -0,0 +1,376 @@ +/* linux/arch/arm/mach-s3c2443/clock.c + * + * Copyright (c) 2007, 2010 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2443 Clock control support + * + * 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/sysdev.h> +#include <linux/clk.h> +#include <linux/mutex.h> +#include <linux/serial_core.h> +#include <linux/io.h> + +#include <asm/mach/map.h> + +#include <mach/hardware.h> + +#include <mach/regs-s3c2443-clock.h> + +#include <plat/cpu-freq.h> + +#include <plat/s3c2443.h> +#include <plat/clock.h> +#include <plat/clock-clksrc.h> +#include <plat/cpu.h> + +/* We currently have to assume that the system is running + * from the XTPll input, and that all ***REFCLKs are being + * fed from it, as we cannot read the state of OM[4] from + * software. + * + * It would be possible for each board initialisation to + * set the correct muxing at initialisation +*/ + +/* clock selections */ + +static struct clk clk_i2s_ext = { + .name = "i2s-ext", + .id = -1, +}; + +/* armdiv + * + * this clock is sourced from msysclk and can have a number of + * divider values applied to it to then be fed into armclk. +*/ + +/* armdiv divisor table */ + +static unsigned int armdiv[16] = { + [S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 1, + [S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 2, + [S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 3, + [S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 4, + [S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 6, + [S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 8, + [S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 12, + [S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 16, +}; + +static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0) +{ + clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK; + + return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]; +} + +static unsigned long s3c2443_armclk_roundrate(struct clk *clk, + unsigned long rate) +{ + unsigned long parent = clk_get_rate(clk->parent); + unsigned long calc; + unsigned best = 256; /* bigger than any value */ + unsigned div; + int ptr; + + for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) { + div = armdiv[ptr]; + calc = parent / div; + if (calc <= rate && div < best) + best = div; + } + + return parent / best; +} + +static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate) +{ + unsigned long parent = clk_get_rate(clk->parent); + unsigned long calc; + unsigned div; + unsigned best = 256; /* bigger than any value */ + int ptr; + int val = -1; + + for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) { + div = armdiv[ptr]; + calc = parent / div; + if (calc <= rate && div < best) { + best = div; + val = ptr; + } + } + + if (val >= 0) { + unsigned long clkcon0; + + clkcon0 = __raw_readl(S3C2443_CLKDIV0); + clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK; + clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT; + __raw_writel(clkcon0, S3C2443_CLKDIV0); + } + + return (val == -1) ? -EINVAL : 0; +} + +static struct clk clk_armdiv = { + .name = "armdiv", + .id = -1, + .parent = &clk_msysclk.clk, + .ops = &(struct clk_ops) { + .round_rate = s3c2443_armclk_roundrate, + .set_rate = s3c2443_armclk_setrate, + }, +}; + +/* armclk + * + * this is the clock fed into the ARM core itself, from armdiv or from hclk. + */ + +static struct clk *clk_arm_sources[] = { + [0] = &clk_armdiv, + [1] = &clk_h, +}; + +static struct clksrc_clk clk_arm = { + .clk = { + .name = "armclk", + .id = -1, + }, + .sources = &(struct clksrc_sources) { + .sources = clk_arm_sources, + .nr_sources = ARRAY_SIZE(clk_arm_sources), + }, + .reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 }, +}; + +/* hsspi + * + * high-speed spi clock, sourced from esysclk +*/ + +static struct clksrc_clk clk_hsspi = { + .clk = { + .name = "hsspi", + .id = -1, + .parent = &clk_esysclk.clk, + .ctrlbit = S3C2443_SCLKCON_HSSPICLK, + .enable = s3c2443_clkcon_enable_s, + }, + .