/* linux/arch/arm/mach-s3c2412/clock.c
*
* Copyright (c) 2006 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2412,S3C2413 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/delay.h>
#include <linux/serial_core.h>
#include <asm/mach/map.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/plat-s3c/regs-serial.h>
#include <asm/arch/regs-clock.h>
#include <asm/arch/regs-gpio.h>
#include <asm/plat-s3c24xx/s3c2412.h>
#include <asm/plat-s3c24xx/clock.h>
#include <asm/plat-s3c24xx/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 s3c2412_clkcon_enable(struct clk *clk, int enable)
{
unsigned int clocks = clk->ctrlbit;
unsigned long clkcon;
clkcon = __raw_readl(S3C2410_CLKCON);
if (enable)
clkcon |= clocks;
else
clkcon &= ~clocks;
__raw_writel(clkcon, S3C2410_CLKCON);
return 0;
}
static int s3c2412_upll_enable(struct clk *clk, int enable)
{
unsigned long upllcon = __raw_readl(S3C2410_UPLLCON);
unsigned long orig = upllcon;
if (!enable)
upllcon |= S3C2412_PLLCON_OFF;
else
upllcon &= ~S3C2412_PLLCON_OFF;
__raw_writel(upllcon, S3C2410_UPLLCON);
/* allow ~150uS for the PLL to settle and lock */
if (enable && (orig & S3C2412_PLLCON_OFF))
udelay(150);
return 0;
}
/* clock selections */
/* CPU EXTCLK input */
static struct clk clk_ext = {
.name = "extclk",
.id = -1,
};
static struct clk clk_erefclk = {
.name = "erefclk",
.id = -1,
};
static struct clk clk_urefclk = {
.name = "urefclk",
.id = -1,
};
static int s3c2412_setparent_usysclk(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_urefclk)
clksrc &= ~S3C2412_CLKSRC_USYSCLK_UPLL;
else if (parent == &clk_upll)
clksrc |= S3C2412_CLKSRC_USYSCLK_UPLL;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static struct clk clk_usysclk = {
.name = "usysclk",
.id = -1,
.parent = &clk_xtal,
.set_parent = s3c2412_setparent_usysclk,
};
static struct clk clk_mrefclk = {
.name = "mrefclk",
.parent = &clk_xtal,
.id = -1,
};
static struct clk clk_mdivclk = {
.name = "mdivclk",
.parent = &clk_xtal,
.id = -1,
};
static int s3c2412_setparent_usbsrc(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_usysclk)
clksrc &= ~S3C2412_CLKSRC_USBCLK_HCLK;
else if (parent == &clk_h)
clksrc |= S3C2412_CLKSRC_USBCLK_HCLK;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static unsigned long s3c2412_roundrate_usbsrc(struct clk *clk,
unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
int div;
if (rate > parent_rate)
return parent_rate;
div = parent_rate / rate;
if (div > 2)
div = 2;
return parent_rate / div;
}
static unsigned long s3c2412_getrate_usbsrc(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long div = __raw_readl(S3C2410_CLKDIVN);
return parent_rate / ((div & S3C2412_CLKDIVN_USB48DIV) ? 2 : 1);
}
static int s3c2412_setrate_usbsrc(struct clk *clk, unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long clkdivn = __raw_readl(S3C2410_CLKDIVN);
rate = s3c2412_roundrate_usbsrc(clk, rate);
if ((parent_rate / rate) == 2)
clkdivn |= S3C2412_CLKDIVN_USB48DIV;
else
clkdivn &= ~S3C2412_CLKDIVN_USB48DIV;
__raw_writel(clkdivn, S3C2410_CLKDIVN);
return 0;
}
static struct clk clk_usbsrc = {
.name = "usbsrc",
.id = -1,
.get_rate = s3c2412_getrate_usbsrc,
.set_rate = s3c2412_setrate_usbsrc,
.round_rate = s3c2412_roundrate_usbsrc,
.set_parent = s3c2412_setparent_usbsrc,
};
static int s3c2412_setparent_msysclk(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_mdivclk)
