linux/arch/mips/ath79/clock.c
Gabor Juhos 97541ccfb9 MIPS: ath79: Fix CPU/DDR frequency calculation for SRIF PLLs
Besides the CPU and DDR PLLs, the CPU and DDR frequencies
can be derived from other PLLs in the SRIF block on the
AR934x SoCs. The current code does not checks if the SRIF
PLLs are used and this can lead to incorrectly calculated
CPU/DDR frequencies.

Fix it by calculating the frequencies from SRIF PLLs if
those are used on a given board.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: <stable@vger.kernel.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4324/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-10-01 11:37:15 +02:00

373 lines
9.9 KiB
C

/*
* Atheros AR71XX/AR724X/AR913X common routines
*
* Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
*
* Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <asm/div64.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"
#define AR71XX_BASE_FREQ 40000000
#define AR724X_BASE_FREQ 5000000
#define AR913X_BASE_FREQ 5000000
struct clk {
unsigned long rate;
};
static struct clk ath79_ref_clk;
static struct clk ath79_cpu_clk;
static struct clk ath79_ddr_clk;
static struct clk ath79_ahb_clk;
static struct clk ath79_wdt_clk;
static struct clk ath79_uart_clk;
static void __init ar71xx_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR71XX_BASE_FREQ;
pll = ath79_pll_rr(AR71XX_PLL_REG_CPU_CONFIG);
div = ((pll >> AR71XX_PLL_DIV_SHIFT) & AR71XX_PLL_DIV_MASK) + 1;
freq = div * ath79_ref_clk.rate;
div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
ath79_cpu_clk.rate = freq / div;
div = ((pll >> AR71XX_DDR_DIV_SHIFT) & AR71XX_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
static void __init ar724x_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR724X_BASE_FREQ;
pll = ath79_pll_rr(AR724X_PLL_REG_CPU_CONFIG);
div = ((pll >> AR724X_PLL_DIV_SHIFT) & AR724X_PLL_DIV_MASK);
freq = div * ath79_ref_clk.rate;
div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK);
freq *= div;
ath79_cpu_clk.rate = freq;
div = ((pll >> AR724X_DDR_DIV_SHIFT) & AR724X_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR724X_AHB_DIV_SHIFT) & AR724X_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
static void __init ar913x_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR913X_BASE_FREQ;
pll = ath79_pll_rr(AR913X_PLL_REG_CPU_CONFIG);
div = ((pll >> AR913X_PLL_DIV_SHIFT) & AR913X_PLL_DIV_MASK);
freq = div * ath79_ref_clk.rate;
ath79_cpu_clk.rate = freq;
div = ((pll >> AR913X_DDR_DIV_SHIFT) & AR913X_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR913X_AHB_DIV_SHIFT) & AR913X_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
static void __init ar933x_clocks_init(void)
{
u32 clock_ctrl;
u32 cpu_config;
u32 freq;
u32 t;
t = ath79_reset_rr(AR933X_RESET_REG_BOOTSTRAP);
if (t & AR933X_BOOTSTRAP_REF_CLK_40)
ath79_ref_clk.rate = (40 * 1000 * 1000);
else
ath79_ref_clk.rate = (25 * 1000 * 1000);
clock_ctrl = ath79_pll_rr(AR933X_PLL_CLOCK_CTRL_REG);
if (clock_ctrl & AR933X_PLL_CLOCK_CTRL_BYPASS) {
ath79_cpu_clk.rate = ath79_ref_clk.rate;
ath79_ahb_clk.rate = ath79_ref_clk.rate;
ath79_ddr_clk.rate = ath79_ref_clk.rate;
} else {
cpu_config = ath79_pll_rr(AR933X_PLL_CPU_CONFIG_REG);
t = (cpu_config >> AR933X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
AR933X_PLL_CPU_CONFIG_REFDIV_MASK;
freq = ath79_ref_clk.rate / t;
t = (cpu_config >> AR933X_PLL_CPU_CONFIG_NINT_SHIFT) &
AR933X_PLL_CPU_CONFIG_NINT_MASK;
freq *= t;
t = (cpu_config >> AR933X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
AR933X_PLL_CPU_CONFIG_OUTDIV_MASK;
if (t == 0)
t = 1;
freq >>= t;
t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_CPU_DIV_SHIFT) &
AR933X_PLL_CLOCK_CTRL_CPU_DIV_MASK) + 1;
ath79_cpu_clk.rate = freq / t;
t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_DDR_DIV_SHIFT) &
AR933X_PLL_CLOCK_CTRL_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / t;
t = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_AHB_DIV_SHIFT) &
AR933X_PLL_CLOCK_CTRL_AHB_DIV_MASK) + 1;
ath79_ahb_clk.rate = freq / t;
}
ath79_wdt_clk.rate = ath79_ref_clk.rate;
ath79_uart_clk.rate = ath79_ref_clk.rate;
}
static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac,
u32 frac, u32 out_div)
{
u64 t;
u32 ret;
t = ath79_ref_clk.rate;
t *= nint;
do_div(t, ref_div);
ret = t;
t = ath79_ref_clk.rate;
t *= nfrac;
