diff options
Diffstat (limited to 'arch/arm/mach-imx/clock.c')
| -rw-r--r-- | arch/arm/mach-imx/clock.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/clock.c b/arch/arm/mach-imx/clock.c new file mode 100644 index 00000000000..6a90fe5578d --- /dev/null +++ b/arch/arm/mach-imx/clock.c @@ -0,0 +1,205 @@ +/* + * Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix + * + * 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/kernel.h> +#include <linux/device.h> +#include <linux/list.h> +#include <linux/math64.h> +#include <linux/err.h> + +#include <asm/io.h> +#include <asm/arch/imx-regs.h> + +/* + * Very simple approach: We can't disable clocks, so we do + * not need refcounting + */ + +struct clk { + struct list_head node; + const char *name; + unsigned long (*get_rate)(void); +}; + +/* + * get the system pll clock in Hz + * + * mfi + mfn / (mfd +1) + * f = 2 * f_ref * -------------------- + * pd + 1 + */ +static unsigned long imx_decode_pll(unsigned int pll, u32 f_ref) +{ + unsigned long long ll; + unsigned long quot; + + u32 mfi = (pll >> 10) & 0xf; + u32 mfn = pll & 0x3ff; + u32 mfd = (pll >> 16) & 0x3ff; + u32 pd = (pll >> 26) & 0xf; + + mfi = mfi <= 5 ? 5 : mfi; + + ll = 2 * (unsigned long long)f_ref * + ((mfi << 16) + (mfn << 16) / (mfd + 1)); + quot = (pd + 1) * (1 << 16); + ll += quot / 2; + do_div(ll, quot); + return (unsigned long)ll; +} + +static unsigned long imx_get_system_clk(void) +{ + u32 f_ref = (CSCR & CSCR_SYSTEM_SEL) ? 16000000 : (CLK32 * 512); + + return imx_decode_pll(SPCTL0, f_ref); +} + +static unsigned long imx_get_mcu_clk(void) +{ + return imx_decode_pll(MPCTL0, CLK32 * 512); +} + +/* + * get peripheral clock 1 ( UART[12], Timer[12], PWM ) + */ +static unsigned long imx_get_perclk1(void) +{ + return imx_get_system_clk() / (((PCDR) & 0xf)+1); +} + +/* + * get peripheral clock 2 ( LCD, SD, SPI[12] ) + */ +static unsigned long imx_get_perclk2(void) +{ + return imx_get_system_clk() / (((PCDR>>4) & 0xf)+1); +} + +/* + * get peripheral clock 3 ( SSI ) + */ +static unsigned long imx_get_perclk3(void) +{ + return imx_get_system_clk() / (((PCDR>>16) & 0x7f)+1); +} + +/* + * get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA ) + */ +static unsigned long imx_get_hclk(void) +{ + return imx_get_system_clk() / (((CSCR>>10) & 0xf)+1); +} + +static struct clk clk_system_clk = { + .name = "system_clk", + .get_rate = imx_get_system_clk, +}; + +static struct clk clk_hclk = { + .name = "hclk", + .get_rate = imx_get_hclk, +}; + +static struct clk clk_mcu_clk = { + .name = "mcu_clk", + .get_rate = imx_get_mcu_clk, +}; + +static struct clk clk_perclk1 = { + .name = "perclk1", + .get_rate = imx_get_perclk1, +}; + +static struct clk clk_uart_clk = { + .name = "uart_clk", + .get_rate = imx_get_perclk1, +}; + +static struct clk clk_perclk2 = { + .name = "perclk2", + .get_rate = imx_get_perclk2, +}; + +static struct clk clk_perclk3 = { + .name = "perclk3", + .get_rate = imx_get_perclk3, +}; + +static struct clk *clks[] = { + &clk_perclk1, + &clk_perclk2, + &clk_perclk3, + &clk_system_clk, + &clk_hclk, + &clk_mcu_clk, + &clk_uart_clk, +}; + +static LIST_HEAD(clocks); +static DEFINE_MUTEX(clocks_mutex); + +struct clk *clk_get(struct device *dev, const char *id) +{ + struct clk *p, *clk = ERR_PTR(-ENOENT); + + mutex_lock(&clocks_mutex); + list_for_each_entry(p, &clocks, node) { + if (!strcmp(p->name, id)) { + clk = p; + goto found; + } + } + +found: + mutex_unlock(&clocks_mutex); + + return clk; +} + +void clk_put(struct clk *clk) +{ +} + +int clk_enable(struct clk *clk) +{ + return 0; +} + +void clk_disable(struct clk *clk) +{ +} + +unsigned long clk_get_rate(struct clk *clk) +{ + return clk->get_rate(); +} + +int imx_clocks_init(void) +{ + int i; + + mutex_lock(&clocks_mutex); + for (i = 0; i < ARRAY_SIZE(clks); i++) + list_add(&clks[i]->node, &clocks); + mutex_unlock(&clocks_mutex); + + return 0; +} + |