u-boot/drivers/clk/mtmips/clk-mt7628.c
Weijie Gao 77ed3c42fe clk: add clock driver for MediaTek MT76x8 platform
This patch adds a clock driver for MediaTek MT7628/7688 SoC.
It provides clock gate control as well as getting clock frequency for
CPU/SYS/XTAL and some peripherals.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
2019-10-25 17:20:44 +02:00

158 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 MediaTek Inc. All Rights Reserved.
*
* Author: Weijie Gao <weijie.gao@mediatek.com>
*/
#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <dt-bindings/clock/mt7628-clk.h>
#include <linux/bitops.h>
#include <linux/io.h>
/* SYSCFG0 */
#define XTAL_40M_SEL BIT(6)
/* CLKCFG0 */
#define CLKCFG0_REG 0x0
#define PERI_CLK_FROM_XTAL_SEL BIT(4)
#define CPU_PLL_FROM_BBP BIT(1)
#define CPU_PLL_FROM_XTAL BIT(0)
/* CLKCFG1 */
#define CLKCFG1_REG 0x4
#define CLK_SRC_CPU -1
#define CLK_SRC_CPU_D2 -2
#define CLK_SRC_SYS -3
#define CLK_SRC_XTAL -4
#define CLK_SRC_PERI -5
struct mt7628_clk_priv {
void __iomem *base;
int cpu_clk;
int sys_clk;
int xtal_clk;
};
static const int mt7628_clks[] = {
[CLK_SYS] = CLK_SRC_SYS,
[CLK_CPU] = CLK_SRC_CPU,
[CLK_XTAL] = CLK_SRC_XTAL,
[CLK_PWM] = CLK_SRC_PERI,
[CLK_MIPS_CNT] = CLK_SRC_CPU_D2,
[CLK_UART2] = CLK_SRC_PERI,
[CLK_UART1] = CLK_SRC_PERI,
[CLK_UART0] = CLK_SRC_PERI,
[CLK_SPI] = CLK_SRC_SYS,
[CLK_I2C] = CLK_SRC_PERI,
};
static ulong mt7628_clk_get_rate(struct clk *clk)
{
struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
u32 val;
if (clk->id >= ARRAY_SIZE(mt7628_clks))
return 0;
switch (mt7628_clks[clk->id]) {
case CLK_SRC_CPU:
return priv->cpu_clk;
case CLK_SRC_CPU_D2:
return priv->cpu_clk / 2;
case CLK_SRC_SYS:
return priv->sys_clk;
case CLK_SRC_XTAL:
return priv->xtal_clk;
case CLK_SRC_PERI:
val = readl(priv->base + CLKCFG0_REG);
if (val & PERI_CLK_FROM_XTAL_SEL)
return priv->xtal_clk;
else
return 40000000;
default:
return mt7628_clks[clk->id];
}
}
static int mt7628_clk_enable(struct clk *clk)
{
struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
if (clk->id > 31)
return -1;
setbits_32(priv->base + CLKCFG1_REG, BIT(clk->id));
return 0;
}
static int mt7628_clk_disable(struct clk *clk)
{
struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
if (clk->id > 31)
return -1;
clrbits_32(priv->base + CLKCFG1_REG, BIT(clk->id));
return 0;
}
const struct clk_ops mt7628_clk_ops = {
.enable = mt7628_clk_enable,
.disable = mt7628_clk_disable,
.get_rate = mt7628_clk_get_rate,
};
static int mt7628_clk_probe(struct udevice *dev)
{
struct mt7628_clk_priv *priv = dev_get_priv(dev);
void __iomem *syscfg_base;
u32 val;
priv->base = (void __iomem *)dev_remap_addr_index(dev, 0);
if (!priv->base)
return -EINVAL;
syscfg_base = (void __iomem *)dev_remap_addr_index(dev, 1);
if (!syscfg_base)
return -EINVAL;
val = readl(syscfg_base);
if (val & XTAL_40M_SEL)
priv->xtal_clk = 40000000;
else
priv->xtal_clk = 25000000;
val = readl(priv->base + CLKCFG0_REG);
if (val & CPU_PLL_FROM_BBP)
priv->cpu_clk = 480000000;
else if (val & CPU_PLL_FROM_XTAL)
priv->cpu_clk = priv->xtal_clk;
else if (priv->xtal_clk == 40000000)
priv->cpu_clk = 580000000; /* (xtal_freq / 2) * 29 */
else
priv->cpu_clk = 575000000; /* xtal_freq * 23 */
priv->sys_clk = priv->cpu_clk / 3;
return 0;
}
static const struct udevice_id mt7628_clk_ids[] = {
{ .compatible = "mediatek,mt7628-clk" },
{ }
};
U_BOOT_DRIVER(mt7628_clk) = {
.name = "mt7628-clk",
.id = UCLASS_CLK,
.of_match = mt7628_clk_ids,
.probe = mt7628_clk_probe,
.priv_auto_alloc_size = sizeof(struct mt7628_clk_priv),
.ops = &mt7628_clk_ops,
};