From c79504e73a0e84c4db7a2315dcdd6987b0c52566 Mon Sep 17 00:00:00 2001 From: Dinh Nguyen Date: Mon, 10 May 2010 13:45:58 -0500 Subject: [PATCH] mx5: change usb clock source from pll3 to pll2 For power management reasons, pll2 should be used to source the USBOH3 clock for mx51. PLL3 can be completely gated off when USB is not used. This patch applies to 2.6.34-rc7. Signed-off-by: Dinh Nguyen Signed-off-by: Sascha Hauer --- arch/arm/mach-mx5/clock-mx51.c | 43 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-mx5/clock-mx51.c b/arch/arm/mach-mx5/clock-mx51.c index dcca330..566cfda 100644 --- a/arch/arm/mach-mx5/clock-mx51.c +++ b/arch/arm/mach-mx5/clock-mx51.c @@ -36,6 +36,7 @@ static struct clk lp_apm_clk; static struct clk periph_apm_clk; static struct clk ahb_clk; static struct clk ipg_clk; +static struct clk usboh3_clk; #define MAX_DPLL_WAIT_TRIES 1000 /* 1000 * udelay(1) = 1ms */ @@ -569,6 +570,35 @@ static int _clk_uart_set_parent(struct clk *clk, struct clk *parent) return 0; } +static unsigned long clk_usboh3_get_rate(struct clk *clk) +{ + u32 reg, prediv, podf; + unsigned long parent_rate; + + parent_rate = clk_get_rate(clk->parent); + + reg = __raw_readl(MXC_CCM_CSCDR1); + prediv = ((reg & MXC_CCM_CSCDR1_USBOH3_CLK_PRED_MASK) >> + MXC_CCM_CSCDR1_USBOH3_CLK_PRED_OFFSET) + 1; + podf = ((reg & MXC_CCM_CSCDR1_USBOH3_CLK_PODF_MASK) >> + MXC_CCM_CSCDR1_USBOH3_CLK_PODF_OFFSET) + 1; + + return parent_rate / (prediv * podf); +} + +static int _clk_usboh3_set_parent(struct clk *clk, struct clk *parent) +{ + u32 reg, mux; + + mux = _get_mux(parent, &pll1_sw_clk, &pll2_sw_clk, &pll3_sw_clk, + &lp_apm_clk); + reg = __raw_readl(MXC_CCM_CSCMR1) & ~MXC_CCM_CSCMR1_USBOH3_CLK_SEL_MASK; + reg |= mux << MXC_CCM_CSCMR1_USBOH3_CLK_SEL_OFFSET; + __raw_writel(reg, MXC_CCM_CSCMR1); + + return 0; +} + static unsigned long get_high_reference_clock_rate(struct clk *clk) { return external_high_reference; @@ -690,6 +720,12 @@ static struct clk uart_root_clk = { .set_parent = _clk_uart_set_parent, }; +static struct clk usboh3_clk = { + .parent = &pll2_sw_clk, + .get_rate = clk_usboh3_get_rate, + .set_parent = _clk_usboh3_set_parent, +}; + static struct clk ahb_max_clk = { .parent = &ahb_clk, .enable_reg = MXC_CCM_CCGR0, @@ -761,10 +797,6 @@ DEFINE_CLOCK(gpt_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG9_OFFSET, DEFINE_CLOCK(gpt_ipg_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG10_OFFSET, NULL, NULL, &ipg_clk, NULL); -/* USB */ -DEFINE_CLOCK(usboh3_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG14_OFFSET, - NULL, NULL, &pll3_sw_clk, NULL); - /* FEC */ DEFINE_CLOCK(fec_clk, 0, MXC_CCM_CCGR2, MXC_CCM_CCGRx_CG12_OFFSET, NULL, NULL, &ipg_clk, NULL); @@ -826,6 +858,9 @@ int __init mx51_clocks_init(unsigned long ckil, unsigned long osc, clk_enable(&cpu_clk); clk_enable(&main_bus_clk); + /* set the usboh3_clk parent to pll2_sw_clk */ + clk_set_parent(&usboh3_clk, &pll2_sw_clk); + /* System timer */ mxc_timer_init(&gpt_clk, MX51_IO_ADDRESS(MX51_GPT1_BASE_ADDR), MX51_MXC_INT_GPT); -- 2.7.4