ramips: fix cpu clock of mt7621 and add dt clk devices

For a long time the mt7621 uses a fixed cpu clock which causes a problem
if the cpu frequency is not 880MHz.

This patch fixes the cpu clock calculation and adds the cpu/bus clkdev
which will be used in dts.

Signed-off-by: Weijie Gao <hackpascal@gmail.com>
This commit is contained in:
Weijie Gao 2018-11-19 01:14:53 +08:00 committed by John Crispin
parent f5af8be636
commit c7ca224299
3 changed files with 232 additions and 19 deletions

View file

@ -1,4 +1,5 @@
#include <dt-bindings/interrupt-controller/mips-gic.h>
#include <dt-bindings/clock/mt7621-clk.h>
/ {
#address-cells = <1>;
@ -33,6 +34,13 @@
serial0 = &uartlite;
};
pll: pll {
compatible = "mediatek,mt7621-pll", "syscon";
#clock-cells = <1>;
clock-output-names = "cpu", "bus";
};
cpuclock: cpuclock {
#clock-cells = <0>;
compatible = "fixed-clock";

View file

@ -85,22 +85,3 @@
endchoice
choice
--- a/arch/mips/ralink/timer-gic.c
+++ b/arch/mips/ralink/timer-gic.c
@@ -12,6 +12,7 @@
#include <linux/of.h>
#include <linux/clk-provider.h>
#include <linux/clocksource.h>
+#include <asm/time.h>
#include "common.h"
@@ -19,6 +20,8 @@ void __init plat_time_init(void)
{
ralink_of_remap();
+ mips_hpt_frequency = 880000000 / 2;
+
of_clk_init(NULL);
timer_probe();
}