clksrc &= ~S3C2412_CLKSRC_MSYSCLK_MPLL;
else if (parent == &clk_mpll)
clksrc |= S3C2412_CLKSRC_MSYSCLK_MPLL;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static struct clk clk_msysclk = {
.name = "msysclk",
.id = -1,
.set_parent = s3c2412_setparent_msysclk,
};
static int s3c2412_setparent_armclk(struct clk *clk, struct clk *parent)
{
unsigned long flags;
unsigned long clkdiv;
unsigned long dvs;
/* Note, we current equate fclk andf msysclk for S3C2412 */
if (parent == &clk_msysclk || parent == &clk_f)
dvs = 0;
else if (parent == &clk_h)
dvs = S3C2412_CLKDIVN_DVSEN;
else
return -EINVAL;
clk->parent = parent;
/* update this under irq lockdown, clkdivn is not protected
* by the clock system. */
local_irq_save(flags);
clkdiv = __raw_readl(S3C2410_CLKDIVN);
clkdiv &= ~S3C2412_CLKDIVN_DVSEN;
clkdiv |= dvs;
__raw_writel(clkdiv, S3C2410_CLKDIVN);
local_irq_restore(flags);
return 0;
}
static struct clk clk_armclk = {
.name = "armclk",
.id = -1,
.parent = &clk_msysclk,
.set_parent = s3c2412_setparent_armclk,
};
/* these next clocks have an divider immediately after them,
* so we can register them with their divider and leave out the
* intermediate clock stage
*/
static unsigned long s3c2412_roundrate_clksrc(struct clk *clk,
unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
int div;
if (rate > parent_rate)
return parent_rate;
/* note, we remove the +/- 1 calculations as they cancel out */
div = (rate / parent_rate);
if (div < 1)
div = 1;
else if (div > 16)
div = 16;
return parent_rate / div;
}
static int s3c2412_setparent_uart(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_erefclk)
clksrc &= ~S3C2412_CLKSRC_UARTCLK_MPLL;
else if (parent == &clk_mpll)
clksrc |= S3C2412_CLKSRC_UARTCLK_MPLL;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static unsigned long s3c2412_getrate_uart(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long div = __raw_readl(S3C2410_CLKDIVN);
div &= S3C2412_CLKDIVN_UARTDIV_MASK;
div >>= S3C2412_CLKDIVN_UARTDIV_SHIFT;
return parent_rate / (div + 1);
}
static int s3c2412_setrate_uart(struct clk *clk, unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long clkdivn = __raw_readl(S3C2410_CLKDIVN);
rate = s3c2412_roundrate_clksrc(clk, rate);
clkdivn &= ~S3C2412_CLKDIVN_UARTDIV_MASK;
clkdivn |= ((parent_rate / rate) - 1) << S3C2412_CLKDIVN_UARTDIV_SHIFT;
__raw_writel(clkdivn, S3C2410_CLKDIVN);
return 0;
}
static struct clk clk_uart = {
.name = "uartclk",
.id = -1,
.get_rate = s3c2412_getrate_uart,
.set_rate = s3c2412_setrate_uart,
.set_parent = s3c2412_setparent_uart,
.round_rate = s3c2412_roundrate_clksrc,
};
static int s3c2412_setparent_i2s(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_erefclk)
clksrc &= ~S3C2412_CLKSRC_I2SCLK_MPLL;
else if (parent == &clk_mpll)
clksrc |= S3C2412_CLKSRC_I2SCLK_MPLL;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static unsigned long s3c2412_getrate_i2s(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long div = __raw_readl(S3C2410_CLKDIVN);
div &= S3C2412_CLKDIVN_I2SDIV_MASK;
div >>= S3C2412_CLKDIVN_I2SDIV_SHIFT;
return parent_rate / (div + 1);
}
static int s3c2412_setrate_i2s(struct clk *clk, unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long clkdivn = __raw_readl(S3C2410_CLKDIVN);
rate = s3c2412_roundrate_clksrc(clk, rate);
