- 根目录:
- arch
- arm
- mach-mxs
- clock-mx23.c
/*
* Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/clkdev.h>
#include <asm/clkdev.h>
#include <asm/div64.h>
#include <mach/mx23.h>
#include <mach/common.h>
#include <mach/clock.h>
#include "regs-clkctrl-mx23.h"
#define CLKCTRL_BASE_ADDR MX23_IO_ADDRESS(MX23_CLKCTRL_BASE_ADDR)
#define DIGCTRL_BASE_ADDR MX23_IO_ADDRESS(MX23_DIGCTL_BASE_ADDR)
#define PARENT_RATE_SHIFT 8
static int _raw_clk_enable(struct clk *clk)
{
u32 reg;
if (clk->enable_reg) {
reg = __raw_readl(clk->enable_reg);
reg &= ~(1 << clk->enable_shift);
__raw_writel(reg, clk->enable_reg);
}
return 0;
}
static void _raw_clk_disable(struct clk *clk)
{
u32 reg;
if (clk->enable_reg) {
reg = __raw_readl(clk->enable_reg);
reg |= 1 << clk->enable_shift;
__raw_writel(reg, clk->enable_reg);
}
}
/*
* ref_xtal_clk
*/
static unsigned long ref_xtal_clk_get_rate(struct clk *clk)
{
return 24000000;
}
static struct clk ref_xtal_clk = {
.get_rate = ref_xtal_clk_get_rate,
};
/*
* pll_clk
*/
static unsigned long pll_clk_get_rate(struct clk *clk)
{
return 480000000;
}
static int pll_clk_enable(struct clk *clk)
{
__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_SET);
/* Only a 10us delay is need. PLLCTRL1 LOCK bitfied is only a timer
* and is incorrect (excessive). Per definition of the PLLCTRL0
* POWER field, waiting at least 10us.
*/
udelay(10);
return 0;
}
static void pll_clk_disable(struct clk *clk)
{
__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_CLR);
}
static struct clk pll_clk = {
.get_rate = pll_clk_get_rate,
.enable = pll_clk_enable,
.disable = pll_clk_disable,
.parent = &ref_xtal_clk,
};
/*
* ref_clk
*/
#define _CLK_GET_RATE_REF(name, sr, ss) \
static unsigned long name##_get_rate(struct clk *clk) \
{ \
unsigned long parent_rate; \
u32 reg, div; \
\
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##sr); \
div = (reg >> BP_CLKCTRL_##sr##_##ss##FRAC) & 0x3f; \
parent_rate = clk_get_rate(clk->parent); \
\
return SH_DIV((parent_rate >> PARENT_RATE_SHIFT) * 18, \
div, PARENT_RATE_SHIFT); \
}
_CLK_GET_RATE_REF(ref_cpu_clk, FRAC, CPU)
_CLK_GET_RATE_REF(ref_emi_clk, FRAC, EMI)
_CLK_GET_RATE_REF(ref_pix_clk, FRAC, PIX)
_CLK_GET_RATE_REF(ref_io_clk, FRAC, IO)
#define _DEFINE_CLOCK_REF(name, er, es) \
static struct clk name = { \
.enable_reg = CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er, \
.enable_shift = BP_CLKCTRL_##er##_CLKGATE##es, \
.get_rate = name##_get_rate, \
.enable = _raw_clk_enable, \
.disable = _raw_clk_disable, \
.parent = &pll_clk, \
}
_DEFINE_CLOCK_REF(ref_cpu_clk, FRAC, CPU);
_DEFINE_CLOCK_REF(ref_emi_clk, FRAC, EMI);
_DEFINE_CLOCK_REF(ref_pix_clk, FRAC, PIX);
_DEFINE_CLOCK_REF(ref_io_clk, FRAC, IO);
/*
* General clocks
*
* clk_get_rate
*/
static unsigned long rtc_clk_get_rate(struct clk *clk)
{
/* ref_xtal_clk is implemented as the only parent */
return clk_get_rate(clk->parent) / 768;
}
static unsigned long clk32k_clk_get_rate(struct clk *clk)
{
return clk->parent->get_rate(clk->parent) / 750;
}
#define _CLK_GET_RATE(name, rs) \
static unsigned long name##_get_rate(struct clk *clk) \
{ \
u32 reg, div; \
\
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs); \
\
if (clk->parent == &ref_xtal_clk) \
