kernel-fxtec-pro1x/arch/arm/mach-s3c2443/clock.c
Ben Dooks 2dd5f18142 ARM: S3C2443: Update notes on MPLLREF clock
Add note on MPLLREF clock source and why it cannot be easily removed.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2010-03-07 22:56:12 +00:00

790 lines
18 KiB
C

/* linux/arch/arm/mach-s3c2443/clock.c
*
* Copyright (c) 2007, 2010 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2443 Clock control support
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/sysdev.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/serial_core.h>
#include <linux/io.h>
#include <asm/mach/map.h>
#include <mach/hardware.h>
#include <mach/regs-s3c2443-clock.h>
#include <plat/cpu-freq.h>
#include <plat/s3c2443.h>
#include <plat/clock.h>
#include <plat/clock-clksrc.h>
#include <plat/cpu.h>
/* We currently have to assume that the system is running
* from the XTPll input, and that all ***REFCLKs are being
* fed from it, as we cannot read the state of OM[4] from
* software.
*
* It would be possible for each board initialisation to
* set the correct muxing at initialisation
*/
static int s3c2443_gate(void __iomem *reg, struct clk *clk, int enable)
{
u32 ctrlbit = clk->ctrlbit;
u32 con = __raw_readl(reg);
if (enable)
con |= ctrlbit;
else
con &= ~ctrlbit;
__raw_writel(con, reg);
return 0;
}
static int s3c2443_clkcon_enable_h(struct clk *clk, int enable)
{
return s3c2443_gate(S3C2443_HCLKCON, clk, enable);
}
static int s3c2443_clkcon_enable_p(struct clk *clk, int enable)
{
return s3c2443_gate(S3C2443_PCLKCON, clk, enable);
}
static int s3c2443_clkcon_enable_s(struct clk *clk, int enable)
{
return s3c2443_gate(S3C2443_SCLKCON, clk, enable);
}
/* clock selections */
/* mpllref is a direct descendant of clk_xtal by default, but it is not
* elided as the EPLL can be either sourced by the XTAL or EXTCLK and as
* such directly equating the two source clocks is impossible.
*/
static struct clk clk_mpllref = {
.name = "mpllref",
.parent = &clk_xtal,
.id = -1,
};
#if 0
static struct clk clk_mpll = {
.name = "mpll",
.parent = &clk_mpllref,
.id = -1,
};
#endif
static struct clk clk_i2s_ext = {
.name = "i2s-ext",
.id = -1,
};
static struct clk *clk_epllref_sources[] = {
[0] = &clk_mpllref,
[1] = &clk_mpllref,
[2] = &clk_xtal,
[3] = &clk_ext,
};
static struct clksrc_clk clk_epllref = {
.clk = {
.name = "epllref",
.id = -1,
},
.sources = &(struct clksrc_sources) {
.sources = clk_epllref_sources,
.nr_sources = ARRAY_SIZE(clk_epllref_sources),
},
.reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 7 },
};
static unsigned long s3c2443_getrate_mdivclk(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long div = __raw_readl(S3C2443_CLKDIV0);
div &= S3C2443_CLKDIV0_EXTDIV_MASK;
div >>= (S3C2443_CLKDIV0_EXTDIV_SHIFT-1); /* x2 */
return parent_rate / (div + 1);
}
static struct clk clk_mdivclk = {
.name = "mdivclk",
.parent = &clk_mpllref,
.id = -1,
.ops = &(struct clk_ops) {
.get_rate = s3c2443_getrate_mdivclk,
},
};
static struct clk *clk_msysclk_sources[] = {
[0] = &clk_mpllref,
[1] = &clk_mpll,
[2] = &clk_mdivclk,
[3] = &clk_mpllref,
};
static struct clksrc_clk clk_msysclk = {
.clk = {
.name = "msysclk",
.parent = &clk_xtal,
.id = -1,
},
.sources = &(struct clksrc_sources) {
.sources = clk_msysclk_sources,
.nr_sources = ARRAY_SIZE(clk_msysclk_sources),
},
.reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 3 },
};
/* armdiv
*
* this clock is sourced from msysclk and can have a number of
* divider values applied to it to then be fed into armclk.
*/
static struct clk clk_armdiv = {
.name = "armdiv",
.id = -1,
.parent = &clk_msysclk.clk,
};
/* armclk
*
* this is the clock fed into the ARM core itself, from armdiv or from hclk.
