1 /*
2 * ARTPEC-6 clock initialization
3 *
4 * Copyright 2015-2016 Axis Comunications AB.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/clk-provider.h>
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <dt-bindings/clock/axis,artpec6-clkctrl.h>
19
20 #define NUM_I2S_CLOCKS 2
21
22 struct artpec6_clkctrl_drvdata {
23 struct clk *clk_table[ARTPEC6_CLK_NUMCLOCKS];
24 void __iomem *syscon_base;
25 struct clk_onecell_data clk_data;
26 spinlock_t i2scfg_lock;
27 };
28
29 static struct artpec6_clkctrl_drvdata *clkdata;
30
31 static const char *const i2s_clk_names[NUM_I2S_CLOCKS] = {
32 "i2s0",
33 "i2s1",
34 };
35
36 static const int i2s_clk_indexes[NUM_I2S_CLOCKS] = {
37 ARTPEC6_CLK_I2S0_CLK,
38 ARTPEC6_CLK_I2S1_CLK,
39 };
40
of_artpec6_clkctrl_setup(struct device_node * np)41 static void of_artpec6_clkctrl_setup(struct device_node *np)
42 {
43 int i;
44 const char *sys_refclk_name;
45 u32 pll_mode, pll_m, pll_n;
46 struct clk **clks;
47
48 /* Mandatory parent clock. */
49 i = of_property_match_string(np, "clock-names", "sys_refclk");
50 if (i < 0)
51 return;
52
53 sys_refclk_name = of_clk_get_parent_name(np, i);
54
55 clkdata = kzalloc(sizeof(*clkdata), GFP_KERNEL);
56 if (!clkdata)
57 return;
58
59 clks = clkdata->clk_table;
60
61 for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i)
62 clks[i] = ERR_PTR(-EPROBE_DEFER);
63
64 clkdata->syscon_base = of_iomap(np, 0);
65 BUG_ON(clkdata->syscon_base == NULL);
66
67 /* Read PLL1 factors configured by boot strap pins. */
68 pll_mode = (readl(clkdata->syscon_base) >> 6) & 3;
69 switch (pll_mode) {
70 case 0: /* DDR3-2133 mode */
71 pll_m = 4;
72 pll_n = 85;
73 break;
74 case 1: /* DDR3-1866 mode */
75 pll_m = 6;
76 pll_n = 112;
77 break;
78 case 2: /* DDR3-1600 mode */
79 pll_m = 4;
80 pll_n = 64;
81 break;
82 case 3: /* DDR3-1333 mode */
83 pll_m = 8;
84 pll_n = 106;
85 break;
86 }
87
88 clks[ARTPEC6_CLK_CPU] =
89 clk_register_fixed_factor(NULL, "cpu", sys_refclk_name, 0, pll_n,
90 pll_m);
91 clks[ARTPEC6_CLK_CPU_PERIPH] =
92 clk_register_fixed_factor(NULL, "cpu_periph", "cpu", 0, 1, 2);
93
94 /* EPROBE_DEFER on the apb_clock is not handled in amba devices. */
95 clks[ARTPEC6_CLK_UART_PCLK] =
96 clk_register_fixed_factor(NULL, "uart_pclk", "cpu", 0, 1, 8);
97 clks[ARTPEC6_CLK_UART_REFCLK] =
98 clk_register_fixed_rate(NULL, "uart_ref", sys_refclk_name, 0,
99 50000000);
100
101 clks[ARTPEC6_CLK_SPI_PCLK] =
102 clk_register_fixed_factor(NULL, "spi_pclk", "cpu", 0, 1, 8);
103 clks[ARTPEC6_CLK_SPI_SSPCLK] =
104 clk_register_fixed_rate(NULL, "spi_sspclk", sys_refclk_name, 0,
105 50000000);
106
107 clks[ARTPEC6_CLK_DBG_PCLK] =
108 clk_register_fixed_factor(NULL, "dbg_pclk", "cpu", 0, 1, 8);
109
110 clkdata->clk_data.clks = clkdata->clk_table;
111 clkdata->clk_data.clk_num = ARTPEC6_CLK_NUMCLOCKS;
112
113 of_clk_add_provider(np, of_clk_src_onecell_get, &clkdata->clk_data);
114 }
115
116 CLK_OF_DECLARE_DRIVER(artpec6_clkctrl, "axis,artpec6-clkctrl",
117 of_artpec6_clkctrl_setup);
118
artpec6_clkctrl_probe(struct platform_device * pdev)119 static int artpec6_clkctrl_probe(struct platform_device *pdev)
120 {
121 int propidx;
122 struct device_node *np = pdev->dev.of_node;
123 struct device *dev = &pdev->dev;
124 struct clk **clks = clkdata->clk_table;
125 const char *sys_refclk_name;
126 const char *i2s_refclk_name = NULL;
127 const char *frac_clk_name[2] = { NULL, NULL };
128 const char *i2s_mux_parents[2];
129 u32 muxreg;
130 int i;
131 int err = 0;
132
133 /* Mandatory parent clock. */
134 propidx = of_property_match_string(np, "clock-names", "sys_refclk");
135 if (propidx < 0)
