From 496a3f0927197ca155a604478bf6e7db3eca3bbd Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Sat, 2 May 2009 13:48:53 +0100 Subject: [ARM] S3C64XX: Add ARM clock Add ARM clock to provide 'arm' from the APLL to the ARM core. Signed-off-by: Ben Dooks --- arch/arm/plat-s3c64xx/include/plat/s3c6400.h | 2 +- arch/arm/plat-s3c64xx/s3c6400-clock.c | 76 +++++++++++++++++++++++++++- 2 files changed, 76 insertions(+), 2 deletions(-) (limited to 'arch/arm/plat-s3c64xx') diff --git a/arch/arm/plat-s3c64xx/include/plat/s3c6400.h b/arch/arm/plat-s3c64xx/include/plat/s3c6400.h index e12296666d46..11f2e1e119b0 100644 --- a/arch/arm/plat-s3c64xx/include/plat/s3c6400.h +++ b/arch/arm/plat-s3c64xx/include/plat/s3c6400.h @@ -15,7 +15,7 @@ /* Common init code for S3C6400 related SoCs */ extern void s3c6400_common_init_uarts(struct s3c2410_uartcfg *cfg, int no); -extern void s3c6400_register_clocks(void); +extern void s3c6400_register_clocks(unsigned armclk_divlimit); extern void s3c6400_setup_clocks(void); #ifdef CONFIG_CPU_S3C6400 diff --git a/arch/arm/plat-s3c64xx/s3c6400-clock.c b/arch/arm/plat-s3c64xx/s3c6400-clock.c index 96fa9ea4d5bc..1debc1f9f987 100644 --- a/arch/arm/plat-s3c64xx/s3c6400-clock.c +++ b/arch/arm/plat-s3c64xx/s3c6400-clock.c @@ -133,6 +133,65 @@ static struct clksrc_clk clk_mout_mpll = { .sources = &clk_src_mpll, }; +static unsigned int armclk_mask; + +static unsigned long s3c64xx_clk_arm_get_rate(struct clk *clk) +{ + unsigned long rate = clk_get_rate(clk->parent); + u32 clkdiv; + + /* divisor mask starts at bit0, so no need to shift */ + clkdiv = __raw_readl(S3C_CLK_DIV0) & armclk_mask; + + return rate / (clkdiv + 1); +} + +static unsigned long s3c64xx_clk_arm_round_rate(struct clk *clk, + unsigned long rate) +{ + unsigned long parent = clk_get_rate(clk->parent); + u32 div; + + if (parent < rate) + return rate; + + div = (parent / rate) - 1; + if (div > armclk_mask) + div = armclk_mask; + + return parent / (div + 1); +} + +static int s3c64xx_clk_arm_set_rate(struct clk *clk, unsigned long rate) +{ + unsigned long parent = clk_get_rate(clk->parent); + u32 div; + u32 val; + + if (rate < parent / (armclk_mask + 1)) + return -EINVAL; + + rate = clk_round_rate(clk, rate); + div = clk_get_rate(clk->parent) / rate; + + val = __raw_readl(S3C_CLK_DIV0); + val &= armclk_mask; + val |= (div - 1); + __raw_writel(val, S3C_CLK_DIV0); + + return 0; + +} + +static struct clk clk_arm = { + .name = "armclk", + .id = -1, + .parent = &clk_mout_apll.clk, + .get_rate = s3c64xx_clk_arm_get_rate, + .set_rate = s3c64xx_clk_arm_set_rate, + .round_rate = s3c64xx_clk_arm_round_rate, +}; + static unsigned long s3c64xx_clk_doutmpll_get_rate(struct clk *clk) { unsigned long rate = clk_get_rate(clk->parent); @@ -665,14 +724,29 @@ static struct clk *clks[] __initdata = { &clk_audio1.clk, &clk_irda.clk, &clk_camif.clk, + &clk_arm, }; -void __init s3c6400_register_clocks(void) +/** + * s3c6400_register_clocks - register clocks for s3c6400 and above + * @armclk_divlimit: Divisor mask for ARMCLK + * + * Register the clocks for the S3C6400 and above SoC range, such + * as ARMCLK and the clocks which have divider chains attached. + * + * This call does not setup the clocks, which is left to the + * s3c6400_setup_clocks() call which may be needed by the cpufreq + * or resume code to re-set the clocks if the bootloader has changed + * them. + */ +void __init s3c6400_register_clocks(unsigned armclk_divlimit) { struct clk *clkp; int ret; int ptr; + armclk_mask = armclk_divlimit; + for (ptr = 0; ptr < ARRAY_SIZE(clks); ptr++) { clkp = clks[ptr]; ret = s3c24xx_register_clock(clkp); -- cgit v1.2.3-59-g8ed1b