*/
static struct clk *clk_arm_sources[] = {
[0] = &clk_armdiv,
[1] = &clk_h,
};
static struct clksrc_clk clk_arm = {
.clk = {
.name = "armclk",
.id = -1,
},
.sources = &(struct clksrc_sources) {
.sources = clk_arm_sources,
.nr_sources = ARRAY_SIZE(clk_arm_sources),
},
.reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 },
};
/* esysclk
*
* this is sourced from either the EPLL or the EPLLref clock
*/
static struct clk *clk_sysclk_sources[] = {
[0] = &clk_epllref.clk,
[1] = &clk_epll,
};
static struct clksrc_clk clk_esysclk = {
.clk = {
.name = "esysclk",
.parent = &clk_epll,
.id = -1,
},
.sources = &(struct clksrc_sources) {
.sources = clk_sysclk_sources,
.nr_sources = ARRAY_SIZE(clk_sysclk_sources),
},
.reg_src = { .reg = S3C2443_CLKSRC, .size = 1, .shift = 6 },
};
/* uartclk
*
* UART baud-rate clock sourced from esysclk via a divisor
*/
static struct clksrc_clk clk_uart = {
.clk = {
.name = "uartclk",
.id = -1,
.parent = &clk_esysclk.clk,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 8 },
};
/* hsspi
*
* high-speed spi clock, sourced from esysclk
*/
static struct clksrc_clk clk_hsspi = {
.clk = {
.name = "hsspi",
.id = -1,
.parent = &clk_esysclk.clk,
.ctrlbit = S3C2443_SCLKCON_HSSPICLK,
.enable = s3c2443_clkcon_enable_s,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};
/* usbhost
*
* usb host bus-clock, usually 48MHz to provide USB bus clock timing
*/
static struct clksrc_clk clk_usb_bus_host = {
.clk = {
.name = "usb-bus-host-parent",
.id = -1,
.parent = &clk_esysclk.clk,
.ctrlbit = S3C2443_SCLKCON_USBHOST,
.enable = s3c2443_clkcon_enable_s,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};
/* clk_hsmcc_div
*
* this clock is sourced from epll, and is fed through a divider,
* to a mux controlled by sclkcon where either it or a extclk can
* be fed to the hsmmc block
*/
static struct clksrc_clk clk_hsmmc_div = {
.clk = {
.name = "hsmmc-div",
.id = -1,
.parent = &clk_esysclk.clk,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 },
};
static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2443_SCLKCON);
clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT |
S3C2443_SCLKCON_HSMMCCLK_EPLL);
if (parent == &clk_epll)
clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL;
else if (parent == &clk_ext)
clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT;
else
return -EINVAL;
if (clk->usage > 0) {
__raw_writel(clksrc, S3C2443_SCLKCON);
}
clk->parent = parent;
return 0;
}
static int s3c2443_enable_hsmmc(struct clk *clk, int enable)
{
return s3c2443_setparent_hsmmc(clk, clk->parent);
}
static struct clk clk_hsmmc = {
.name = "hsmmc-if",
.id = -1,
.parent = &clk_hsmmc_div.clk,
.enable = s3c2443_enable_hsmmc,
.ops = &(struct clk_ops) {
.set_parent = s3c2443_setparent_hsmmc,
},
};
/* i2s_eplldiv
*
* This clock is the output from the I2S divisor of ESYSCLK, and is seperate
* from the mux that comes after it (cannot merge into one single clock)
*/
static struct clksrc_clk clk_i2s_eplldiv = {
.clk = {
.name = "i2s-eplldiv",
.id = -1,
.parent = &clk_esysclk.clk,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, },
};
/* i2s-ref
*
* i2s bus reference clock, selectable from external, esysclk or epllref
*
* Note, this used to be two clocks, but was compressed into one.
