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Diffstat (limited to 'arch/mips/ath25/ar2315.c')
| -rw-r--r-- | arch/mips/ath25/ar2315.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/mips/ath25/ar2315.c b/arch/mips/ath25/ar2315.c new file mode 100644 index 000000000000..828943212f03 --- /dev/null +++ b/arch/mips/ath25/ar2315.c @@ -0,0 +1,155 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2003 Atheros Communications, Inc., All Rights Reserved. + * Copyright (C) 2006 FON Technology, SL. + * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org> + * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org> + * Copyright (C) 2012 Alexandros C. Couloumbis <alex@ozo.com> + */ + +/* + * Platform devices for Atheros AR2315 SoCs + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/reboot.h> +#include <asm/bootinfo.h> +#include <asm/reboot.h> +#include <asm/time.h> + +#include "devices.h" +#include "ar2315.h" +#include "ar2315_regs.h" + +static void __iomem *ar2315_rst_base; + +static inline u32 ar2315_rst_reg_read(u32 reg) +{ + return __raw_readl(ar2315_rst_base + reg); +} + +static inline void ar2315_rst_reg_write(u32 reg, u32 val) +{ + __raw_writel(val, ar2315_rst_base + reg); +} + +static inline void ar2315_rst_reg_mask(u32 reg, u32 mask, u32 val) +{ + u32 ret = ar2315_rst_reg_read(reg); + + ret &= ~mask; + ret |= val; + ar2315_rst_reg_write(reg, ret); +} + +static void ar2315_restart(char *command) +{ + void (*mips_reset_vec)(void) = (void *)0xbfc00000; + + local_irq_disable(); + + /* try reset the system via reset control */ + ar2315_rst_reg_write(AR2315_COLD_RESET, AR2317_RESET_SYSTEM); + + /* Cold reset does not work on the AR2315/6, use the GPIO reset bits + * a workaround. Give it some time to attempt a gpio based hardware + * reset (atheros reference design workaround) */ + + /* TODO: implement the GPIO reset workaround */ + + /* Some boards (e.g. Senao EOC-2610) don't implement the reset logic + * workaround. Attempt to jump to the mips reset location - + * the boot loader itself might be able to recover the system */ + mips_reset_vec(); +} + +/* + * This table is indexed by bits 5..4 of the CLOCKCTL1 register + * to determine the predevisor value. + */ +static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 }; +static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 }; + +static unsigned __init ar2315_sys_clk(u32 clock_ctl) +{ + unsigned int pllc_ctrl, cpu_div; + unsigned int pllc_out, refdiv, fdiv, divby2; + unsigned int clk_div; + + pllc_ctrl = ar2315_rst_reg_read(AR2315_PLLC_CTL); + refdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_REF_DIV); + refdiv = clockctl1_predivide_table[refdiv]; + fdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_FDBACK_DIV); + divby2 = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_ADD_FDBACK_DIV) + 1; + pllc_out = (40000000 / refdiv) * (2 * divby2) * fdiv; + + /* clkm input selected */ + switch (clock_ctl & AR2315_CPUCLK_CLK_SEL_M) { + case 0: + case 1: + clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKM_DIV); + clk_div = pllc_divide_table[clk_div]; + break; + case 2: + clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKC_DIV); + clk_div = pllc_divide_table[clk_div]; + break; + default: + pllc_out = 40000000; + clk_div = 1; + break; + } + + cpu_div = ATH25_REG_MS(clock_ctl, AR2315_CPUCLK_CLK_DIV); + cpu_div = cpu_div * 2 ?: 1; + + return pllc_out / (clk_div * cpu_div); +} + +static inline unsigned ar2315_cpu_frequency(void) +{ + return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK)); +} + +static inline unsigned ar2315_apb_frequency(void) +{ + return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK)); +} + +void __init ar2315_plat_time_init(void) +{ + mips_hpt_frequency = ar2315_cpu_frequency() / 2; +} + +void __init ar2315_plat_mem_setup(void) +{ + void __iomem *sdram_base; + u32 memsize, memcfg; + u32 config; + + /* Detect memory size */ + sdram_base = ioremap_nocache(AR2315_SDRAMCTL_BASE, + AR2315_SDRAMCTL_SIZE); + memcfg = __raw_readl(sdram_base + AR2315_MEM_CFG); + memsize = 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_DATA_WIDTH); + memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_COL_WIDTH); + memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_ROW_WIDTH); + memsize <<= 3; + add_memory_region(0, memsize, BOOT_MEM_RAM); + iounmap(sdram_base); + + ar2315_rst_base = ioremap_nocache(AR2315_RST_BASE, AR2315_RST_SIZE); + + /* Clear any lingering AHB errors */ + config = read_c0_config(); + write_c0_config(config & ~0x3); + ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET); + ar2315_rst_reg_read(AR2315_AHB_ERR1); + ar2315_rst_reg_write(AR2315_WDT_CTRL, AR2315_WDT_CTRL_IGNORE); + + _machine_restart = ar2315_restart; +} |