diff options
Diffstat (limited to 'arch/arm/mach-ep93xx/clock.c')
-rw-r--r-- | arch/arm/mach-ep93xx/clock.c | 217 |
1 files changed, 173 insertions, 44 deletions
diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c index 6c4c163..dda19cd7 100644 --- a/arch/arm/mach-ep93xx/clock.c +++ b/arch/arm/mach-ep93xx/clock.c @@ -22,48 +22,39 @@ #include <mach/hardware.h> -/* - * The EP93xx has two external crystal oscillators. To generate the - * required high-frequency clocks, the processor uses two phase-locked- - * loops (PLLs) to multiply the incoming external clock signal to much - * higher frequencies that are then divided down by programmable dividers - * to produce the needed clocks. The PLLs operate independently of one - * another. - */ -#define EP93XX_EXT_CLK_RATE 14745600 -#define EP93XX_EXT_RTC_RATE 32768 - - struct clk { unsigned long rate; int users; int sw_locked; - u32 enable_reg; + void __iomem *enable_reg; u32 enable_mask; unsigned long (*get_rate)(struct clk *clk); + int (*set_rate)(struct clk *clk, unsigned long rate); }; 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_uart1 = { .sw_locked = 1, - .enable_reg = EP93XX_SYSCON_DEVICE_CONFIG, - .enable_mask = EP93XX_SYSCON_DEVICE_CONFIG_U1EN, + .enable_reg = EP93XX_SYSCON_DEVCFG, + .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN, .get_rate = get_uart_rate, }; static struct clk clk_uart2 = { .sw_locked = 1, - .enable_reg = EP93XX_SYSCON_DEVICE_CONFIG, - .enable_mask = EP93XX_SYSCON_DEVICE_CONFIG_U2EN, + .enable_reg = EP93XX_SYSCON_DEVCFG, + .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN, .get_rate = get_uart_rate, }; static struct clk clk_uart3 = { .sw_locked = 1, - .enable_reg = EP93XX_SYSCON_DEVICE_CONFIG, - .enable_mask = EP93XX_SYSCON_DEVICE_CONFIG_U3EN, + .enable_reg = EP93XX_SYSCON_DEVCFG, + .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN, .get_rate = get_uart_rate, }; static struct clk clk_pll1; @@ -75,6 +66,22 @@ static struct clk clk_usb_host = { .enable_reg = EP93XX_SYSCON_PWRCNT, .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN, }; +static struct clk clk_keypad = { + .sw_locked = 1, + .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV, + .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN, + .set_rate = set_keytchclk_rate, +}; +static struct clk clk_pwm = { + .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 = { @@ -130,27 +137,30 @@ static struct clk clk_m2m1 = { { .dev_id = dev, .con_id = con, .clk = ck } static struct clk_lookup clocks[] = { - INIT_CK("apb:uart1", NULL, &clk_uart1), - INIT_CK("apb:uart2", NULL, &clk_uart2), - INIT_CK("apb:uart3", NULL, &clk_uart3), - INIT_CK(NULL, "pll1", &clk_pll1), - INIT_CK(NULL, "fclk", &clk_f), - INIT_CK(NULL, "hclk", &clk_h), - INIT_CK(NULL, "pclk", &clk_p), - INIT_CK(NULL, "pll2", &clk_pll2), - INIT_CK("ep93xx-ohci", NULL, &clk_usb_host), - INIT_CK(NULL, "m2p0", &clk_m2p0), - INIT_CK(NULL, "m2p1", &clk_m2p1), - INIT_CK(NULL, "m2p2", &clk_m2p2), - INIT_CK(NULL, "m2p3", &clk_m2p3), - INIT_CK(NULL, "m2p4", &clk_m2p4), - INIT_CK(NULL, "m2p5", &clk_m2p5), - INIT_CK(NULL, "m2p6", &clk_m2p6), - INIT_CK(NULL, "m2p7", &clk_m2p7), - INIT_CK(NULL, "m2p8", &clk_m2p8), - INIT_CK(NULL, "m2p9", &clk_m2p9), - INIT_CK(NULL, "m2m0", &clk_m2m0), - INIT_CK(NULL, "m2m1", &clk_m2m1), + INIT_CK("apb:uart1", NULL, &clk_uart1), + INIT_CK("apb:uart2", NULL, &clk_uart2), + INIT_CK("apb:uart3", NULL, &clk_uart3), + INIT_CK(NULL, "pll1", &clk_pll1), + INIT_CK(NULL, "fclk", &clk_f), + INIT_CK(NULL, "hclk", &clk_h), + INIT_CK(NULL, "pclk", &clk_p), + 