From e32f55d9dbffd2ca16e0bb4ea7156b56741b78cd Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 7 Jan 2009 23:14:39 +0800 Subject: [PATCH] Blackfin arch: rewrite get_sclk()/get_vco() rewrite get_sclk()/get_vco() based on the assumption sclk/vco never changes (since today it cannot) Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu --- arch/blackfin/kernel/setup.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/arch/blackfin/kernel/setup.c b/arch/blackfin/kernel/setup.c index 20d04a1bc86..b2a811347b6 100644 --- a/arch/blackfin/kernel/setup.c +++ b/arch/blackfin/kernel/setup.c @@ -956,17 +956,18 @@ static int __init early_init_clkin_hz(char *buf) early_param("clkin_hz=", early_init_clkin_hz); /* Get the voltage input multiplier */ -static u_long cached_vco_pll_ctl, cached_vco; static u_long get_vco(void) { - u_long msel; + static u_long cached_vco; + u_long msel, pll_ctl; - u_long pll_ctl = bfin_read_PLL_CTL(); - if (pll_ctl == cached_vco_pll_ctl) + /* The assumption here is that VCO never changes at runtime. + * If, someday, we support that, then we'll have to change this. + */ + if (cached_vco) return cached_vco; - else - cached_vco_pll_ctl = pll_ctl; + pll_ctl = bfin_read_PLL_CTL(); msel = (pll_ctl >> 9) & 0x3F; if (0 == msel) msel = 64; @@ -978,9 +979,9 @@ static u_long get_vco(void) } /* Get the Core clock */ -static u_long cached_cclk_pll_div, cached_cclk; u_long get_cclk(void) { + static u_long cached_cclk_pll_div, cached_cclk; u_long csel, ssel; if (bfin_read_PLL_STAT() & 0x1) @@ -1003,21 +1004,21 @@ u_long get_cclk(void) EXPORT_SYMBOL(get_cclk); /* Get the System clock */ -static u_long cached_sclk_pll_div, cached_sclk; u_long get_sclk(void) { + static u_long cached_sclk; u_long ssel; + /* The assumption here is that SCLK never changes at runtime. + * If, someday, we support that, then we'll have to change this. + */ + if (cached_sclk) + return cached_sclk; + if (bfin_read_PLL_STAT() & 0x1) return get_clkin_hz(); - ssel = bfin_read_PLL_DIV(); - if (ssel == cached_sclk_pll_div) - return cached_sclk; - else - cached_sclk_pll_div = ssel; - - ssel &= 0xf; + ssel = bfin_read_PLL_DIV() & 0xf; if (0 == ssel) { printk(KERN_WARNING "Invalid System Clock\n"); ssel = 1; -- 2.41.0