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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2019 Christoph Hellwig.
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*/
#include <linux/types.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/bitfield.h>
#include <asm/soc.h>
#include <soc/canaan/k210-sysctl.h>
#define K210_SYSCTL_CLK0_FREQ 26000000UL
/* Registers base address */
#define K210_SYSCTL_SYSCTL_BASE_ADDR 0x50440000ULL
/* Register bits */
/* K210_SYSCTL_PLL1: clkr: 4bits, clkf1: 6bits, clkod: 4bits, bwadj: 4bits */
#define PLL_RESET (1 << 20)
#define PLL_PWR (1 << 21)
#define PLL_BYPASS (1 << 23)
#define PLL_OUT_EN (1 << 25)
/* K210_SYSCTL_PLL_LOCK */
#define PLL1_LOCK1 (1 << 8)
#define PLL1_LOCK2 (1 << 9)
#define PLL1_SLIP_CLEAR (1 << 10)
/* K210_SYSCTL_SEL0 */
#define CLKSEL_ACLK (1 << 0)
/* K210_SYSCTL_CLKEN_CENT */
#define CLKEN_CPU (1 << 0)
#define CLKEN_SRAM0 (1 << 1)
#define CLKEN_SRAM1 (1 << 2)
/* K210_SYSCTL_EN_PERI */
#define CLKEN_ROM (1 << 0)
#define CLKEN_TIMER0 (1 << 21)
#define CLKEN_RTC (1 << 29)
struct k210_sysctl {
void __iomem *regs;
struct clk_hw hw;
};
static void k210_set_bits(u32 val, void __iomem *reg)
{
writel(readl(reg) | val, reg);
}
static void k210_clear_bits(u32 val, void __iomem *reg)
{
writel(readl(reg) & ~val, reg);
}
static void k210_pll1_enable(void __iomem *regs)
{
u32 val;
val = readl(regs + K210_SYSCTL_PLL1);
val &= ~GENMASK(19, 0); /* clkr1 = 0 */
val |= FIELD_PREP(GENMASK(9, 4), 0x3B); /* clkf1 = 59 */
val |= FIELD_PREP(GENMASK(13, 10), 0x3); /* clkod1 = 3 */
val |= FIELD_PREP(GENMASK(19, 14), 0x3B); /* bwadj1 = 59 */
writel(val, regs + K210_SYSCTL_PLL1);
k210_clear_bits(PLL_BYPASS, regs + K210_SYSCTL_PLL1);
k210_set_bits(PLL_PWR, regs + K210_SYSCTL_PLL1);
/*
* Reset the pll. The magic NOPs come from the Kendryte reference SDK.
*/
k210_clear_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
k210_set_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
nop();
nop();
k210_clear_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
for (;;) {
val = readl(regs + K210_SYSCTL_PLL_LOCK);
if (val & PLL1_LOCK2)
break;
writel(val | PLL1_SLIP_CLEAR, regs + K210_SYSCTL_PLL_LOCK);
}
k210_set_bits(PLL_OUT_EN, regs + K210_SYSCTL_PLL1);
}
static unsigned long k210_sysctl_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct k210_sysctl *s = container_of(hw, struct k210_sysctl, hw);
u32 clksel0, pll0;
u64 pll0_freq, clkr0, clkf0, clkod0;
/*
* If the clock selector is not set, use the base frequency.
* Otherwise, use PLL0 frequency with a frequency divisor.
*/
clksel0 = readl(s->regs + K210_SYSCTL_SEL0);
if (!(clksel0 & CLKSEL_ACLK))
return K210_SYSCTL_CLK0_FREQ;
/*
* Get PLL0 frequency:
* freq = base frequency * clkf0 / (clkr0 * clkod0)
*/
pll0 = readl(s->regs + K210_SYSCTL_PLL0);
clkr0 = 1 + FIELD_GET(GENMASK(3, 0), pll0);
clkf0 = 1 + FIELD_GET(GENMASK(9, 4), pll0);
clkod0 = 1 + FIELD_GET(GENMASK(13, 10), pll0);
pll0_freq = clkf0 * K210_SYSCTL_CLK0_FREQ / (clkr0 * clkod0);
/* Get the frequency divisor from the clock selector */
return pll0_freq / (2ULL << FIELD_GET(0x00000006, clksel0));
}
static const struct clk_ops k210_sysctl_clk_ops = {
.recalc_rate = k210_sysctl_clk_recalc_rate,
};
static const struct clk_init_data k210_clk_init_data = {
.name = "k210-sysctl-pll1",
.ops = &k210_sysctl_clk_ops,
};
static int k210_sysctl_probe(struct platform_device *pdev)
{
struct k210_sysctl *s;
int error;
pr_info("Kendryte K210 SoC sysctl\n");
s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
s->regs = devm_ioremap_resource(&pdev->dev,
platform_get_resource(pdev, IORESOURCE_MEM, 0));
if (IS_ERR(s->regs))
return PTR_ERR(s->regs);
s->hw.init = &k210_clk_init_data;
error = devm_clk_hw_register(&pdev->dev, &s->hw);
if (error) {
dev_err(&pdev->dev, "failed to register clk");
return error;
}
error = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
&s->hw);
if (error) {
dev_err(&pdev->dev, "adding clk provider failed\n");
return error;
}
return 0;
}
static const struct of_device_id k210_sysctl_of_match[] = {
{ .compatible = "kendryte,k210-sysctl", },
{}
};
static struct platform_driver k210_sysctl_driver = {
.driver = {
.name = "k210-sysctl",
.of_match_table = k210_sysctl_of_match,
},
.probe = k210_sysctl_probe,
};
static int __init k210_sysctl_init(void)
{
return platform_driver_register(&k210_sysctl_driver);
}
core_initcall(k210_sysctl_init);
/*
* This needs to be called very early during initialization, given that
* PLL1 needs to be enabled to be able to use all SRAM.
*/
static void __init k210_soc_early_init(const void *fdt)
{
void __iomem *regs;
regs = ioremap(K210_SYSCTL_SYSCTL_BASE_ADDR, 0x1000);
if (!regs)
panic("K210 sysctl ioremap");
/* Enable PLL1 to make the KPU SRAM useable */
k210_pll1_enable(regs);
k210_set_bits(PLL_OUT_EN, regs + K210_SYSCTL_PLL0);
k210_set_bits(CLKEN_CPU | CLKEN_SRAM0 | CLKEN_SRAM1,
regs + K210_SYSCTL_EN_CENT);
k210_set_bits(CLKEN_ROM | CLKEN_TIMER0 | CLKEN_RTC,
regs + K210_SYSCTL_EN_PERI);
k210_set_bits(CLKSEL_ACLK, regs + K210_SYSCTL_SEL0);
iounmap(regs);
}
SOC_EARLY_INIT_DECLARE(generic_k210, "kendryte,k210", k210_soc_early_init);
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