linux/arch/mips/ath25/ar5312.c
Sergey Ryazanov 3b12308f33 MIPS: ath25: add basic AR5312 SoC support
Add basic support for Atheros AR5312/AR2312 SoCs: registers definition
file and initial setup code.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8238/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:26 +01:00

156 lines
4.4 KiB
C

/*
* 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) 2006-2009 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2012 Alexandros C. Couloumbis <alex@ozo.com>
*/
/*
* Platform devices for Atheros AR5312 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 "ar5312.h"
#include "ar5312_regs.h"
static void __iomem *ar5312_rst_base;
static inline u32 ar5312_rst_reg_read(u32 reg)
{
return __raw_readl(ar5312_rst_base + reg);
}
static inline void ar5312_rst_reg_write(u32 reg, u32 val)
{
__raw_writel(val, ar5312_rst_base + reg);
}
static inline void ar5312_rst_reg_mask(u32 reg, u32 mask, u32 val)
{
u32 ret = ar5312_rst_reg_read(reg);
ret &= ~mask;
ret |= val;
ar5312_rst_reg_write(reg, ret);
}
static void ar5312_restart(char *command)
{
/* reset the system */
local_irq_disable();
while (1)
ar5312_rst_reg_write(AR5312_RESET, AR5312_RESET_SYSTEM);
}
/*
* This table is indexed by bits 5..4 of the CLOCKCTL1 register
* to determine the predevisor value.
*/
static unsigned clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
static unsigned __init ar5312_cpu_frequency(void)
{
u32 scratch, devid, clock_ctl1;
u32 predivide_mask, multiplier_mask, doubler_mask;
unsigned predivide_shift, multiplier_shift;
unsigned predivide_select, predivisor, multiplier;
/* Trust the bootrom's idea of cpu frequency. */
scratch = ar5312_rst_reg_read(AR5312_SCRATCH);
if (scratch)
return scratch;
devid = ar5312_rst_reg_read(AR5312_REV);
devid = (devid & AR5312_REV_MAJ) >> AR5312_REV_MAJ_S;
if (devid == AR5312_REV_MAJ_AR2313) {
predivide_mask = AR2313_CLOCKCTL1_PREDIVIDE_MASK;
predivide_shift = AR2313_CLOCKCTL1_PREDIVIDE_SHIFT;
multiplier_mask = AR2313_CLOCKCTL1_MULTIPLIER_MASK;
multiplier_shift = AR2313_CLOCKCTL1_MULTIPLIER_SHIFT;
doubler_mask = AR2313_CLOCKCTL1_DOUBLER_MASK;
} else { /* AR5312 and AR2312 */
predivide_mask = AR5312_CLOCKCTL1_PREDIVIDE_MASK;
predivide_shift = AR5312_CLOCKCTL1_PREDIVIDE_SHIFT;
multiplier_mask = AR5312_CLOCKCTL1_MULTIPLIER_MASK;
multiplier_shift = AR5312_CLOCKCTL1_MULTIPLIER_SHIFT;
doubler_mask = AR5312_CLOCKCTL1_DOUBLER_MASK;
}
/*
* Clocking is derived from a fixed 40MHz input clock.
*
* cpu_freq = input_clock * MULT (where MULT is PLL multiplier)
* sys_freq = cpu_freq / 4 (used for APB clock, serial,
* flash, Timer, Watchdog Timer)
*
* cnt_freq = cpu_freq / 2 (use for CPU count/compare)
*
* So, for example, with a PLL multiplier of 5, we have
*
* cpu_freq = 200MHz
* sys_freq = 50MHz
* cnt_freq = 100MHz
*
* We compute the CPU frequency, based on PLL settings.
*/
clock_ctl1 = ar5312_rst_reg_read(AR5312_CLOCKCTL1);
predivide_select = (clock_ctl1 & predivide_mask) >> predivide_shift;
predivisor = clockctl1_predivide_table[predivide_select];
multiplier = (clock_ctl1 & multiplier_mask) >> multiplier_shift;
if (clock_ctl1 & doubler_mask)
multiplier <<= 1;
return (40000000 / predivisor) * multiplier;
}
static inline unsigned ar5312_sys_frequency(void)
{
return ar5312_cpu_frequency() / 4;
}
void __init ar5312_plat_time_init(void)
{
mips_hpt_frequency = ar5312_cpu_frequency() / 2;
}
void __init ar5312_plat_mem_setup(void)
{
void __iomem *sdram_base;
u32 memsize, memcfg, bank0_ac, bank1_ac;
/* Detect memory size */
sdram_base = ioremap_nocache(AR5312_SDRAMCTL_BASE,
AR5312_SDRAMCTL_SIZE);
memcfg = __raw_readl(sdram_base + AR5312_MEM_CFG1);
bank0_ac = ATH25_REG_MS(memcfg, AR5312_MEM_CFG1_AC0);
bank1_ac = ATH25_REG_MS(memcfg, AR5312_MEM_CFG1_AC1);
memsize = (bank0_ac ? (1 << (bank0_ac + 1)) : 0) +
(bank1_ac ? (1 << (bank1_ac + 1)) : 0);
memsize <<= 20;
add_memory_region(0, memsize, BOOT_MEM_RAM);
iounmap(sdram_base);
ar5312_rst_base = ioremap_nocache(AR5312_RST_BASE, AR5312_RST_SIZE);
/* Clear any lingering AHB errors */
ar5312_rst_reg_read(AR5312_PROCADDR);
ar5312_rst_reg_read(AR5312_DMAADDR);
ar5312_rst_reg_write(AR5312_WDT_CTRL, AR5312_WDT_CTRL_IGNORE);
_machine_restart = ar5312_restart;
}