do_div(t, ref_div * frac);
ret += t;
ret /= (1 << out_div);
return ret;
}
static void __init ar934x_clocks_init(void)
{
u32 pll, out_div, ref_div, nint, nfrac, frac, clk_ctrl, postdiv;
u32 cpu_pll, ddr_pll;
u32 bootstrap;
void __iomem *dpll_base;
dpll_base = ioremap(AR934X_SRIF_BASE, AR934X_SRIF_SIZE);
bootstrap = ath79_reset_rr(AR934X_RESET_REG_BOOTSTRAP);
if (bootstrap & AR934X_BOOTSTRAP_REF_CLK_40)
ath79_ref_clk.rate = 40 * 1000 * 1000;
else
ath79_ref_clk.rate = 25 * 1000 * 1000;
pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG);
if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
AR934X_SRIF_DPLL2_OUTDIV_MASK;
pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL1_REG);
nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
AR934X_SRIF_DPLL1_NINT_MASK;
nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
AR934X_SRIF_DPLL1_REFDIV_MASK;
frac = 1 << 18;
} else {
pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG);
out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
AR934X_PLL_CPU_CONFIG_NINT_MASK;
nfrac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
frac = 1 << 6;
}
cpu_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
nfrac, frac, out_div);
pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL2_REG);
if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
AR934X_SRIF_DPLL2_OUTDIV_MASK;
pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL1_REG);
nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
AR934X_SRIF_DPLL1_NINT_MASK;
nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
AR934X_SRIF_DPLL1_REFDIV_MASK;
frac = 1 << 18;
} else {
pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG);
out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
AR934X_PLL_DDR_CONFIG_NINT_MASK;
nfrac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
frac = 1 << 10;
}
ddr_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
nfrac, frac, out_div);
clk_ctrl = ath79_pll_rr(AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_SHIFT) &
AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_MASK;
if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_PLL_BYPASS)
ath79_cpu_clk.rate = ath79_ref_clk.rate;
else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPUCLK_FROM_CPUPLL)
ath79_cpu_clk.rate = cpu_pll / (postdiv + 1);
else
ath79_cpu_clk.rate = ddr_pll / (postdiv + 1);
postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_SHIFT) &
AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_MASK;
if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_PLL_BYPASS)
ath79_ddr_clk.rate = ath79_ref_clk.rate;
else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDRCLK_FROM_DDRPLL)
ath79_ddr_clk.rate = ddr_pll / (postdiv + 1);
else
ath79_ddr_clk.rate = cpu_pll / (postdiv + 1);
postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_SHIFT) &
AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_MASK;
if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_PLL_BYPASS)
ath79_ahb_clk.rate = ath79_ref_clk.rate;
else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHBCLK_FROM_DDRPLL)
ath79_ahb_clk.rate = ddr_pll / (postdiv + 1);
else
ath79_ahb_clk.rate = cpu_pll / (postdiv + 1);
ath79_wdt_clk.rate = ath79_ref_clk.rate;
ath79_uart_clk.rate = ath79_ref_clk.rate;
iounmap(dpll_base);
}
void __init ath79_clocks_init(void)
{
if (soc_is_ar71xx())
ar71xx_clocks_init();
else if (soc_is_ar724x())
ar724x_clocks_init();
else if (soc_is_ar913x())
ar913x_clocks_init();
else if (soc_is_ar933x())
ar933x_clocks_init();
else if (soc_is_ar934x())
ar934x_clocks_init();
else
BUG();
pr_info("Clocks: CPU:%lu.%03luMHz, DDR:%lu.%03luMHz, AHB:%lu.%03luMHz, "
"Ref:%lu.%03luMHz",
ath79_cpu_clk.rate / 1000000,
(ath79_cpu_clk.rate / 1000) % 1000,
ath79_ddr_clk.rate / 1000000,
(ath79_ddr_clk.rate / 1000) % 1000,
ath79_ahb_clk.rate / 1000000,
(ath79_ahb_clk.rate / 1000) % 1000,
ath79_ref_clk.rate / 1000000,
(ath79_ref_clk.rate / 1000) % 1000);
}
/*
* Linux clock API
*/
struct clk *clk_get(struct device *dev, const char *id)
{
if (!strcmp(id, "ref"))
return &ath79_ref_clk;
if (!strcmp(id, "cpu"))
return &ath79_cpu_clk;
if (!strcmp(id, "ddr"))
return &ath79_ddr_clk;
if (!strcmp(id, "ahb"))
return &ath79_ahb_clk;
if (!strcmp(id, "wdt"))
return &ath79_wdt_clk;
if (!strcmp(id, "uart"))
return &ath79_uart_clk;
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);