View file

@ -0,0 +1,224 @@
--- a/arch/mips/include/asm/mach-ralink/mt7621.h
+++ b/arch/mips/include/asm/mach-ralink/mt7621.h
@@ -19,6 +19,10 @@
#define SYSC_REG_CHIP_REV 0x0c
#define SYSC_REG_SYSTEM_CONFIG0 0x10
#define SYSC_REG_SYSTEM_CONFIG1 0x14
+#define SYSC_REG_CLKCFG0 0x2c
+#define SYSC_REG_CUR_CLK_STS 0x44
+
+#define MEMC_REG_CPU_PLL 0x648
#define CHIP_REV_PKG_MASK 0x1
#define CHIP_REV_PKG_SHIFT 16
@@ -26,6 +30,22 @@
#define CHIP_REV_VER_SHIFT 8
#define CHIP_REV_ECO_MASK 0xf
+#define XTAL_MODE_SEL_MASK 0x7
+#define XTAL_MODE_SEL_SHIFT 6
+
+#define CPU_CLK_SEL_MASK 0x3
+#define CPU_CLK_SEL_SHIFT 30
+
+#define CUR_CPU_FDIV_MASK 0x1f
+#define CUR_CPU_FDIV_SHIFT 8
+#define CUR_CPU_FFRAC_MASK 0x1f
+#define CUR_CPU_FFRAC_SHIFT 0
+
+#define CPU_PLL_PREDIV_MASK 0x3
+#define CPU_PLL_PREDIV_SHIFT 12
+#define CPU_PLL_FBDIV_MASK 0x7f
+#define CPU_PLL_FBDIV_SHIFT 4
+
#define MT7621_DRAM_BASE 0x0
#define MT7621_DDR2_SIZE_MIN 32
#define MT7621_DDR2_SIZE_MAX 256
--- a/arch/mips/ralink/mt7621.c
+++ b/arch/mips/ralink/mt7621.c
@@ -10,6 +10,10 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/jiffies.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <dt-bindings/clock/mt7621-clk.h>
#include <asm/mipsregs.h>
#include <asm/smp-ops.h>
@@ -18,16 +22,12 @@
#include <asm/mach-ralink/mt7621.h>
#include <asm/mips-boards/launch.h>
#include <asm/delay.h>
+#include <asm/time.h>
#include <pinmux.h>
#include "common.h"
-#define SYSC_REG_SYSCFG 0x10
-#define SYSC_REG_CPLL_CLKCFG0 0x2c
-#define SYSC_REG_CUR_CLK_STS 0x44
-#define CPU_CLK_SEL (BIT(30) | BIT(31))
-
#define MT7621_GPIO_MODE_UART1 1
#define MT7621_GPIO_MODE_I2C 2
#define MT7621_GPIO_MODE_UART3_MASK 0x3
@@ -113,49 +113,89 @@ static struct rt2880_pmx_group mt7621_pi
{ 0 }
};
+static struct clk *clks[MT7621_CLK_MAX];
+static struct clk_onecell_data clk_data = {
+ .clks = clks,
+ .clk_num = ARRAY_SIZE(clks),
+};
+
phys_addr_t mips_cpc_default_phys_base(void)
{
panic("Cannot detect cpc address");
}
-void __init ralink_clk_init(void)
+static struct clk *__init mt7621_add_sys_clkdev(
+ const char *id, unsigned long rate)
{
- int cpu_fdiv = 0;
- int cpu_ffrac = 0;
- int fbdiv = 0;
- u32 clk_sts, syscfg;
- u8 clk_sel = 0, xtal_mode;
- u32 cpu_clk;
+ struct clk *clk;
+ int err;
+
+ clk = clk_register_fixed_rate(NULL, id, NULL, 0, rate);
+ if (IS_ERR(clk))
+ panic("failed to allocate %s clock structure", id);
+
+ err = clk_register_clkdev(clk, id, NULL);
+ if (err)
+ panic("unable to register %s clock device", id);
- if ((rt_sysc_r32(SYSC_REG_CPLL_CLKCFG0) & CPU_CLK_SEL) != 0)
- clk_sel = 1;
+ return clk;
+}
+
+void __init ralink_clk_init(void)
+{
+ u32 syscfg, xtal_sel, clkcfg, clk_sel, curclk, ffiv, ffrac;
+ u32 pll, prediv, fbdiv;
+ u32 xtal_clk, cpu_clk, bus_clk;
+ const static u32 prediv_tbl[] = {0, 1, 2, 2};
+
+ syscfg = rt_sysc_r32(SYSC_REG_SYSTEM_CONFIG0);
+ xtal_sel = (syscfg >> XTAL_MODE_SEL_SHIFT) & XTAL_MODE_SEL_MASK;
+
+ clkcfg = rt_sysc_r32(SYSC_REG_CLKCFG0);
+ clk_sel = (clkcfg >> CPU_CLK_SEL_SHIFT) & CPU_CLK_SEL_MASK;
+
+ curclk = rt_sysc_r32(SYSC_REG_CUR_CLK_STS);
+ ffiv = (curclk >> CUR_CPU_FDIV_SHIFT) & CUR_CPU_FDIV_MASK;
+ ffrac = (curclk >> CUR_CPU_FFRAC_SHIFT) & CUR_CPU_FFRAC_MASK;
+
+ if (xtal_sel <= 2)
+ xtal_clk = 20 * 1000 * 1000;
+ else if (xtal_sel <= 5)
+ xtal_clk = 40 * 1000 * 1000;
+ else
+ xtal_clk = 25 * 1000 * 1000;
switch (clk_sel) {
case 0:
- clk_sts = rt_sysc_r32(SYSC_REG_CUR_CLK_STS);
- cpu_fdiv = ((clk_sts >> 8) & 0x1F);
- cpu_ffrac = (clk_sts & 0x1F);
- cpu_clk = (500 * cpu_ffrac / cpu_fdiv) * 1000 * 1000;
+ cpu_clk = 500 * 1000 * 1000;
break;
-
case 1:
- fbdiv = ((rt_sysc_r32(0x648) >> 4) & 0x7F) + 1;
- syscfg = rt_sysc_r32(SYSC_REG_SYSCFG);
- xtal_mode = (syscfg >> 6) & 0x7;
- if (xtal_mode >= 6) {
- /* 25Mhz Xtal */
- cpu_clk = 25 * fbdiv * 1000 * 1000;
- } else if (xtal_mode >= 3) {
- /* 40Mhz Xtal */
- cpu_clk = 40 * fbdiv * 1000 * 1000;
- } else {
- /* 20Mhz Xtal */
- cpu_clk = 20 * fbdiv * 1000 * 1000;
- }
+ pll = rt_memc_r32(MEMC_REG_CPU_PLL);
+ fbdiv = (pll >> CPU_PLL_FBDIV_SHIFT) & CPU_PLL_FBDIV_MASK;
+ prediv = (pll >> CPU_PLL_PREDIV_SHIFT) & CPU_PLL_PREDIV_MASK;
+ cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
break;
+ default:
+ cpu_clk = xtal_clk;
}
+
+ cpu_clk = cpu_clk / ffiv * ffrac;
+ bus_clk = cpu_clk / 4;
+
+ clks[MT7621_CLK_CPU] = mt7621_add_sys_clkdev("cpu", cpu_clk);
+ clks[MT7621_CLK_BUS] = mt7621_add_sys_clkdev("bus", bus_clk);
+
+ pr_info("CPU Clock: %dMHz\n", cpu_clk / 1000000);
+ mips_hpt_frequency = cpu_clk / 2;
}
+static void __init mt7621_clocks_init_dt(struct device_node *np)
+{
+ of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+}
+
+CLK_OF_DECLARE(ar7100, "mediatek,mt7621-pll", mt7621_clocks_init_dt);
+
void __init ralink_of_remap(void)
{
rt_sysc_membase = plat_of_remap_node("mtk,mt7621-sysc");
--- a/arch/mips/ralink/timer-gic.c
+++ b/arch/mips/ralink/timer-gic.c
@@ -11,14 +11,14 @@
#include <linux/of.h>
#include <linux/clk-provider.h>
-#include <linux/clocksource.h>
+#include <asm/time.h>
#include "common.h"
void __init plat_time_init(void)
{
ralink_of_remap();
-
+ ralink_clk_init();
of_clk_init(NULL);
timer_probe();
}
--- a/include/dt-bindings/clock/mt7621-clk.h
+++ b/include/dt-bindings/clock/mt7621-clk.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2018 Weijie Gao <hackpascal@gmail.com>
+ *
+ * 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.
+ *
+ */
+
+#ifndef __DT_BINDINGS_MT7621_CLK_H
+#define __DT_BINDINGS_MT7621_CLK_H
+
+#define MT7621_CLK_CPU 0
+#define MT7621_CLK_BUS 1
+
+#define MT7621_CLK_MAX 2
+
+#endif /* __DT_BINDINGS_MT7621_CLK_H */