diff options
Diffstat (limited to 'arch/arm/mach-s3c2412/clock.c')
| -rw-r--r-- | arch/arm/mach-s3c2412/clock.c | 716 |
1 files changed, 716 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2412/clock.c b/arch/arm/mach-s3c2412/clock.c new file mode 100644 index 000000000000..6a8e4448770b --- /dev/null +++ b/arch/arm/mach-s3c2412/clock.c @@ -0,0 +1,716 @@ +/* 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/arch/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_upll) + 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, +}; + +/* 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, +}; + +int __init s3c2412_baseclk_add(void) +{ + unsigned long clkcon = __raw_readl(S3C2410_CLKCON); + struct clk *clkp; + int ret; + int ptr; + + clk_upll.enable = s3c2412_upll_enable; + clk_usb_bus.parent = &clk_usbsrc; + clk_usb_bus.rate = 0x0; + + 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); + } + } + + /* 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 subsytems 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; +} |