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 }, +}; + + +/* clk_hsmcc_div + * + * this clock is sourced from epll, and is fed through a divider, + * to a mux controlled by sclkcon where either it or a extclk can + * be fed to the hsmmc block +*/ + +static struct clksrc_clk clk_hsmmc_div = { + .clk = { + .name = "hsmmc-div", + .id = 1, + .parent = &clk_esysclk.clk, + }, + .reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 }, +}; + +static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent) +{ + unsigned long clksrc = __raw_readl(S3C2443_SCLKCON); + + clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT | + S3C2443_SCLKCON_HSMMCCLK_EPLL); + + if (parent == &clk_epll) + clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL; + else if (parent == &clk_ext) + clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT; + else + return -EINVAL; + + if (clk->usage > 0) { + __raw_writel(clksrc, S3C2443_SCLKCON); + } + + clk->parent = parent; + return 0; +} + +static int s3c2443_enable_hsmmc(struct clk *clk, int enable) +{ + return s3c2443_setparent_hsmmc(clk, clk->parent); +} + +static struct clk clk_hsmmc = { + .name = "hsmmc-if", + .id = 1, + .parent = &clk_hsmmc_div.clk, + .enable = s3c2443_enable_hsmmc, + .ops = &(struct clk_ops) { + .set_parent = s3c2443_setparent_hsmmc, + }, +}; + +/* i2s_eplldiv + * + * This clock is the output from the I2S divisor of ESYSCLK, and is separate + * from the mux that comes after it (cannot merge into one single clock) +*/ + +static struct clksrc_clk clk_i2s_eplldiv = { + .clk = { + .name = "i2s-eplldiv", + .id = -1, + .parent = &clk_esysclk.clk, + }, + .reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, }, +}; + +/* i2s-ref + * + * i2s bus reference clock, selectable from external, esysclk or epllref + * + * Note, this used to be two clocks, but was compressed into one. +*/ + +struct clk *clk_i2s_srclist[] = { + [0] = &clk_i2s_eplldiv.clk, + [1] = &clk_i2s_ext, + [2] = &clk_epllref.clk, + [3] = &clk_epllref.clk, +}; + +static struct clksrc_clk clk_i2s = { + .clk = { + .name = "i2s-if", + .id = -1, + .ctrlbit = S3C2443_SCLKCON_I2SCLK, + .enable = s3c2443_clkcon_enable_s, + + }, + .sources = &(struct clksrc_sources) { + .sources = clk_i2s_srclist, + .nr_sources = ARRAY_SIZE(clk_i2s_srclist), + }, + .reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 }, +}; + +/* standard clock definitions */ + +static struct clk init_clocks_off[] = { + { + .name = "sdi", + .id = -1, + .parent = &clk_p, + .enable = s3c2443_clkcon_enable_p, + .ctrlbit = S3C2443_PCLKCON_SDI, + }, { + .name = "iis", + .id = -1, + .parent = &clk_p, + .enable = s3c2443_clkcon_enable_p, + .ctrlbit = S3C2443_PCLKCON_IIS, + }, { + .name = "spi", + .id = 0, + .parent = &clk_p, + .enable = s3c2443_clkcon_enable_p, + .ctrlbit = S3C2443_PCLKCON_SPI0, + }, { + .name = "spi", + .id = 1, + .parent = &clk_p, + .enable = s3c2443_clkcon_enable_p, + .ctrlbit = S3C2443_PCLKCON_SPI1, + } +}; + +static struct clk init_clocks[] = { +}; + +/* clocks to add straight away */ + +static struct clksrc_clk *clksrcs[] __initdata = { + &clk_arm, + &clk_i2s_eplldiv, + &clk_i2s, + &clk_hsspi, + &clk_hsmmc_div, +}; + +static struct clk *clks[] __initdata = { + &clk_hsmmc, + &clk_armdiv, +}; + +void __init_or_cpufreq s3c2443_setup_clocks(void) +{ + s3c2443_common_setup_clocks(s3c2443_get_mpll, s3c2443_fclk_div); +} + +void __init s3c2443_init_clocks(int xtal) +{ + unsigned long epllcon = __raw_readl(S3C2443_EPLLCON); + int ptr; + + clk_epll.rate = s3c2443_get_epll(epllcon, xtal); + clk_epll.parent = &clk_epllref.clk; + + s3c2443_common_init_clocks(xtal, s3c2443_get_mpll, s3c2443_fclk_div); + + s3c2443_setup_clocks(); + + s3c24xx_register_clocks(clks, ARRAY_SIZE(clks)); + + for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++) + s3c_register_clksrc(clksrcs[ptr], 1); + + /* register clocks from clock array */ + + s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks)); + + /* We must be careful disabling the clocks we are not intending to + * be using at boot time, as subsystems such as the LCD which do + * their own DMA requests to the bus can cause the system to lockup + * if they where in the middle of requesting bus access. + * + * Disabling the LCD clock if the LCD is active is very dangerous, + * and therefore the bootloader should be careful to not enable + * the LCD clock if it is not needed. + */ + + /* install (and disable) the clocks we do not need immediately */ + + s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off)); + s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off)); + + s3c_pwmclk_init(); +} |