div = (reg & BM_CLKCTRL_##rs##_DIV_XTAL) >> \
BP_CLKCTRL_##rs##_DIV_XTAL; \
else \
div = (reg & BM_CLKCTRL_##rs##_DIV_##rs) >> \
BP_CLKCTRL_##rs##_DIV_##rs; \
\
if (!div) \
return -EINVAL; \
\
return clk_get_rate(clk->parent) / div; \
}
_CLK_GET_RATE(cpu_clk, CPU)
_CLK_GET_RATE(emi_clk, EMI)
#define _CLK_GET_RATE1(name, rs) \
static unsigned long name##_get_rate(struct clk *clk) \
{ \
u32 reg, div; \
\
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs); \
div = (reg & BM_CLKCTRL_##rs##_DIV) >> BP_CLKCTRL_##rs##_DIV; \
\
if (!div) \
return -EINVAL; \
\
return clk_get_rate(clk->parent) / div; \
}
_CLK_GET_RATE1(hbus_clk, HBUS)
_CLK_GET_RATE1(xbus_clk, XBUS)
_CLK_GET_RATE1(ssp_clk, SSP)
_CLK_GET_RATE1(gpmi_clk, GPMI)
_CLK_GET_RATE1(lcdif_clk, PIX)
#define _CLK_GET_RATE_STUB(name) \
static unsigned long name##_get_rate(struct clk *clk) \
{ \
return clk_get_rate(clk->parent); \
}
_CLK_GET_RATE_STUB(uart_clk)
_CLK_GET_RATE_STUB(audio_clk)
_CLK_GET_RATE_STUB(pwm_clk)
/*
* clk_set_rate
*/
static int cpu_clk_set_rate(struct clk *clk, unsigned long rate)
{
u32 reg, bm_busy, div_max, d, f, div, frac;
unsigned long diff, parent_rate, calc_rate;
int i;
parent_rate = clk_get_rate(clk->parent);
if (clk->parent == &ref_xtal_clk) {
div_max = BM_CLKCTRL_CPU_DIV_XTAL >> BP_CLKCTRL_CPU_DIV_XTAL;
bm_busy = BM_CLKCTRL_CPU_BUSY_REF_XTAL;
div = DIV_ROUND_UP(parent_rate, rate);
if (div == 0 || div > div_max)
return -EINVAL;
} else {
div_max = BM_CLKCTRL_CPU_DIV_CPU >> BP_CLKCTRL_CPU_DIV_CPU;
bm_busy = BM_CLKCTRL_CPU_BUSY_REF_CPU;
rate >>= PARENT_RATE_SHIFT;
parent_rate >>= PARENT_RATE_SHIFT;
diff = parent_rate;
div = frac = 1;
for (d = 1; d <= div_max; d++) {
f = parent_rate * 18 / d / rate;
if ((parent_rate * 18 / d) % rate)
f++;
if (f < 18 || f > 35)
continue;
calc_rate = parent_rate * 18 / f / d;
if (calc_rate > rate)
continue;
if (rate - calc_rate < diff) {
frac = f;
div = d;
diff = rate - calc_rate;
}
if (diff == 0)
break;
}
if (diff == parent_rate)
return -EINVAL;
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
reg &= ~BM_CLKCTRL_FRAC_CPUFRAC;
reg |= frac;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
}
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
reg &= ~BM_CLKCTRL_CPU_DIV_CPU;
reg |= div << BP_CLKCTRL_CPU_DIV_CPU;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
for (i = 10000; i; i--)
if (!(__raw_readl(CLKCTRL_BASE_ADDR +
HW_CLKCTRL_CPU) & bm_busy))
break;
if (!i) {
pr_err("%s: divider writing timeout\n", __func__);
return -ETIMEDOUT;
}
return 0;
}
#define _CLK_SET_RATE(name, dr) \
static int name##_set_rate(struct clk *clk, unsigned long rate) \
{ \
u32 reg, div_max, div; \
unsigned long parent_rate; \
int i; \
\
parent_rate = clk_get_rate(clk->parent); \
div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV; \
\
div = DIV_ROUND_UP(parent_rate, rate); \
if (div == 0 || div > div_max) \
return -EINVAL; \
\
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr); \
reg &= ~BM_CLKCTRL_##dr##_DIV; \
reg |= div << BP_CLKCTRL_##dr##_DIV; \
if (reg & (1 << clk->enable_shift)) { \
pr_err("%s: clock is gated\n", __func__); \
return -EINVAL; \
} \
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr); \
\
for (i = 10000; i; i--) \