clkdivn &= ~S3C2412_CLKDIVN_I2SDIV_MASK;
clkdivn |= ((parent_rate / rate) - 1) << S3C2412_CLKDIVN_I2SDIV_SHIFT;
__raw_writel(clkdivn, S3C2410_CLKDIVN);
return 0;
}
static struct clk clk_i2s = {
.name = "i2sclk",
.id = -1,
.get_rate = s3c2412_getrate_i2s,
.set_rate = s3c2412_setrate_i2s,
.set_parent = s3c2412_setparent_i2s,
.round_rate = s3c2412_roundrate_clksrc,
};
static int s3c2412_setparent_cam(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
if (parent == &clk_usysclk)
clksrc &= ~S3C2412_CLKSRC_CAMCLK_HCLK;
else if (parent == &clk_h)
clksrc |= S3C2412_CLKSRC_CAMCLK_HCLK;
else
return -EINVAL;
clk->parent = parent;
__raw_writel(clksrc, S3C2412_CLKSRC);
return 0;
}
static unsigned long s3c2412_getrate_cam(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long div = __raw_readl(S3C2410_CLKDIVN);
div &= S3C2412_CLKDIVN_CAMDIV_MASK;
div >>= S3C2412_CLKDIVN_CAMDIV_SHIFT;
return parent_rate / (div + 1);
}
static int s3c2412_setrate_cam(struct clk *clk, unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long clkdivn = __raw_readl(S3C2410_CLKDIVN);
rate = s3c2412_roundrate_clksrc(clk, rate);
clkdivn &= ~S3C2412_CLKDIVN_CAMDIV_MASK;
clkdivn |= ((parent_rate / rate) - 1) << S3C2412_CLKDIVN_CAMDIV_SHIFT;
__raw_writel(clkdivn, S3C2410_CLKDIVN);
return 0;
}
static struct clk clk_cam = {
.name = "camif-upll", /* same as 2440 name */
.id = -1,
.get_rate = s3c2412_getrate_cam,
.set_rate = s3c2412_setrate_cam,
.set_parent = s3c2412_setparent_cam,
.round_rate = s3c2412_roundrate_clksrc,
};
/* standard clock definitions */
static struct clk init_clocks_disable[] = {
{
.name = "nand",
.id = -1,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_NAND,
}, {
.name = "sdi",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_SDI,
}, {
.name = "adc",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_ADC,
}, {
.name = "i2c",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_IIC,
}, {
.name = "iis",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_IIS,
}, {
.name = "spi",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_SPI,
}
};
static struct clk init_clocks[] = {
{
.name = "dma",
.id = 0,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_DMA0,
}, {
.name = "dma",
.id = 1,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_DMA1,
}, {
.name = "dma",
.id = 2,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_DMA2,
}, {
.name = "dma",
.id = 3,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_DMA3,
}, {
.name = "lcd",
.id = -1,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_LCDC,
}, {
.name = "gpio",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_GPIO,
}, {
.name = "usb-host",
.id = -1,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_USBH,
}, {
.name = "usb-device",
.id = -1,
.parent = &clk_h,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_USBD,
}, {
.name = "timers",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_PWMT,
}, {
.name = "uart",
.id = 0,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_UART0,
}, {
.name = "uart",
.id = 1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_UART1,
}, {
.name = "uart",
.id = 2,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_UART2,
}, {
.name = "rtc",
.id = -1,
.parent = &clk_p,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_RTC,
}, {
.name = "watchdog",
.id = -1,