*/
struct clk *clk_i2s_srclist[] = {
[0] = &clk_i2s_eplldiv.clk,
[1] = &clk_i2s_ext,
[2] = &clk_epllref.clk,
[3] = &clk_epllref.clk,
};
static struct clksrc_clk clk_i2s = {
.clk = {
.name = "i2s-if",
.id = -1,
.ctrlbit = S3C2443_SCLKCON_I2SCLK,
.enable = s3c2443_clkcon_enable_s,
},
.sources = &(struct clksrc_sources) {
.sources = clk_i2s_srclist,
.nr_sources = ARRAY_SIZE(clk_i2s_srclist),
},
.reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 },
};
/* cam-if
*
* camera interface bus-clock, divided down from esysclk
*/
static struct clksrc_clk clk_cam = {
.clk = {
.name = "camif-upll", /* same as 2440 name */
.id = -1,
.parent = &clk_esysclk.clk,
.ctrlbit = S3C2443_SCLKCON_CAMCLK,
.enable = s3c2443_clkcon_enable_s,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 26 },
};
/* display-if
*
* display interface clock, divided from esysclk
*/
static struct clksrc_clk clk_display = {
.clk = {
.name = "display-if",
.id = -1,
.parent = &clk_esysclk.clk,
.ctrlbit = S3C2443_SCLKCON_DISPCLK,
.enable = s3c2443_clkcon_enable_s,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 8, .shift = 16 },
};
/* prediv
*
* this divides the msysclk down to pass to h/p/etc.
*/
static unsigned long s3c2443_prediv_getrate(struct clk *clk)
{
unsigned long rate = clk_get_rate(clk->parent);
unsigned long clkdiv0 = __raw_readl(S3C2443_CLKDIV0);
clkdiv0 &= S3C2443_CLKDIV0_PREDIV_MASK;
clkdiv0 >>= S3C2443_CLKDIV0_PREDIV_SHIFT;
return rate / (clkdiv0 + 1);
}
static struct clk clk_prediv = {
.name = "prediv",
.id = -1,
.parent = &clk_msysclk.clk,
.ops = &(struct clk_ops) {
.get_rate = s3c2443_prediv_getrate,
},
};
/* standard clock definitions */
static struct clk init_clocks_disable[] = {
{
.name = "nand",
.id = -1,
.parent = &clk_h,
}, {
.name = "sdi",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SDI,
}, {
.name = "adc",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_ADC,
}, {
.name = "i2c",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_IIC,
}, {
.name = "iis",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_IIS,
}, {
.name = "spi",
.id = 0,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SPI0,
}, {
.name = "spi",
.id = 1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SPI1,
}
};
static struct clk init_clocks[] = {
{
.name = "dma",
.id = 0,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA0,
}, {
.name = "dma",
.id = 1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA1,
}, {
.name = "dma",
.id = 2,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA2,
}, {
.name = "dma",
.id = 3,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA3,
}, {
.name = "dma",
.id = 4,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA4,
}, {
.name = "dma",
.id = 5,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_DMA5,
}, {
.name = "lcd",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_LCDC,
}, {
.name = "gpio",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_GPIO,
}, {
.name = "usb-host",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_USBH,
}, {
.name = "usb-device",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_USBD,
}, {
.name = "hsmmc",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_HSMMC,
}, {
.name = "cfc",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_CFC,
}, {
.name = "ssmc",
.id = -1,
.parent = &clk_h,
.enable = s3c2443_clkcon_enable_h,
.ctrlbit = S3C2443_HCLKCON_SSMC,
}, {
.name = "timers",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_PWMT,
}, {
.name = "uart",
.id = 0,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_UART0,
}, {
.name = "uart",
.id = 1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_UART1,
}, {
.name = "uart",
.id = 2,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_UART2,
}, {
.name = "uart",
.id = 3,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_UART3,
}, {
.name = "rtc",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_RTC,
}, {
.name = "watchdog",
.id = -1,
.parent = &clk_p,
.ctrlbit = S3C2443_PCLKCON_WDT,
}, {
.name = "usb-bus-host",
.id = -1,
.parent = &clk_usb_bus_host.clk,
}, {
.name = "ac97",
.id = -1,
.parent = &clk_p,
.ctrlbit = S3C2443_PCLKCON_AC97,
}
};
/* clocks to add where we need to check their parentage */
static struct clksrc_clk __initdata *init_list[] = {
&clk_epllref, /* should be first */
