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-rw-r--r--arch/arm/mach-s3c2410/Makefile1
-rw-r--r--arch/arm/mach-s3c2410/s3c2412-clock.c711
2 files changed, 712 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2410/Makefile b/arch/arm/mach-s3c2410/Makefile
index 86219c6df32..d934a89179a 100644
--- a/arch/arm/mach-s3c2410/Makefile
+++ b/arch/arm/mach-s3c2410/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_PM_SIMTEC) += pm-simtec.o
# S3C2412 support
obj-$(CONFIG_CPU_S3C2412) += s3c2412.o
+obj-$(CONFIG_CPU_S3C2412) += s3c2412-clock.o
#
# S3C244X support
diff --git a/arch/arm/mach-s3c2410/s3c2412-clock.c b/arch/arm/mach-s3c2410/s3c2412-clock.c
new file mode 100644
index 00000000000..c95ed3e1858
--- /dev/null
+++ b/arch/arm/mach-s3c2410/s3c2412-clock.c
@@ -0,0 +1,711 @@
+/* linux/arch/arm/mach-s3c2410/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 <asm/hardware.h>
+#include <asm/io.h>
+
+#include <asm/arch/regs-clock.h>
+#include <asm/arch/regs-gpio.h>
+
+#include "clock.h"
+#include "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
+*/
+
+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;
+};
+
+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 */
+
+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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 01:51:05 +0000