tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2019 Christoph Hellwig.
4 * Copyright (c) 2019 Western Digital Corporation or its affiliates.
5 */
6#include <linux/types.h>
7#include <linux/io.h>
8#include <linux/of.h>
9#include <linux/platform_device.h>
10#include <linux/clk-provider.h>
11#include <linux/clkdev.h>
12#include <linux/bitfield.h>
13#include <asm/soc.h>
14
15#define K210_SYSCTL_CLK0_FREQ 26000000UL
16
17/* Registers base address */
18#define K210_SYSCTL_SYSCTL_BASE_ADDR 0x50440000ULL
19
20/* Registers */
21#define K210_SYSCTL_PLL0 0x08
22#define K210_SYSCTL_PLL1 0x0c
23/* clkr: 4bits, clkf1: 6bits, clkod: 4bits, bwadj: 4bits */
24#define PLL_RESET (1 << 20)
25#define PLL_PWR (1 << 21)
26#define PLL_INTFB (1 << 22)
27#define PLL_BYPASS (1 << 23)
28#define PLL_TEST (1 << 24)
29#define PLL_OUT_EN (1 << 25)
30#define PLL_TEST_EN (1 << 26)
31#define K210_SYSCTL_PLL_LOCK 0x18
32#define PLL0_LOCK1 (1 << 0)
33#define PLL0_LOCK2 (1 << 1)
34#define PLL0_SLIP_CLEAR (1 << 2)
35#define PLL0_TEST_CLK_OUT (1 << 3)
36#define PLL1_LOCK1 (1 << 8)
37#define PLL1_LOCK2 (1 << 9)
38#define PLL1_SLIP_CLEAR (1 << 10)
39#define PLL1_TEST_CLK_OUT (1 << 11)
40#define PLL2_LOCK1 (1 << 16)
41#define PLL2_LOCK2 (1 << 16)
42#define PLL2_SLIP_CLEAR (1 << 18)
43#define PLL2_TEST_CLK_OUT (1 << 19)
44#define K210_SYSCTL_CLKSEL0 0x20
45#define CLKSEL_ACLK (1 << 0)
46#define K210_SYSCTL_CLKEN_CENT 0x28
47#define CLKEN_CPU (1 << 0)
48#define CLKEN_SRAM0 (1 << 1)
49#define CLKEN_SRAM1 (1 << 2)
50#define CLKEN_APB0 (1 << 3)
51#define CLKEN_APB1 (1 << 4)
52#define CLKEN_APB2 (1 << 5)
53#define K210_SYSCTL_CLKEN_PERI 0x2c
54#define CLKEN_ROM (1 << 0)
55#define CLKEN_DMA (1 << 1)
56#define CLKEN_AI (1 << 2)
57#define CLKEN_DVP (1 << 3)
58#define CLKEN_FFT (1 << 4)
59#define CLKEN_GPIO (1 << 5)
60#define CLKEN_SPI0 (1 << 6)
61#define CLKEN_SPI1 (1 << 7)
62#define CLKEN_SPI2 (1 << 8)
63#define CLKEN_SPI3 (1 << 9)
64#define CLKEN_I2S0 (1 << 10)
65#define CLKEN_I2S1 (1 << 11)
66#define CLKEN_I2S2 (1 << 12)
67#define CLKEN_I2C0 (1 << 13)
68#define CLKEN_I2C1 (1 << 14)
69#define CLKEN_I2C2 (1 << 15)
70#define CLKEN_UART1 (1 << 16)
71#define CLKEN_UART2 (1 << 17)
72#define CLKEN_UART3 (1 << 18)
73#define CLKEN_AES (1 << 19)
74#define CLKEN_FPIO (1 << 20)
75#define CLKEN_TIMER0 (1 << 21)
76#define CLKEN_TIMER1 (1 << 22)
77#define CLKEN_TIMER2 (1 << 23)
78#define CLKEN_WDT0 (1 << 24)
79#define CLKEN_WDT1 (1 << 25)
80#define CLKEN_SHA (1 << 26)
81#define CLKEN_OTP (1 << 27)
82#define CLKEN_RTC (1 << 29)
83
84struct k210_sysctl {
85 void __iomem *regs;
86 struct clk_hw hw;
87};
88
89static void k210_set_bits(u32 val, void __iomem *reg)
90{
91 writel(readl(reg) | val, reg);
92}
93
94static void k210_clear_bits(u32 val, void __iomem *reg)
95{
96 writel(readl(reg) & ~val, reg);
97}
98
99static void k210_pll1_enable(void __iomem *regs)
100{
101 u32 val;
102
103 val = readl(regs + K210_SYSCTL_PLL1);
104 val &= ~GENMASK(19, 0); /* clkr1 = 0 */
105 val |= FIELD_PREP(GENMASK(9, 4), 0x3B); /* clkf1 = 59 */
106 val |= FIELD_PREP(GENMASK(13, 10), 0x3); /* clkod1 = 3 */
107 val |= FIELD_PREP(GENMASK(19, 14), 0x3B); /* bwadj1 = 59 */
108 writel(val, regs + K210_SYSCTL_PLL1);
109
110 k210_clear_bits(PLL_BYPASS, regs + K210_SYSCTL_PLL1);
111 k210_set_bits(PLL_PWR, regs + K210_SYSCTL_PLL1);
112
113 /*
114 * Reset the pll. The magic NOPs come from the Kendryte reference SDK.
