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linux/arch/mips/ralink/mt7620.c
Gabor Juhos ded1e9d727 MIPS: ralink: mt7620: Improve clock frequency detection 
The current code assumes that the peripheral clock always
runs at 40MHz which is not true in all configuration. The
peripheral clock can also use the reference clock instead
of the fixed 40MHz rate. If the reference clock runs at a
different rate, various peripheries are behaving incorrectly.

Additionally, the currectly calculated system clock is also
wrong. The actual value what the code computes is the rate
of the DRAM which can be different from the system clock.

Add new helper functions to get the rate of the different
clocks and use the correct values for the registered clock
devices.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-09-04 16:57:05 +02:00

387 lines
8.6 KiB
C
Raw Blame History

/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* Parts of this file are based on Ralink's 2.6.21 BSP
*
* Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
* Copyright (C) 2013 John Crispin <blogic@openwrt.org>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <asm/mipsregs.h>
#include <asm/mach-ralink/ralink_regs.h>
#include <asm/mach-ralink/mt7620.h>
#include "common.h"
/* does the board have sdram or ddram */
static int dram_type;
static struct ralink_pinmux_grp mode_mux[] = {
{
.name = "i2c",
.mask = MT7620_GPIO_MODE_I2C,
.gpio_first = 1,
.gpio_last = 2,
}, {
.name = "spi",
.mask = MT7620_GPIO_MODE_SPI,
.gpio_first = 3,
.gpio_last = 6,
}, {
.name = "uartlite",
.mask = MT7620_GPIO_MODE_UART1,
.gpio_first = 15,
.gpio_last = 16,
}, {
.name = "wdt",
.mask = MT7620_GPIO_MODE_WDT,
.gpio_first = 17,
.gpio_last = 17,
}, {
.name = "mdio",
.mask = MT7620_GPIO_MODE_MDIO,
.gpio_first = 22,
.gpio_last = 23,
}, {
.name = "rgmii1",
.mask = MT7620_GPIO_MODE_RGMII1,
.gpio_first = 24,
.gpio_last = 35,
}, {
.name = "spi refclk",
.mask = MT7620_GPIO_MODE_SPI_REF_CLK,
.gpio_first = 37,
.gpio_last = 39,
}, {
.name = "jtag",
.mask = MT7620_GPIO_MODE_JTAG,
.gpio_first = 40,
.gpio_last = 44,
}, {
/* shared lines with jtag */
.name = "ephy",
.mask = MT7620_GPIO_MODE_EPHY,
.gpio_first = 40,
.gpio_last = 44,
}, {
.name = "nand",
.mask = MT7620_GPIO_MODE_JTAG,
.gpio_first = 45,
.gpio_last = 59,
}, {
.name = "rgmii2",
.mask = MT7620_GPIO_MODE_RGMII2,
.gpio_first = 60,
.gpio_last = 71,
}, {
.name = "wled",
.mask = MT7620_GPIO_MODE_WLED,
.gpio_first = 72,
.gpio_last = 72,
}, {0}
};
static struct ralink_pinmux_grp uart_mux[] = {
{
.name = "uartf",
.mask = MT7620_GPIO_MODE_UARTF,
.gpio_first = 7,
.gpio_last = 14,
}, {
.name = "pcm uartf",
.mask = MT7620_GPIO_MODE_PCM_UARTF,
.gpio_first = 7,
.gpio_last = 14,
}, {
.name = "pcm i2s",
.mask = MT7620_GPIO_MODE_PCM_I2S,
.gpio_first = 7,
.gpio_last = 14,
}, {
.name = "i2s uartf",
.mask = MT7620_GPIO_MODE_I2S_UARTF,
.gpio_first = 7,
.gpio_last = 14,
}, {
.name = "pcm gpio",
.mask = MT7620_GPIO_MODE_PCM_GPIO,
.gpio_first = 11,
.gpio_last = 14,
}, {
.name = "gpio uartf",
