diff options
Diffstat (limited to 'arch/arm/mach-shmobile/clock-emev2.c')
| -rw-r--r-- | arch/arm/mach-shmobile/clock-emev2.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/clock-emev2.c b/arch/arm/mach-shmobile/clock-emev2.c new file mode 100644 index 00000000000..4710f1847bb --- /dev/null +++ b/arch/arm/mach-shmobile/clock-emev2.c @@ -0,0 +1,249 @@ +/* + * Emma Mobile EV2 clock framework support + * + * Copyright (C) 2012 Magnus Damm + * + * 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; version 2 of the License. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/sh_clk.h> +#include <linux/clkdev.h> +#include <mach/common.h> + +#define EMEV2_SMU_BASE 0xe0110000 + +/* EMEV2 SMU registers */ +#define USIAU0_RSTCTRL 0x094 +#define USIBU1_RSTCTRL 0x0ac +#define USIBU2_RSTCTRL 0x0b0 +#define USIBU3_RSTCTRL 0x0b4 +#define STI_RSTCTRL 0x124 +#define USIAU0GCLKCTRL 0x4a0 +#define USIBU1GCLKCTRL 0x4b8 +#define USIBU2GCLKCTRL 0x4bc +#define USIBU3GCLKCTRL 0x04c0 +#define STIGCLKCTRL 0x528 +#define USIAU0SCLKDIV 0x61c +#define USIB2SCLKDIV 0x65c +#define USIB3SCLKDIV 0x660 +#define STI_CLKSEL 0x688 +#define SMU_GENERAL_REG0 0x7c0 + +/* not pretty, but hey */ +static void __iomem *smu_base; + +static void emev2_smu_write(unsigned long value, int offs) +{ + BUG_ON(!smu_base || (offs >= PAGE_SIZE)); + iowrite32(value, smu_base + offs); +} + +void emev2_set_boot_vector(unsigned long value) +{ + emev2_smu_write(value, SMU_GENERAL_REG0); +} + +static struct clk_mapping smu_mapping = { + .phys = EMEV2_SMU_BASE, + .len = PAGE_SIZE, +}; + +/* Fixed 32 KHz root clock from C32K pin */ +static struct clk c32k_clk = { + .rate = 32768, + .mapping = &smu_mapping, +}; + +/* PLL3 multiplies C32K with 7000 */ +static unsigned long pll3_recalc(struct clk *clk) +{ + return clk->parent->rate * 7000; +} + +static struct sh_clk_ops pll3_clk_ops = { + .recalc = pll3_recalc, +}; + +static struct clk pll3_clk = { + .ops = &pll3_clk_ops, + .parent = &c32k_clk, +}; + +static struct clk *main_clks[] = { + &c32k_clk, + &pll3_clk, +}; + +enum { SCLKDIV_USIAU0, SCLKDIV_USIBU2, SCLKDIV_USIBU1, SCLKDIV_USIBU3, + SCLKDIV_NR }; + +#define SCLKDIV(_reg, _shift) \ +{ \ + .parent = &pll3_clk, \ + .enable_reg = IOMEM(EMEV2_SMU_BASE + (_reg)), \ + .enable_bit = _shift, \ +} + +static struct clk sclkdiv_clks[SCLKDIV_NR] = { + [SCLKDIV_USIAU0] = SCLKDIV(USIAU0SCLKDIV, 0), + [SCLKDIV_USIBU2] = SCLKDIV(USIB2SCLKDIV, 16), + [SCLKDIV_USIBU1] = SCLKDIV(USIB2SCLKDIV, 0), + [SCLKDIV_USIBU3] = SCLKDIV(USIB3SCLKDIV, 0), +}; + +enum { GCLK_USIAU0_SCLK, GCLK_USIBU1_SCLK, GCLK_USIBU2_SCLK, GCLK_USIBU3_SCLK, + GCLK_STI_SCLK, + GCLK_NR }; + +#define GCLK_SCLK(_parent, _reg) \ +{ \ + .parent = _parent, \ + .enable_reg = IOMEM(EMEV2_SMU_BASE + (_reg)), \ + .enable_bit = 1, /* SCLK_GCC */ \ +} + +static struct clk gclk_clks[GCLK_NR] = { + [GCLK_USIAU0_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIAU0], + USIAU0GCLKCTRL), + [GCLK_USIBU1_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU1], + USIBU1GCLKCTRL), + [GCLK_USIBU2_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU2], + USIBU2GCLKCTRL), + [GCLK_USIBU3_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU3], + USIBU3GCLKCTRL), + [GCLK_STI_SCLK] = GCLK_SCLK(&c32k_clk, STIGCLKCTRL), +}; + +static