diff options
Diffstat (limited to 'arch/arm/mach-ep93xx/clock.c')
| -rw-r--r-- | arch/arm/mach-ep93xx/clock.c | 216 |
1 files changed, 187 insertions, 29 deletions
diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c index 3dd0e2a2309..1d0f9d8aff2 100644 --- a/arch/arm/mach-ep93xx/clock.c +++ b/arch/arm/mach-ep93xx/clock.c @@ -16,13 +16,16 @@ #include <linux/module.h> #include <linux/string.h> #include <linux/io.h> +#include <linux/spinlock.h> + +#include <mach/hardware.h> #include <asm/clkdev.h> #include <asm/div64.h> -#include <mach/hardware.h> struct clk { + struct clk *parent; unsigned long rate; int users; int sw_locked; @@ -37,91 +40,130 @@ struct clk { static unsigned long get_uart_rate(struct clk *clk); static int set_keytchclk_rate(struct clk *clk, unsigned long rate); +static int set_div_rate(struct clk *clk, unsigned long rate); +static struct clk clk_xtali = { + .rate = EP93XX_EXT_CLK_RATE, +}; static struct clk clk_uart1 = { + .parent = &clk_xtali, .sw_locked = 1, .enable_reg = EP93XX_SYSCON_DEVCFG, .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN, .get_rate = get_uart_rate, }; static struct clk clk_uart2 = { + .parent = &clk_xtali, .sw_locked = 1, .enable_reg = EP93XX_SYSCON_DEVCFG, .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN, .get_rate = get_uart_rate, }; static struct clk clk_uart3 = { + .parent = &clk_xtali, .sw_locked = 1, .enable_reg = EP93XX_SYSCON_DEVCFG, .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN, .get_rate = get_uart_rate, }; -static struct clk clk_pll1; -static struct clk clk_f; -static struct clk clk_h; -static struct clk clk_p; -static struct clk clk_pll2; +static struct clk clk_pll1 = { + .parent = &clk_xtali, +}; +static struct clk clk_f = { + .parent = &clk_pll1, +}; +static struct clk clk_h = { + .parent = &clk_pll1, +}; +static struct clk clk_p = { + .parent = &clk_pll1, +}; +static struct clk clk_pll2 = { + .parent = &clk_xtali, +}; static struct clk clk_usb_host = { + .parent = &clk_pll2, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN, }; static struct clk clk_keypad = { + .parent = &clk_xtali, .sw_locked = 1, .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV, .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN, .set_rate = set_keytchclk_rate, }; static struct clk clk_pwm = { + .parent = &clk_xtali, .rate = EP93XX_EXT_CLK_RATE, }; +static struct clk clk_video = { + .sw_locked = 1, + .enable_reg = EP93XX_SYSCON_VIDCLKDIV, + .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE, + .set_rate = set_div_rate, +}; + /* DMA Clocks */ static struct clk clk_m2p0 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0, }; static struct clk clk_m2p1 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1, }; static struct clk clk_m2p2 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2, }; static struct clk clk_m2p3 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3, }; static struct clk clk_m2p4 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4, }; static struct clk clk_m2p5 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5, }; static struct clk clk_m2p6 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6, }; static struct clk clk_m2p7 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7, }; static struct clk clk_m2p8 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8, }; static struct clk clk_m2p9 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9, }; static struct clk clk_m2m0 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0, }; static struct clk clk_m2m1 = { + .parent = &clk_h, .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1, }; @@ -130,6 +172,7 @@ static struct clk clk_m2m1 = { { .dev_id = dev, .con_id = con, .clk = ck } static struct clk_lookup clocks[] = { + INIT_CK(NULL, "xtali", &clk_xtali), INIT_CK("apb:uart1", NULL, &clk_uart1), INIT_CK("apb:uart2", NULL, &clk_uart2), INIT_CK("apb:uart3", NULL, &clk_uart3), @@ -140,6 +183,7 @@ static struct clk_lookup clocks[] = { INIT_CK(NULL, "pll2", &clk_pll2), INIT_CK("ep93xx-ohci", NULL, &clk_usb_host), INIT_CK("ep93xx-keypad", NULL, &clk_keypad), + INIT_CK("ep93xx-fb", NULL, &clk_video), INIT_CK(NULL, "pwm_clk", &clk_pwm), INIT_CK(NULL, "m2p0", &clk_m2p0), INIT_CK(NULL, "m2p1", &clk_m2p1), @@ -155,48 +199,84 @@ static struct clk_lookup clocks[] = { INIT_CK(NULL, "m2m1", &clk_m2m1), }; +static DEFINE_SPINLOCK(clk_lock); + +static void __clk_enable(struct clk *clk) +{ + if (!clk->users++) { + if (clk->parent) + __clk_enable(clk->parent); + + if (clk->enable_reg) { + u32 v; + + v = __raw_readl(clk->enable_reg); + v |= clk->enable_mask; + if (clk->sw_locked) + ep93xx_syscon_swlocked_write(v, clk->enable_reg); + else + __raw_writel(v, clk->enable_reg); + } + } +} int clk_enable(struct clk *clk) { - if (!clk->users++ && clk->enable_reg) { - u32 value; + unsigned long flags; - value = __raw_readl(clk->enable_reg); - value |= clk->enable_mask; - if (clk->sw_locked) - ep93xx_syscon_swlocked_write(value, clk->enable_reg); - else - __raw_writel(value, clk->enable_reg); - } + if (!clk) + return -EINVAL; + + spin_lock_irqsave(&clk_lock, flags); + __clk_enable(clk); + spin_unlock_irqrestore(&clk_lock, flags); return 0; } EXPORT_SYMBOL(clk_enable); +static void __clk_disable(struct clk *clk) +{ + if (!