.mask = MT7620_GPIO_MODE_GPIO_UARTF,
.gpio_first = 7,
.gpio_last = 10,
}, {
.name = "gpio i2s",
.mask = MT7620_GPIO_MODE_GPIO_I2S,
.gpio_first = 7,
.gpio_last = 10,
}, {
.name = "gpio",
.mask = MT7620_GPIO_MODE_GPIO,
}, {0}
};
struct ralink_pinmux rt_gpio_pinmux = {
.mode = mode_mux,
.uart = uart_mux,
.uart_shift = MT7620_GPIO_MODE_UART0_SHIFT,
.uart_mask = MT7620_GPIO_MODE_UART0_MASK,
};
static __init u32
mt7620_calc_rate(u32 ref_rate, u32 mul, u32 div)
{
u64 t;
t = ref_rate;
t *= mul;
do_div(t, div);
return t;
}
#define MHZ(x) ((x) * 1000 * 1000)
static __init unsigned long
mt7620_get_xtal_rate(void)
{
u32 reg;
reg = rt_sysc_r32(SYSC_REG_SYSTEM_CONFIG0);
if (reg & SYSCFG0_XTAL_FREQ_SEL)
return MHZ(40);
return MHZ(20);
}
static __init unsigned long
mt7620_get_periph_rate(unsigned long xtal_rate)
{
u32 reg;
reg = rt_sysc_r32(SYSC_REG_CLKCFG0);
if (reg & CLKCFG0_PERI_CLK_SEL)
return xtal_rate;
return MHZ(40);
}
static const u32 mt7620_clk_divider[] __initconst = { 2, 3, 4, 8 };
static __init unsigned long
mt7620_get_cpu_pll_rate(unsigned long xtal_rate)
{
u32 reg;
u32 mul;
u32 div;
reg = rt_sysc_r32(SYSC_REG_CPLL_CONFIG0);
if (reg & CPLL_CFG0_BYPASS_REF_CLK)
return xtal_rate;
if ((reg & CPLL_CFG0_SW_CFG) == 0)
return MHZ(600);
mul = (reg >> CPLL_CFG0_PLL_MULT_RATIO_SHIFT) &
CPLL_CFG0_PLL_MULT_RATIO_MASK;
mul += 24;
if (reg & CPLL_CFG0_LC_CURFCK)
mul *= 2;
div = (reg >> CPLL_CFG0_PLL_DIV_RATIO_SHIFT) &
CPLL_CFG0_PLL_DIV_RATIO_MASK;
WARN_ON(div >= ARRAY_SIZE(mt7620_clk_divider));
return mt7620_calc_rate(xtal_rate, mul, mt7620_clk_divider[div]);
}
static __init unsigned long
mt7620_get_pll_rate(unsigned long xtal_rate, unsigned long cpu_pll_rate)
{
u32 reg;
reg = rt_sysc_r32(SYSC_REG_CPLL_CONFIG1);
if (reg & CPLL_CFG1_CPU_AUX1)
return xtal_rate;
if (reg & CPLL_CFG1_CPU_AUX0)
return MHZ(480);
return cpu_pll_rate;
}
static __init unsigned long
mt7620_get_cpu_rate(unsigned long pll_rate)
{
u32 reg;
u32 mul;
u32 div;
reg = rt_sysc_r32(SYSC_REG_CPU_SYS_CLKCFG);
mul = reg & CPU_SYS_CLKCFG_CPU_FFRAC_MASK;
div = (reg >> CPU_SYS_CLKCFG_CPU_FDIV_SHIFT) &
CPU_SYS_CLKCFG_CPU_FDIV_MASK;
return mt7620_calc_rate(pll_rate, mul, div);
}
static const u32 mt7620_ocp_dividers[16] __initconst = {
[CPU_SYS_CLKCFG_OCP_RATIO_2] = 2,
[CPU_SYS_CLKCFG_OCP_RATIO_3] = 3,
[CPU_SYS_CLKCFG_OCP_RATIO_4] = 4,
[CPU_SYS_CLKCFG_OCP_RATIO_5] = 5,
[CPU_SYS_CLKCFG_OCP_RATIO_10] = 10,
};
static __init unsigned long
mt7620_get_dram_rate(unsigned long pll_rate)
{
if (dram_type == SYSCFG0_DRAM_TYPE_SDRAM)
return pll_rate / 4;
return pll_rate / 3;
}
static __init unsigned long
mt7620_get_sys_rate(unsigned long cpu_rate)
{
u32 reg;
u32 ocp_ratio;
u32 div;
reg = rt_sysc_r32(SYSC_REG_CPU_SYS_CLKCFG);
ocp_ratio = (reg >> CPU_SYS_CLKCFG_OCP_RATIO_SHIFT) &
CPU_SYS_CLKCFG_OCP_RATIO_MASK;
if (WARN_ON(ocp_ratio >= ARRAY_SIZE(mt7620_ocp_dividers)))
return cpu_rate;
div = mt7620_ocp_dividers[ocp_ratio];
if (WARN(!div, "invalid divider for OCP ratio %u", ocp_ratio))
return cpu_rate;
return cpu_rate / div;
}