136 return -EINVAL;
137
138 sys_refclk_name = of_clk_get_parent_name(np, propidx);
139
140 /* Find clock names of optional parent clocks. */
141 propidx = of_property_match_string(np, "clock-names", "i2s_refclk");
142 if (propidx >= 0)
143 i2s_refclk_name = of_clk_get_parent_name(np, propidx);
144
145 propidx = of_property_match_string(np, "clock-names", "frac_clk0");
146 if (propidx >= 0)
147 frac_clk_name[0] = of_clk_get_parent_name(np, propidx);
148 propidx = of_property_match_string(np, "clock-names", "frac_clk1");
149 if (propidx >= 0)
150 frac_clk_name[1] = of_clk_get_parent_name(np, propidx);
151
152 spin_lock_init(&clkdata->i2scfg_lock);
153
154 clks[ARTPEC6_CLK_NAND_CLKA] =
155 clk_register_fixed_factor(dev, "nand_clka", "cpu", 0, 1, 8);
156 clks[ARTPEC6_CLK_NAND_CLKB] =
157 clk_register_fixed_rate(dev, "nand_clkb", sys_refclk_name, 0,
158 100000000);
159 clks[ARTPEC6_CLK_ETH_ACLK] =
160 clk_register_fixed_factor(dev, "eth_aclk", "cpu", 0, 1, 4);
161 clks[ARTPEC6_CLK_DMA_ACLK] =
162 clk_register_fixed_factor(dev, "dma_aclk", "cpu", 0, 1, 4);
163 clks[ARTPEC6_CLK_PTP_REF] =
164 clk_register_fixed_rate(dev, "ptp_ref", sys_refclk_name, 0,
165 100000000);
166 clks[ARTPEC6_CLK_SD_PCLK] =
167 clk_register_fixed_rate(dev, "sd_pclk", sys_refclk_name, 0,
168 100000000);
169 clks[ARTPEC6_CLK_SD_IMCLK] =
170 clk_register_fixed_rate(dev, "sd_imclk", sys_refclk_name, 0,
171 100000000);
172 clks[ARTPEC6_CLK_I2S_HST] =
173 clk_register_fixed_factor(dev, "i2s_hst", "cpu", 0, 1, 8);
174
175 for (i = 0; i < NUM_I2S_CLOCKS; ++i) {
176 if (i2s_refclk_name && frac_clk_name[i]) {
177 i2s_mux_parents[0] = frac_clk_name[i];
178 i2s_mux_parents[1] = i2s_refclk_name;
179
180 clks[i2s_clk_indexes[i]] =
181 clk_register_mux(dev, i2s_clk_names[i],
182 i2s_mux_parents, 2,
183 CLK_SET_RATE_NO_REPARENT |
184 CLK_SET_RATE_PARENT,
185 clkdata->syscon_base + 0x14, i, 1,
186 0, &clkdata->i2scfg_lock);
187 } else if (frac_clk_name[i]) {
188 /* Lock the mux for internal clock reference. */
189 muxreg = readl(clkdata->syscon_base + 0x14);
190 muxreg &= ~BIT(i);
191 writel(muxreg, clkdata->syscon_base + 0x14);
192 clks[i2s_clk_indexes[i]] =
193 clk_register_fixed_factor(dev, i2s_clk_names[i],
194 frac_clk_name[i], 0, 1,
195 1);
196 } else if (i2s_refclk_name) {
197 /* Lock the mux for external clock reference. */
198 muxreg = readl(clkdata->syscon_base + 0x14);
199 muxreg |= BIT(i);
200 writel(muxreg, clkdata->syscon_base + 0x14);
201 clks[i2s_clk_indexes[i]] =
202 clk_register_fixed_factor(dev, i2s_clk_names[i],
203 i2s_refclk_name, 0, 1, 1);
204 }
205 }
206
207 clks[ARTPEC6_CLK_I2C] =
208 clk_register_fixed_rate(dev, "i2c", sys_refclk_name, 0, 100000000);
209
210 clks[ARTPEC6_CLK_SYS_TIMER] =
211 clk_register_fixed_rate(dev, "timer", sys_refclk_name, 0,
212 100000000);
213 clks[ARTPEC6_CLK_FRACDIV_IN] =
214 clk_register_fixed_rate(dev, "fracdiv_in", sys_refclk_name, 0,
215 600000000);
216
217 for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) {
218 if (IS_ERR(clks[i]) && PTR_ERR(clks[i]) != -EPROBE_DEFER) {
219 dev_err(dev,
220 "Failed to register clock at index %d err=%ld\n",
221 i, PTR_ERR(clks[i]));
222 err = PTR_ERR(clks[i]);
223 }
224 }
225
226 return err;
227 }
228
229 static const struct of_device_id artpec_clkctrl_of_match[] = {
230 { .compatible = "axis,artpec6-clkctrl" },
231 {}
232 };
233
234 static struct platform_driver artpec6_clkctrl_driver = {
235 .probe = artpec6_clkctrl_probe,
236 .driver = {
237 .name = "artpec6_clkctrl",
238 .of_match_table = artpec_clkctrl_of_match,
239 },
240 };
241
242 builtin_platform_driver(artpec6_clkctrl_driver);
243