&clk_esysclk,
&clk_msysclk,
&clk_arm,
&clk_i2s_eplldiv,
&clk_i2s,
&clk_cam,
&clk_uart,
&clk_display,
&clk_hsmmc_div,
&clk_usb_bus_host,
};
static void __init s3c2443_clk_initparents(void)
{
int ptr;
for (ptr = 0; ptr < ARRAY_SIZE(init_list); ptr++)
s3c_set_clksrc(init_list[ptr], true);
}
/* armdiv divisor table */
static unsigned int armdiv[16] = {
[S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 1,
[S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 2,
[S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 3,
[S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 4,
[S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 6,
[S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 8,
[S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 12,
[S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 16,
};
static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0)
{
clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT];
}
static inline unsigned long s3c2443_get_hdiv(unsigned long clkcon0)
{
clkcon0 &= S3C2443_CLKDIV0_HCLKDIV_MASK;
return clkcon0 + 1;
}
/* clocks to add straight away */
static struct clksrc_clk *clksrcs[] __initdata = {
&clk_usb_bus_host,
&clk_epllref,
&clk_esysclk,
&clk_msysclk,
&clk_arm,
&clk_uart,
&clk_display,
&clk_cam,
&clk_i2s_eplldiv,
&clk_i2s,
&clk_hsspi,
&clk_hsmmc_div,
};
static struct clk *clks[] __initdata = {
&clk_ext,
&clk_epll,
&clk_usb_bus,
&clk_mpllref,
&clk_hsmmc,
&clk_armdiv,
&clk_prediv,
};
void __init_or_cpufreq s3c2443_setup_clocks(void)
{
unsigned long mpllcon = __raw_readl(S3C2443_MPLLCON);
unsigned long clkdiv0 = __raw_readl(S3C2443_CLKDIV0);
struct clk *xtal_clk;
unsigned long xtal;
unsigned long pll;
unsigned long fclk;
unsigned long hclk;
unsigned long pclk;
xtal_clk = clk_get(NULL, "xtal");
xtal = clk_get_rate(xtal_clk);
clk_put(xtal_clk);
pll = s3c2443_get_mpll(mpllcon, xtal);
clk_msysclk.clk.rate = pll;
fclk = pll / s3c2443_fclk_div(clkdiv0);
hclk = s3c2443_prediv_getrate(&clk_prediv);
hclk /= s3c2443_get_hdiv(clkdiv0);
pclk = hclk / ((clkdiv0 & S3C2443_CLKDIV0_HALF_PCLK) ? 2 : 1);
s3c24xx_setup_clocks(fclk, hclk, pclk);
printk("S3C2443: mpll %s %ld.%03ld MHz, cpu %ld.%03ld MHz, mem %ld.%03ld MHz, pclk %ld.%03ld MHz\n",
(mpllcon & S3C2443_PLLCON_OFF) ? "off":"on",
print_mhz(pll), print_mhz(fclk),
print_mhz(hclk), print_mhz(pclk));
s3c24xx_setup_clocks(fclk, hclk, pclk);
}
void __init s3c2443_init_clocks(int xtal)
{
struct clk *clkp;
unsigned long epllcon = __raw_readl(S3C2443_EPLLCON);
int ret;
int ptr;
/* s3c2443 parents h and p clocks from prediv */
clk_h.parent = &clk_prediv;
clk_p.parent = &clk_prediv;
s3c24xx_register_baseclocks(xtal);
s3c2443_setup_clocks();
s3c2443_clk_initparents();
for (ptr = 0; ptr < ARRAY_SIZE(clks); ptr++) {
clkp = clks[ptr];
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
}
for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++)
s3c_register_clksrc(clksrcs[ptr], 1);
clk_epll.rate = s3c2443_get_epll(epllcon, xtal);
clk_epll.parent = &clk_epllref.clk;
clk_usb_bus.parent = &clk_usb_bus_host.clk;
/* ensure usb bus clock is within correct rate of 48MHz */
if (clk_get_rate(&clk_usb_bus_host.clk) != (48 * 1000 * 1000)) {
printk(KERN_INFO "Warning: USB host bus not at 48MHz\n");
clk_set_rate(&clk_usb_bus_host.clk, 48*1000*1000);
}
printk("S3C2443: epll %s %ld.%03ld MHz, usb-bus %ld.%03ld MHz\n",
(epllcon & S3C2443_PLLCON_OFF) ? "off":"on",
print_mhz(clk_get_rate(&clk_epll)),
print_mhz(clk_get_rate(&clk_usb_bus)));
/* register clocks from clock array */
s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks));
/* We must be careful disabling the clocks we are not intending to
* be using at boot time, as subsystems such as the LCD which do
* their own DMA requests to the bus can cause the system to lockup
* if they where in the middle of requesting bus access.
*
* Disabling the LCD clock if the LCD is active is very dangerous,
* and therefore the bootloader should be careful to not enable
* the LCD clock if it is not needed.
*/
/* install (and disable) the clocks we do not need immediately */
clkp = init_clocks_disable;
for (ptr = 0; ptr < ARRAY_SIZE(init_clocks_disable); ptr++, clkp++) {
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
(clkp->enable)(clkp, 0);
}
s3c_pwmclk_init();
}