void __init ralink_clk_init(void)
{
unsigned long xtal_rate;
unsigned long cpu_pll_rate;
unsigned long pll_rate;
unsigned long cpu_rate;
unsigned long sys_rate;
unsigned long dram_rate;
unsigned long periph_rate;
xtal_rate = mt7620_get_xtal_rate();
cpu_pll_rate = mt7620_get_cpu_pll_rate(xtal_rate);
pll_rate = mt7620_get_pll_rate(xtal_rate, cpu_pll_rate);
cpu_rate = mt7620_get_cpu_rate(pll_rate);
dram_rate = mt7620_get_dram_rate(pll_rate);
sys_rate = mt7620_get_sys_rate(cpu_rate);
periph_rate = mt7620_get_periph_rate(xtal_rate);
#define RFMT(label) label ":%lu.%03luMHz "
#define RINT(x) ((x) / 1000000)
#define RFRAC(x) (((x) / 1000) % 1000)
pr_debug(RFMT("XTAL") RFMT("CPU_PLL") RFMT("PLL"),
RINT(xtal_rate), RFRAC(xtal_rate),
RINT(cpu_pll_rate), RFRAC(cpu_pll_rate),
RINT(pll_rate), RFRAC(pll_rate));
pr_debug(RFMT("CPU") RFMT("DRAM") RFMT("SYS") RFMT("PERIPH"),
RINT(cpu_rate), RFRAC(cpu_rate),
RINT(dram_rate), RFRAC(dram_rate),
RINT(sys_rate), RFRAC(sys_rate),
RINT(periph_rate), RFRAC(periph_rate));
#undef RFRAC
#undef RINT
#undef RFMT
ralink_clk_add("cpu", cpu_rate);
ralink_clk_add("10000100.timer", periph_rate);
ralink_clk_add("10000500.uart", periph_rate);
ralink_clk_add("10000c00.uartlite", periph_rate);
}
void __init ralink_of_remap(void)
{
rt_sysc_membase = plat_of_remap_node("ralink,mt7620a-sysc");
rt_memc_membase = plat_of_remap_node("ralink,mt7620a-memc");
if (!rt_sysc_membase || !rt_memc_membase)
panic("Failed to remap core resources");
}
void prom_soc_init(struct ralink_soc_info *soc_info)
{
void __iomem *sysc = (void __iomem *) KSEG1ADDR(MT7620_SYSC_BASE);
unsigned char *name = NULL;
u32 n0;
u32 n1;
u32 rev;
u32 cfg0;
n0 = __raw_readl(sysc + SYSC_REG_CHIP_NAME0);
n1 = __raw_readl(sysc + SYSC_REG_CHIP_NAME1);
if (n0 == MT7620N_CHIP_NAME0 && n1 == MT7620N_CHIP_NAME1) {
name = "MT7620N";
soc_info->compatible = "ralink,mt7620n-soc";
} else if (n0 == MT7620A_CHIP_NAME0 && n1 == MT7620A_CHIP_NAME1) {
name = "MT7620A";
soc_info->compatible = "ralink,mt7620a-soc";
} else {
panic("mt7620: unknown SoC, n0:%08x n1:%08x\n", n0, n1);
}
rev = __raw_readl(sysc + SYSC_REG_CHIP_REV);
snprintf(soc_info->sys_type, RAMIPS_SYS_TYPE_LEN,
"Ralink %s ver:%u eco:%u",
name,
(rev >> CHIP_REV_VER_SHIFT) & CHIP_REV_VER_MASK,
(rev & CHIP_REV_ECO_MASK));
cfg0 = __raw_readl(sysc + SYSC_REG_SYSTEM_CONFIG0);
dram_type = (cfg0 >> SYSCFG0_DRAM_TYPE_SHIFT) & SYSCFG0_DRAM_TYPE_MASK;
switch (dram_type) {
case SYSCFG0_DRAM_TYPE_SDRAM:
pr_info("Board has SDRAM\n");
soc_info->mem_size_min = MT7620_SDRAM_SIZE_MIN;
soc_info->mem_size_max = MT7620_SDRAM_SIZE_MAX;
break;
case SYSCFG0_DRAM_TYPE_DDR1:
pr_info("Board has DDR1\n");
soc_info->mem_size_min = MT7620_DDR1_SIZE_MIN;
soc_info->mem_size_max = MT7620_DDR1_SIZE_MAX;
break;
case SYSCFG0_DRAM_TYPE_DDR2:
pr_info("Board has DDR2\n");
soc_info->mem_size_min = MT7620_DDR2_SIZE_MIN;
soc_info->mem_size_max = MT7620_DDR2_SIZE_MAX;
break;
default:
BUG();
}
soc_info->mem_base = MT7620_DRAM_BASE;
}
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