diff options
Diffstat (limited to 'arch/arm/mach-lpc32xx/clock.c')
| -rw-r--r-- | arch/arm/mach-lpc32xx/clock.c | 87 |
1 files changed, 63 insertions, 24 deletions
diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c index f55c772d1816..b7ef51119d37 100644 --- a/arch/arm/mach-lpc32xx/clock.c +++ b/arch/arm/mach-lpc32xx/clock.c @@ -87,6 +87,7 @@ #include <linux/list.h> #include <linux/errno.h> #include <linux/device.h> +#include <linux/delay.h> #include <linux/err.h> #include <linux/clk.h> #include <linux/amba/bus.h> @@ -100,6 +101,8 @@ static DEFINE_SPINLOCK(global_clkregs_lock); +static int usb_pll_enable, usb_pll_valid; + static struct clk clk_armpll; static struct clk clk_usbpll; @@ -384,30 +387,62 @@ static u32 local_clk_usbpll_setup(struct clk_pll_setup *pHCLKPllSetup) static int local_usbpll_enable(struct clk *clk, int enable) { u32 reg; - int ret = -ENODEV; - unsigned long timeout = jiffies + msecs_to_jiffies(10); + int ret = 0; + unsigned long timeout = jiffies + msecs_to_jiffies(20); reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL); - if (enable == 0) { - reg &= ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN1 | - LPC32XX_CLKPWR_USBCTRL_CLK_EN2); - __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); - } else if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP) { + __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN2 | + LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP), + LPC32XX_CLKPWR_USB_CTRL); + __raw_writel(reg & ~LPC32XX_CLKPWR_USBCTRL_CLK_EN1, + LPC32XX_CLKPWR_USB_CTRL); + + if (enable && usb_pll_valid && usb_pll_enable) { + ret = -ENODEV; + /* + * If the PLL rate has been previously set, then the rate + * in the PLL register is valid and can be enabled here. + * Otherwise, it needs to be enabled as part of setrate. + */ + + /* + * Gate clock into PLL + */ reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN1; __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); - /* Wait for PLL lock */ + /* + * Enable PLL + */ + reg |= LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP; + __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); + + /* + * Wait for PLL to lock + */ while (time_before(jiffies, timeout) && (ret == -ENODEV)) { reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL); if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_STS) ret = 0; + else + udelay(10); } + /* + * Gate clock from PLL if PLL is locked + */ if (ret == 0) { - reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN2; - __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); + __raw_writel(reg | LPC32XX_CLKPWR_USBCTRL_CLK_EN2, + LPC32XX_CLKPWR_USB_CTRL); + } else { + __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN1 | + LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP), + LPC32XX_CLKPWR_USB_CTRL); } + } else if ((enable == 0) && usb_pll_valid && usb_pll_enable) { + usb_pll_valid = 0; + usb_pll_enable = 0; } return ret; @@ -425,7 +460,7 @@ static unsigned long local_usbpll_round_rate(struct clk *clk, */ rate = rate * 1000; - clkin = clk->parent->rate; + clkin = clk->get_rate(clk); usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) & LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1; clkin = clkin / usbdiv; @@ -439,7 +474,8 @@ static unsigned long local_usbpll_round_rate(struct clk *clk, static int local_usbpll_set_rate(struct clk *clk, unsigned long rate) { - u32 clkin, reg, usbdiv; + int ret = -ENODEV; + u32 clkin, usbdiv; struct clk_pll_setup pllsetup; /* @@ -448,7 +484,7 @@ static int local_usbpll_set_rate(struct clk *clk, unsigned long rate) */ rate = rate * 1000; - clkin = clk->get_rate(clk); + clkin = clk->get_rate(clk->parent); usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) & LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1; clkin = clkin / usbdiv; @@ -457,22 +493,25 @@ static int local_usbpll_set_rate(struct clk *clk, unsigned long rate) if (local_clk_find_pll_cfg(clkin, rate, &pllsetup) == 0) return -EINVAL; + /* + * Disable PLL clocks during PLL change + */ local_usbpll_enable(clk, 0); - - reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL); - reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN1; - __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); - - pllsetup.analog_on = 1; + pllsetup.analog_on = 0; local_clk_usbpll_setup(&pllsetup); - clk->rate = clk_check_pll_setup(clkin, &pllsetup); + /* + * Start USB PLL and check PLL status + */ + + usb_pll_valid = 1; + usb_pll_enable = 1; - reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL); - reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN2; - __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); + ret = local_usbpll_enable(clk, 1); + if (ret >= 0) + clk->rate = clk_check_pll_setup(clkin, &pllsetup); - return 0; + return ret; } static struct clk clk_usbpll = { |