diff options
Diffstat (limited to 'kernel/arch/arm/mach-ep93xx/clock.c')
-rw-r--r-- | kernel/arch/arm/mach-ep93xx/clock.c | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-ep93xx/clock.c b/kernel/arch/arm/mach-ep93xx/clock.c new file mode 100644 index 000000000..39ef3b613 --- /dev/null +++ b/kernel/arch/arm/mach-ep93xx/clock.c @@ -0,0 +1,563 @@ +/* + * arch/arm/mach-ep93xx/clock.c + * Clock control for Cirrus EP93xx chips. + * + * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> + * + * 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. + */ + +#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <linux/clkdev.h> + +#include <mach/hardware.h> + +#include <asm/div64.h> + +#include "soc.h" + +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 int set_i2s_sclk_rate(struct clk *clk, unsigned long rate); +static int set_i2s_lrclk_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_spi = { + .parent = &clk_xtali, + .rate = EP93XX_EXT_CLK_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, +}; + +static struct clk clk_i2s_mclk = { + .sw_locked = 1, + .enable_reg = EP93XX_SYSCON_I2SCLKDIV, + .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE, + .set_rate = set_div_rate, +}; + +static struct clk clk_i2s_sclk = { + .sw_locked = 1, + .parent = &clk_i2s_mclk, + .enable_reg = EP93XX_SYSCON_I2SCLKDIV, + .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA, + .set_rate = set_i2s_sclk_rate, +}; + +static struct clk clk_i2s_lrclk = { + .sw_locked = 1, + .parent = &clk_i2s_sclk, + .enable_reg = EP93XX_SYSCON_I2SCLKDIV, + .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA, + .set_rate = set_i2s_lrclk_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, "apb_pclk", &clk_p), + INIT_CK(NULL, "pll2", &clk_pll2), + INIT_CK("ohci-platform", NULL, &clk_usb_host), + INIT_CK("ep93xx-keypad", NULL, &clk_keypad), + INIT_CK("ep93xx-fb", NULL, &clk_video), + INIT_CK("ep93xx-spi.0", NULL, &clk_spi), + INIT_CK("ep93xx-i2s", "mclk", &clk_i2s_mclk), + INIT_CK("ep93xx-i2s", "sclk", &clk_i2s_sclk), + INIT_CK("ep93xx-i2s", "lrclk", &clk_i2s_lrclk), + 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 = max3(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; +} + +static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate) +{ + unsigned val = __raw_readl(clk->enable_reg); + + if (rate == clk_i2s_mclk.rate / 2) + ep93xx_syscon_swlocked_write(val & ~EP93XX_I2SCLKDIV_SDIV, + clk->enable_reg); + else if (rate == clk_i2s_mclk.rate / 4) + ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_SDIV, + clk->enable_reg); + else + return -EINVAL; + + clk_i2s_sclk.rate = rate; + return 0; +} + +static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate) +{ + unsigned val = __raw_readl(clk->enable_reg) & + ~EP93XX_I2SCLKDIV_LRDIV_MASK; + + if (rate == clk_i2s_sclk.rate / 32) + ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV32, + clk->enable_reg); + else if (rate == clk_i2s_sclk.rate / 64) + ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV64, + clk->enable_reg); + else if (rate == clk_i2s_sclk.rate / 128) + ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV128, + clk->enable_reg); + else + return -EINVAL; + + clk_i2s_lrclk.rate = rate; + 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; + + /* Determine the bootloader configured pll1 rate */ + value = __raw_readl(EP93XX_SYSCON_CLKSET1); + if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1)) + clk_pll1.rate = clk_xtali.rate; + else + clk_pll1.rate = calc_pll_rate(value); + + /* Initialize the pll1 derived clocks */ + 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(); + + /* Determine the bootloader configured pll2 rate */ + value = __raw_readl(EP93XX_SYSCON_CLKSET2); + if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2)) + clk_pll2.rate = clk_xtali.rate; + else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN) + clk_pll2.rate = calc_pll_rate(value); + else + clk_pll2.rate = 0; + + /* Initialize the pll2 derived clocks */ + clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1); + + /* + * EP93xx SSP clock rate was doubled in version E2. For more information + * see: + * http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf + */ + if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2) + clk_spi.rate /= 2; + + pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n", + clk_pll1.rate / 1000000, clk_pll2.rate / 1000000); + pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n", + clk_f.rate / 1000000, clk_h.rate / 1000000, + clk_p.rate / 1000000); + + clkdev_add_table(clocks, ARRAY_SIZE(clocks)); + return 0; +} +postcore_initcall(ep93xx_clock_init); |