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), + INIT_CK(NULL, "m2p2", &clk_m2p2), + INIT_CK(NULL, "m2p3", &clk_m2p3), + INIT_CK(NULL, "m2p4", &clk_m2p4), + INIT_CK(NULL, "m2p5", &clk_m2p5), + INIT_CK(NULL, "m2p6", &clk_m2p6), + INIT_CK(NULL, "m2p7", &clk_m2p7), + INIT_CK(NULL, "m2p8", &clk_m2p8), + INIT_CK(NULL, "m2p9", &clk_m2p9), + INIT_CK(NULL, "m2m0", &clk_m2m0), + INIT_CK(NULL, "m2m1", &clk_m2m1), }; @@ -160,9 +170,11 @@ int clk_enable(struct clk *clk) u32 value; value = __raw_readl(clk->enable_reg); + value |= clk->enable_mask; if (clk->sw_locked) - __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK); - __raw_writel(value | clk->enable_mask, clk->enable_reg); + ep93xx_syscon_swlocked_write(value, clk->enable_reg); + else + __raw_writel(value, clk->enable_reg); } return 0; @@ -175,9 +187,11 @@ void clk_disable(struct clk *clk) u32 value; value = __raw_readl(clk->enable_reg); + value &= ~clk->enable_mask; if (clk->sw_locked) - __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK); - __raw_writel(value & ~clk->enable_mask, clk->enable_reg); + ep93xx_syscon_swlocked_write(value, clk->enable_reg); + else + __raw_writel(value, clk->enable_reg); } } EXPORT_SYMBOL(clk_disable); @@ -202,6 +216,121 @@ unsigned long clk_get_rate(struct clk *clk) } EXPORT_SYMBOL(clk_get_rate); +static int set_keytchclk_rate(struct clk *clk, unsigned long rate) +{ + u32 val; + u32 div_bit; + + val = __raw_readl(clk->enable_reg); + + /* + * The Key Matrix and ADC clocks are configured using the same + * System Controller register. The clock used will be either + * 1/4 or 1/16 the external clock rate depending on the + * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV + * bit being set or cleared. + */ + div_bit = clk->enable_mask >> 15; + + if (rate == EP93XX_KEYTCHCLK_DIV4) + val |= div_bit; + else if (rate == EP93XX_KEYTCHCLK_DIV16) + val &= ~div_bit; + else + return -EINVAL; + + ep93xx_syscon_swlocked_write(val, clk->enable_reg); + clk->rate = rate; + return 0; +} + +static unsigned long calc_clk_div(unsigned long rate, int *psel, int *esel, + int *pdiv, int *div) +{ + unsigned long max_rate, best_rate = 0, + actual_rate = 0, mclk_rate = 0, 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), + (unsigned long)EP93XX_EXT_CLK_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_rate = EP93XX_EXT_CLK_RATE * 2; + else if (i == 1) + mclk_rate = clk_pll1.rate * 2; + else if (i == 2) + mclk_rate = clk_pll2.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); + best_rate = actual_rate; + rate_err = abs(actual_rate - rate); + found = 1; + } + } + } + + if (!found) + return 0; + + return best_rate; +} + +static int set_div_rate(struct clk *clk, unsigned long rate) +{ + unsigned long actual_rate; + int psel = 0, esel = 0, pdiv = 0, div = 0; + u32 val; + + actual_rate = calc_clk_div(rate, &psel, &esel, &pdiv, &div); + if (actual_rate == 0) + return -EINVAL; + clk->rate = actual_rate; + + /* 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) + return clk->set_rate(clk, rate); + + return -EINVAL; +} +EXPORT_SYMBOL(clk_set_rate); + static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 }; static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 }; |