int emev2_gclk_enable(struct clk *clk) +{ + iowrite32(ioread32(clk->mapped_reg) | (1 << clk->enable_bit), + clk->mapped_reg); + return 0; +} + +static void emev2_gclk_disable(struct clk *clk) +{ + iowrite32(ioread32(clk->mapped_reg) & ~(1 << clk->enable_bit), + clk->mapped_reg); +} + +static struct sh_clk_ops emev2_gclk_clk_ops = { + .enable = emev2_gclk_enable, + .disable = emev2_gclk_disable, + .recalc = followparent_recalc, +}; + +static int __init emev2_gclk_register(struct clk *clks, int nr) +{ + struct clk *clkp; + int ret = 0; + int k; + + for (k = 0; !ret && (k < nr); k++) { + clkp = clks + k; + clkp->ops = &emev2_gclk_clk_ops; + ret |= clk_register(clkp); + } + + return ret; +} + +static unsigned long emev2_sclkdiv_recalc(struct clk *clk) +{ + unsigned int sclk_div; + + sclk_div = (ioread32(clk->mapped_reg) >> clk->enable_bit) & 0xff; + + return clk->parent->rate / (sclk_div + 1); +} + +static struct sh_clk_ops emev2_sclkdiv_clk_ops = { + .recalc = emev2_sclkdiv_recalc, +}; + +static int __init emev2_sclkdiv_register(struct clk *clks, int nr) +{ + struct clk *clkp; + int ret = 0; + int k; + + for (k = 0; !ret && (k < nr); k++) { + clkp = clks + k; + clkp->ops = &emev2_sclkdiv_clk_ops; + ret |= clk_register(clkp); + } + + return ret; +} + +static struct clk_lookup lookups[] = { + CLKDEV_DEV_ID("serial8250-em.0", &gclk_clks[GCLK_USIAU0_SCLK]), + CLKDEV_DEV_ID("e1020000.uart", &gclk_clks[GCLK_USIAU0_SCLK]), + CLKDEV_DEV_ID("serial8250-em.1", &gclk_clks[GCLK_USIBU1_SCLK]), + CLKDEV_DEV_ID("e1030000.uart", &gclk_clks[GCLK_USIBU1_SCLK]), + CLKDEV_DEV_ID("serial8250-em.2", &gclk_clks[GCLK_USIBU2_SCLK]), + CLKDEV_DEV_ID("e1040000.uart", &gclk_clks[GCLK_USIBU2_SCLK]), + CLKDEV_DEV_ID("serial8250-em.3", &gclk_clks[GCLK_USIBU3_SCLK]), + CLKDEV_DEV_ID("e1050000.uart", &gclk_clks[GCLK_USIBU3_SCLK]), + CLKDEV_DEV_ID("em_sti.0", &gclk_clks[GCLK_STI_SCLK]), + CLKDEV_DEV_ID("e0180000.sti", &gclk_clks[GCLK_STI_SCLK]), +}; + +void __init emev2_clock_init(void) +{ + int k, ret = 0; + static int is_setup; + + /* yuck, this is ugly as hell, but the non-smp case of clocks + * code is now designed to rely on ioremap() instead of static + * entity maps. in the case of smp we need access to the SMU + * register earlier than ioremap() is actually working without + * any static maps. to enable SMP in ugly but with dynamic + * mappings we have to call emev2_clock_init() from different + * places depending on UP and SMP... + */ + if (is_setup++) + return; + + smu_base = ioremap(EMEV2_SMU_BASE, PAGE_SIZE); + BUG_ON(!smu_base); + + /* setup STI timer to run on 37.768 kHz and deassert reset */ + emev2_smu_write(0, STI_CLKSEL); + emev2_smu_write(1, STI_RSTCTRL); + + /* deassert reset for UART0->UART3 */ + emev2_smu_write(2, USIAU0_RSTCTRL); + emev2_smu_write(2, USIBU1_RSTCTRL); + emev2_smu_write(2, USIBU2_RSTCTRL); + emev2_smu_write(2, USIBU3_RSTCTRL); + + for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++) + ret = clk_register(main_clks[k]); + + if (!ret) + ret = emev2_sclkdiv_register(sclkdiv_clks, SCLKDIV_NR); + + if (!ret) + ret = emev2_gclk_register(gclk_clks, GCLK_NR); + + clkdev_add_table(lookups, ARRAY_SIZE(lookups)); + + if (!ret) + shmobile_clk_init(); + else + panic("failed to setup emev2 clocks\n"); +} |