.parent = &clk_p,
.ctrlbit = 0,
}, {
.name = "usb-bus-gadget",
.id = -1,
.parent = &clk_usb_bus,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_USB_DEV48,
}, {
.name = "usb-bus-host",
.id = -1,
.parent = &clk_usb_bus,
.enable = s3c2412_clkcon_enable,
.ctrlbit = S3C2412_CLKCON_USB_HOST48,
}
};
/* clocks to add where we need to check their parentage */
struct clk_init {
struct clk *clk;
unsigned int bit;
struct clk *src_0;
struct clk *src_1;
};
static struct clk_init clks_src[] __initdata = {
{
.clk = &clk_usysclk,
.bit = S3C2412_CLKSRC_USBCLK_HCLK,
.src_0 = &clk_urefclk,
.src_1 = &clk_upll,
}, {
.clk = &clk_i2s,
.bit = S3C2412_CLKSRC_I2SCLK_MPLL,
.src_0 = &clk_erefclk,
.src_1 = &clk_mpll,
}, {
.clk = &clk_cam,
.bit = S3C2412_CLKSRC_CAMCLK_HCLK,
.src_0 = &clk_usysclk,
.src_1 = &clk_h,
}, {
.clk = &clk_msysclk,
.bit = S3C2412_CLKSRC_MSYSCLK_MPLL,
.src_0 = &clk_mdivclk,
.src_1 = &clk_mpll,
}, {
.clk = &clk_uart,
.bit = S3C2412_CLKSRC_UARTCLK_MPLL,
.src_0 = &clk_erefclk,
.src_1 = &clk_mpll,
}, {
.clk = &clk_usbsrc,
.bit = S3C2412_CLKSRC_USBCLK_HCLK,
.src_0 = &clk_usysclk,
.src_1 = &clk_h,
},
};
/* s3c2412_clk_initparents
*
* Initialise the parents for the clocks that we get at start-time
*/
static void __init s3c2412_clk_initparents(void)
{
unsigned long clksrc = __raw_readl(S3C2412_CLKSRC);
struct clk_init *cip = clks_src;
struct clk *src;
int ptr;
int ret;
for (ptr = 0; ptr < ARRAY_SIZE(clks_src); ptr++, cip++) {
ret = s3c24xx_register_clock(cip->clk);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
cip->clk->name, ret);
}
src = (clksrc & cip->bit) ? cip->src_1 : cip->src_0;
printk(KERN_INFO "%s: parent %s\n", cip->clk->name, src->name);
clk_set_parent(cip->clk, src);
}
}
/* clocks to add straight away */
static struct clk *clks[] __initdata = {
&clk_ext,
&clk_usb_bus,
&clk_erefclk,
&clk_urefclk,
&clk_mrefclk,
&clk_armclk,
};
int __init s3c2412_baseclk_add(void)
{
unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
unsigned int dvs;
struct clk *clkp;
int ret;
int ptr;
clk_upll.enable = s3c2412_upll_enable;
clk_usb_bus.parent = &clk_usbsrc;
clk_usb_bus.rate = 0x0;
clk_f.parent = &clk_msysclk;
s3c2412_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);
}
}
/* set the dvs state according to what we got at boot time */
dvs = __raw_readl(S3C2410_CLKDIVN) & S3C2412_CLKDIVN_DVSEN;
if (dvs)
clk_armclk.parent = &clk_h;
printk(KERN_INFO "S3C2412: DVS is %s\n", dvs ? "on" : "off");
/* ensure usb bus clock is within correct rate of 48MHz */
if (clk_get_rate(&clk_usb_bus) != (48 * 1000 * 1000)) {
printk(KERN_INFO "Warning: USB bus clock not at 48MHz\n");
/* for the moment, let's use the UPLL, and see if we can
* get 48MHz */
clk_set_parent(&clk_usysclk, &clk_upll);
clk_set_parent(&clk_usbsrc, &clk_usysclk);
clk_set_rate(&clk_usbsrc, 48*1000*1000);
}
printk("S3C2412: upll %s, %ld.%03ld MHz, usb-bus %ld.%03ld MHz\n",
(__raw_readl(S3C2410_UPLLCON) & S3C2412_PLLCON_OFF) ? "off":"on",
print_mhz(clk_get_rate(&clk_upll)),
print_mhz(clk_get_rate(&clk_usb_bus)));
/* register clocks from clock array */
clkp = init_clocks;
for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
/* ensure that we note the clock state */
clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
}
/* 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);
}
s3c2412_clkcon_enable(clkp, 0);
}
return 0;
}