if (!(__raw_readl(CLKCTRL_BASE_ADDR + \
HW_CLKCTRL_##dr) & BM_CLKCTRL_##dr##_BUSY)) \
break; \
if (!i) { \
pr_err("%s: divider writing timeout\n", __func__); \
return -ETIMEDOUT; \
} \
\
return 0; \
}
_CLK_SET_RATE(xbus_clk, XBUS)
_CLK_SET_RATE(ssp_clk, SSP)
_CLK_SET_RATE(gpmi_clk, GPMI)
_CLK_SET_RATE(lcdif_clk, PIX)
#define _CLK_SET_RATE_STUB(name) \
static int name##_set_rate(struct clk *clk, unsigned long rate) \
{ \
return -EINVAL; \
}
_CLK_SET_RATE_STUB(emi_clk)
_CLK_SET_RATE_STUB(uart_clk)
_CLK_SET_RATE_STUB(audio_clk)
_CLK_SET_RATE_STUB(pwm_clk)
_CLK_SET_RATE_STUB(clk32k_clk)
/*
* clk_set_parent
*/
#define _CLK_SET_PARENT(name, bit) \
static int name##_set_parent(struct clk *clk, struct clk *parent) \
{ \
if (parent != clk->parent) { \
__raw_writel(BM_CLKCTRL_CLKSEQ_BYPASS_##bit, \
CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ_TOG); \
clk->parent = parent; \
} \
\
return 0; \
}
_CLK_SET_PARENT(cpu_clk, CPU)
_CLK_SET_PARENT(emi_clk, EMI)
_CLK_SET_PARENT(ssp_clk, SSP)
_CLK_SET_PARENT(gpmi_clk, GPMI)
_CLK_SET_PARENT(lcdif_clk, PIX)
#define _CLK_SET_PARENT_STUB(name) \
static int name##_set_parent(struct clk *clk, struct clk *parent) \
{ \
if (parent != clk->parent) \
return -EINVAL; \
else \
return 0; \
}
_CLK_SET_PARENT_STUB(uart_clk)
_CLK_SET_PARENT_STUB(audio_clk)
_CLK_SET_PARENT_STUB(pwm_clk)
_CLK_SET_PARENT_STUB(clk32k_clk)
/*
* clk definition
*/
static struct clk cpu_clk = {
.get_rate = cpu_clk_get_rate,
.set_rate = cpu_clk_set_rate,
.set_parent = cpu_clk_set_parent,
.parent = &ref_cpu_clk,
};
static struct clk hbus_clk = {
.get_rate = hbus_clk_get_rate,
.parent = &cpu_clk,
};
static struct clk xbus_clk = {
.get_rate = xbus_clk_get_rate,
.set_rate = xbus_clk_set_rate,
.parent = &ref_xtal_clk,
};
static struct clk rtc_clk = {
.get_rate = rtc_clk_get_rate,
.parent = &ref_xtal_clk,
};
/* usb_clk gate is controlled in DIGCTRL other than CLKCTRL */
static struct clk usb_clk = {
.enable_reg = DIGCTRL_BASE_ADDR,
.enable_shift = 2,
.enable = _raw_clk_enable,
.disable = _raw_clk_disable,
.parent = &pll_clk,
};
#define _DEFINE_CLOCK(name, er, es, p) \
static struct clk name = { \
.enable_reg = CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er, \
.enable_shift = BP_CLKCTRL_##er##_##es, \
.get_rate = name##_get_rate, \
.set_rate = name##_set_rate, \
.set_parent = name##_set_parent, \
.enable = _raw_clk_enable, \
.disable = _raw_clk_disable, \
.parent = p, \
}
_DEFINE_CLOCK(emi_clk, EMI, CLKGATE, &ref_xtal_clk);
_DEFINE_CLOCK(ssp_clk, SSP, CLKGATE, &ref_xtal_clk);
_DEFINE_CLOCK(gpmi_clk, GPMI, CLKGATE, &ref_xtal_clk);
_DEFINE_CLOCK(lcdif_clk, PIX, CLKGATE, &ref_xtal_clk);
_DEFINE_CLOCK(uart_clk, XTAL, UART_CLK_GATE, &ref_xtal_clk);
_DEFINE_CLOCK(audio_clk, XTAL, FILT_CLK24M_GATE, &ref_xtal_clk);
_DEFINE_CLOCK(pwm_clk, XTAL, PWM_CLK24M_GATE, &ref_xtal_clk);
_DEFINE_CLOCK(clk32k_clk, XTAL, TIMROT_CLK32K_GATE, &ref_xtal_clk);
#define _REGISTER_CLOCK(d, n, c) \
{ \
.dev_id = d, \
.con_id = n, \
.clk = &c, \
},
static struct clk_lookup lookups[] = {
/* for amba bus driver */
_REGISTER_CLOCK("duart", "apb_pclk", xbus_clk)
/* for amba-pl011 driver */
_REGISTER_CLOCK("duart", NULL, uart_clk)
_REGISTER_CLOCK("mxs-auart.0", NULL, uart_clk)
_REGISTER_CLOCK("rtc", NULL, rtc_clk)