115 */
116 k210_clear_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
117 k210_set_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
118 nop();
119 nop();
120 k210_clear_bits(PLL_RESET, regs + K210_SYSCTL_PLL1);
121
122 for (;;) {
123 val = readl(regs + K210_SYSCTL_PLL_LOCK);
124 if (val & PLL1_LOCK2)
125 break;
126 writel(val | PLL1_SLIP_CLEAR, regs + K210_SYSCTL_PLL_LOCK);
127 }
128
129 k210_set_bits(PLL_OUT_EN, regs + K210_SYSCTL_PLL1);
130}
131
132static unsigned long k210_sysctl_clk_recalc_rate(struct clk_hw *hw,
133 unsigned long parent_rate)
134{
135 struct k210_sysctl *s = container_of(hw, struct k210_sysctl, hw);
136 u32 clksel0, pll0;
137 u64 pll0_freq, clkr0, clkf0, clkod0;
138
139 /*
140 * If the clock selector is not set, use the base frequency.
141 * Otherwise, use PLL0 frequency with a frequency divisor.
142 */
143 clksel0 = readl(s->regs + K210_SYSCTL_CLKSEL0);
144 if (!(clksel0 & CLKSEL_ACLK))
145 return K210_SYSCTL_CLK0_FREQ;
146
147 /*
148 * Get PLL0 frequency:
149 * freq = base frequency * clkf0 / (clkr0 * clkod0)
150 */
151 pll0 = readl(s->regs + K210_SYSCTL_PLL0);
152 clkr0 = 1 + FIELD_GET(GENMASK(3, 0), pll0);
153 clkf0 = 1 + FIELD_GET(GENMASK(9, 4), pll0);
154 clkod0 = 1 + FIELD_GET(GENMASK(13, 10), pll0);
155 pll0_freq = clkf0 * K210_SYSCTL_CLK0_FREQ / (clkr0 * clkod0);
156
157 /* Get the frequency divisor from the clock selector */
158 return pll0_freq / (2ULL << FIELD_GET(0x00000006, clksel0));
159}
160
161static const struct clk_ops k210_sysctl_clk_ops = {
162 .recalc_rate = k210_sysctl_clk_recalc_rate,
163};
164
165static const struct clk_init_data k210_clk_init_data = {
166 .name = "k210-sysctl-pll1",
167 .ops = &k210_sysctl_clk_ops,
168};
169
170static int k210_sysctl_probe(struct platform_device *pdev)
171{
172 struct k210_sysctl *s;
173 int error;
174
175 pr_info("Kendryte K210 SoC sysctl\n");
176
177 s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
178 if (!s)
179 return -ENOMEM;
180
181 s->regs = devm_ioremap_resource(&pdev->dev,
182 platform_get_resource(pdev, IORESOURCE_MEM, 0));
183 if (IS_ERR(s->regs))
184 return PTR_ERR(s->regs);
185
186 s->hw.init = &k210_clk_init_data;
187 error = devm_clk_hw_register(&pdev->dev, &s->hw);
188 if (error) {
189 dev_err(&pdev->dev, "failed to register clk");
190 return error;
191 }
192
193 error = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
194 &s->hw);
195 if (error) {
196 dev_err(&pdev->dev, "adding clk provider failed\n");
197 return error;
198 }
199
200 return 0;
201}
202
203static const struct of_device_id k210_sysctl_of_match[] = {
204 { .compatible = "kendryte,k210-sysctl", },
205 {}
206};
207
208static struct platform_driver k210_sysctl_driver = {
209 .driver = {
210 .name = "k210-sysctl",
211 .of_match_table = k210_sysctl_of_match,
212 },
213 .probe = k210_sysctl_probe,
214};
215
216static int __init k210_sysctl_init(void)
217{
218 return platform_driver_register(&k210_sysctl_driver);
219}
220core_initcall(k210_sysctl_init);
221
222/*
223 * This needs to be called very early during initialization, given that
224 * PLL1 needs to be enabled to be able to use all SRAM.
225 */
226static void __init k210_soc_early_init(const void *fdt)
227{
228 void __iomem *regs;
229
230 regs = ioremap(K210_SYSCTL_SYSCTL_BASE_ADDR, 0x1000);
231 if (!regs)
232 panic("K210 sysctl ioremap");
233
234 /* Enable PLL1 to make the KPU SRAM useable */
235 k210_pll1_enable(regs);
236
237 k210_set_bits(PLL_OUT_EN, regs + K210_SYSCTL_PLL0);
238
239 k210_set_bits(CLKEN_CPU | CLKEN_SRAM0 | CLKEN_SRAM1,
240 regs + K210_SYSCTL_CLKEN_CENT);
241 k210_set_bits(CLKEN_ROM | CLKEN_TIMER0 | CLKEN_RTC,
242 regs + K210_SYSCTL_CLKEN_PERI);
243
244 k210_set_bits(CLKSEL_ACLK, regs + K210_SYSCTL_CLKSEL0);
245
246 iounmap(regs);
247}
248SOC_EARLY_INIT_DECLARE(generic_k210, "kendryte,k210", k210_soc_early_init);