Linux-2.6.33.2/arch/arm/mach-ep93xx/clock.c
/*
* 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.
*/
#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 <mach/hardware.h>
#include <asm/clkdev.h>
#include <asm/div64.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 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);