_REGISTER_CLOCK("mxs-dma-apbh", NULL, hbus_clk)
_REGISTER_CLOCK("mxs-dma-apbx", NULL, xbus_clk)
_REGISTER_CLOCK(NULL, "usb", usb_clk)
_REGISTER_CLOCK(NULL, "audio", audio_clk)
_REGISTER_CLOCK("mxs-pwm.0", NULL, pwm_clk)
_REGISTER_CLOCK("mxs-pwm.1", NULL, pwm_clk)
_REGISTER_CLOCK("mxs-pwm.2", NULL, pwm_clk)
_REGISTER_CLOCK("mxs-pwm.3", NULL, pwm_clk)
_REGISTER_CLOCK("mxs-pwm.4", NULL, pwm_clk)
_REGISTER_CLOCK("imx23-fb", NULL, lcdif_clk)
};
static int clk_misc_init(void)
{
u32 reg;
int i;
/* Fix up parent per register setting */
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ);
cpu_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_CPU) ?
&ref_xtal_clk : &ref_cpu_clk;
emi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_EMI) ?
&ref_xtal_clk : &ref_emi_clk;
ssp_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_SSP) ?
&ref_xtal_clk : &ref_io_clk;
gpmi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_GPMI) ?
&ref_xtal_clk : &ref_io_clk;
lcdif_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_PIX) ?
&ref_xtal_clk : &ref_pix_clk;
/* Use int div over frac when both are available */
__raw_writel(BM_CLKCTRL_CPU_DIV_XTAL_FRAC_EN,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
__raw_writel(BM_CLKCTRL_CPU_DIV_CPU_FRAC_EN,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
__raw_writel(BM_CLKCTRL_HBUS_DIV_FRAC_EN,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS_CLR);
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
reg &= ~BM_CLKCTRL_XBUS_DIV_FRAC_EN;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
reg &= ~BM_CLKCTRL_SSP_DIV_FRAC_EN;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
reg &= ~BM_CLKCTRL_GPMI_DIV_FRAC_EN;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
reg &= ~BM_CLKCTRL_PIX_DIV_FRAC_EN;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
/*
* Set safe hbus clock divider. A divider of 3 ensure that
* the Vddd voltage required for the cpu clock is sufficiently
* high for the hbus clock.
*/
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
reg &= BM_CLKCTRL_HBUS_DIV;
reg |= 3 << BP_CLKCTRL_HBUS_DIV;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
for (i = 10000; i; i--)
if (!(__raw_readl(CLKCTRL_BASE_ADDR +
HW_CLKCTRL_HBUS) & BM_CLKCTRL_HBUS_BUSY))
break;
if (!i) {
pr_err("%s: divider writing timeout\n", __func__);
return -ETIMEDOUT;
}
/* Gate off cpu clock in WFI for power saving */
__raw_writel(BM_CLKCTRL_CPU_INTERRUPT_WAIT,
CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_SET);
/*
* 480 MHz seems too high to be ssp clock source directly,
* so set frac to get a 288 MHz ref_io.
*/
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
reg &= ~BM_CLKCTRL_FRAC_IOFRAC;
reg |= 30 << BP_CLKCTRL_FRAC_IOFRAC;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
return 0;
}
int __init mx23_clocks_init(void)
{
clk_misc_init();
/*
* source ssp clock from ref_io than ref_xtal,
* as ref_xtal only provides 24 MHz as maximum.
*/
clk_set_parent(&ssp_clk, &ref_io_clk);
clk_enable(&cpu_clk);
clk_enable(&hbus_clk);
clk_enable(&xbus_clk);
clk_enable(&emi_clk);
clk_enable(&uart_clk);
clkdev_add_table(lookups, ARRAY_SIZE(lookups));
mxs_timer_init(&clk32k_clk, MX23_INT_TIMER0);
return 0;
}