| /* 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(); |
| } |