--clk->users) { + if (clk->enable_reg) { + u32 v; + + v = __raw_readl(clk->enable_reg); + v &= ~clk->enable_mask; + if (clk->sw_locked) + ep93xx_syscon_swlocked_write(v, clk->enable_reg); + else + __raw_writel(v, clk->enable_reg); + } + + if (clk->parent) + __clk_disable(clk->parent); + } +} + void clk_disable(struct clk *clk) { - if (!--clk->users && clk->enable_reg) { - u32 value; + unsigned long flags; - value = __raw_readl(clk->enable_reg); - value &= ~clk->enable_mask; - if (clk->sw_locked) - ep93xx_syscon_swlocked_write(value, clk->enable_reg); - else - __raw_writel(value, clk->enable_reg); - } + if (!clk) + return; + + spin_lock_irqsave(&clk_lock, flags); + __clk_disable(clk); + spin_unlock_irqrestore(&clk_lock, flags); } EXPORT_SYMBOL(clk_disable); static unsigned long get_uart_rate(struct clk *clk) { + unsigned long rate = clk_get_rate(clk->parent); u32 value; value = __raw_readl(EP93XX_SYSCON_PWRCNT); if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD) - return EP93XX_EXT_CLK_RATE; + return rate; else - return EP93XX_EXT_CLK_RATE / 2; + return rate / 2; } unsigned long clk_get_rate(struct clk *clk) @@ -236,6 +316,84 @@ static int set_keytchclk_rate(struct clk *clk, unsigned long rate) return 0; } +static int calc_clk_div(struct clk *clk, unsigned long rate, + int *psel, int *esel, int *pdiv, int *div) +{ + struct clk *mclk; + unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1; + int i, found = 0, __div = 0, __pdiv = 0; + + /* Don't exceed the maximum rate */ + max_rate = max(max(clk_pll1.rate / 4, clk_pll2.rate / 4), + clk_xtali.rate / 4); + rate = min(rate, max_rate); + + /* + * Try the two pll's and the external clock + * Because the valid predividers are 2, 2.5 and 3, we multiply + * all the clocks by 2 to avoid floating point math. + * + * This is based on the algorithm in the ep93xx raster guide: + * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf + * + */ + for (i = 0; i < 3; i++) { + if (i == 0) + mclk = &clk_xtali; + else if (i == 1) + mclk = &clk_pll1; + else + mclk = &clk_pll2; + mclk_rate = mclk->rate * 2; + + /* Try each predivider value */ + for (__pdiv = 4; __pdiv <= 6; __pdiv++) { + __div = mclk_rate / (rate * __pdiv); + if (__div < 2 || __div > 127) + continue; + + actual_rate = mclk_rate / (__pdiv * __div); + + if (!found || abs(actual_rate - rate) < rate_err) { + *pdiv = __pdiv - 3; + *div = __div; + *psel = (i == 2); + *esel = (i != 0); + clk->parent = mclk; + clk->rate = actual_rate; + rate_err = abs(actual_rate - rate); + found = 1; + } + } + } + + if (!found) + return -EINVAL; + + return 0; +} + +static int set_div_rate(struct clk *clk, unsigned long rate) +{ + int err, psel = 0, esel = 0, pdiv = 0, div = 0; + u32 val; + + err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div); + if (err) + return err; + + /* Clear the esel, psel, pdiv and div bits */ + val = __raw_readl(clk->enable_reg); + val &= ~0x7fff; + + /* Set the new esel, psel, pdiv and div bits for the new clock rate */ + val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) | + (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) | + (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div; + ep93xx_syscon_swlocked_write(val, clk->enable_reg); + return 0; +} + int clk_set_rate(struct clk *clk, unsigned long rate) { if (clk->set_rate) @@ -258,7 +416,7 @@ static unsigned long calc_pll_rate(u32 config_word) unsigned long long rate; int i; - rate = EP93XX_EXT_CLK_RATE; + rate = clk_xtali.rate; rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */ rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */ do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */ @@ -291,7 +449,7 @@ static int __init ep93xx_clock_init(void) value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1); if (!(value & 0x00800000)) { /* PLL1 bypassed? */ - clk_pll1.rate = EP93XX_EXT_CLK_RATE; + clk_pll1.rate = clk_xtali.rate; } else { clk_pll1.rate = calc_pll_rate(value); } @@ -302,7 +460,7 @@ static int __init ep93xx_clock_init(void) value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2); if (!(value & 0x00080000)) { /* PLL2 bypassed? */ - clk_pll2.rate = EP93XX_EXT_CLK_RATE; + clk_pll2.rate = clk_xtali.rate; } else if (value & 0x00040000) { /* PLL2 enabled? */ clk_pll2.rate = calc_pll_rate(value); } else { |