/* * arch/arm/mach-ep93xx/clock.c * Clock control for Cirrus EP93xx chips. * * Copyright (C) 2006 Lennert Buytenhek * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. */ #include #include #include #include #include #include #include #include #include #include struct clk { struct clk *parent; unsigned long rate; int users; int sw_locked; 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_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 = { .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, }; #define INIT_CK(dev,con,ck) \ { .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), 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), }; 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) { unsigned long flags; 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) { unsigned long flags; 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 rate; else return rate / 2; } unsigned long clk_get_rate(struct clk *clk) { if (clk->get_rate) return clk->get_rate(clk); return clk->rate; } 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 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) 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 }; static char pclk_divisors[] = { 1, 2, 4, 8 }; /* * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS */ static unsigned long calc_pll_rate(u32 config_word) { unsigned long long rate; int i; 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 */ for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */ rate >>= 1; return (unsigned long)rate; } static void __init ep93xx_dma_clock_init(void) { clk_m2p0.rate = clk_h.rate; clk_m2p1.rate = clk_h.rate; clk_m2p2.rate = clk_h.rate; clk_m2p3.rate = clk_h.rate; clk_m2p4.rate = clk_h.rate; clk_m2p5.rate = clk_h.rate; clk_m2p6.rate = clk_h.rate; clk_m2p7.rate = clk_h.rate; clk_m2p8.rate = clk_h.rate; clk_m2p9.rate = clk_h.rate; clk_m2m0.rate = clk_h.rate; clk_m2m1.rate = clk_h.rate; } static int __init ep93xx_clock_init(void) { u32 value; int i; value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1); if (!(value & 0x00800000)) { /* PLL1 bypassed? */ clk_pll1.rate = clk_xtali.rate; } else { clk_pll1.rate = calc_pll_rate(value); } clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7]; clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7]; clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3]; ep93xx_dma_clock_init(); value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2); if (!(value & 0x00080000)) { /* PLL2 bypassed? */ clk_pll2.rate = clk_xtali.rate; } else if (value & 0x00040000) { /* PLL2 enabled? */ clk_pll2.rate = calc_pll_rate(value); } else { clk_pll2.rate = 0; } clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1); printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n", clk_pll1.rate / 1000000, clk_pll2.rate / 1000000); printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n", clk_f.rate / 1000000, clk_h.rate / 1000000, clk_p.rate / 1000000); for (i = 0; i < ARRAY_SIZE(clocks); i++) clkdev_add(&clocks[i]); return 0; } arch_initcall(ep93xx_clock_init);