1 /*
2  * Synopsys AXS10X SDP I2S PLL clock driver
3  *
4  * Copyright (C) 2016 Synopsys
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2. This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 
11 #include <linux/platform_device.h>
12 #include <linux/module.h>
13 #include <linux/clk-provider.h>
14 #include <linux/err.h>
15 #include <linux/device.h>
16 #include <linux/io.h>
17 #include <linux/of_address.h>
18 #include <linux/slab.h>
19 #include <linux/of.h>
20 
21 /* PLL registers addresses */
22 #define PLL_IDIV_REG	0x0
23 #define PLL_FBDIV_REG	0x4
24 #define PLL_ODIV0_REG	0x8
25 #define PLL_ODIV1_REG	0xC
26 
27 struct i2s_pll_cfg {
28 	unsigned int rate;
29 	unsigned int idiv;
30 	unsigned int fbdiv;
31 	unsigned int odiv0;
32 	unsigned int odiv1;
33 };
34 
35 static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
36 	/* 27 Mhz */
37 	{ 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
38 	{ 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
39 	{ 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
40 	{ 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
41 	{ 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
42 	{ 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
43 	{ 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
44 	{ 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
45 	{ 0, 0, 0, 0, 0 },
46 };
47 
48 static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
49 	/* 28.224 Mhz */
50 	{ 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
51 	{ 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
52 	{ 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
53 	{ 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
54 	{ 2822400, 0x145, 0x1, 0x10001, 0x2000 },
55 	{ 3072000, 0x514, 0x187, 0x10042, 0x2000 },
56 	{ 2116800, 0x514, 0x42, 0x10001, 0x2000 },
57 	{ 2304000, 0x619, 0x82, 0x10001, 0x2000 },
58 	{ 0, 0, 0, 0, 0 },
59 };
60 
61 struct i2s_pll_clk {
62 	void __iomem *base;
63 	struct clk_hw hw;
64 	struct device *dev;
65 };
66 
67 static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
68 		unsigned int val)
69 {
70 	writel_relaxed(val, clk->base + reg);
71 }
72 
73 static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
74 		unsigned int reg)
75 {
76 	return readl_relaxed(clk->base + reg);
77 }
78 
79 static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
80 {
81 	return container_of(hw, struct i2s_pll_clk, hw);
82 }
83 
84 static inline unsigned int i2s_pll_get_value(unsigned int val)
85 {
86 	return (val & 0x3F) + ((val >> 6) & 0x3F);
87 }
88 
89 static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
90 {
91 	switch (prate) {
92 	case 27000000:
93 		return i2s_pll_cfg_27m;
94 	case 28224000:
95 		return i2s_pll_cfg_28m;
96 	default:
97 		return NULL;
98 	}
99 }
100 
101 static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
102 			unsigned long parent_rate)
103 {
104 	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
105 	unsigned int idiv, fbdiv, odiv;
106 
107 	idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG));
108 	fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
109 	odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
110 
111 	return ((parent_rate / idiv) * fbdiv) / odiv;
112 }
113 
114 static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
115 			unsigned long *prate)
116 {
117 	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
118 	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
119 	int i;
120 
121 	if (!pll_cfg) {
122 		dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
123 		return -EINVAL;
124 	}
125 
126 	for (i = 0; pll_cfg[i].rate != 0; i++)
127 		if (pll_cfg[i].rate == rate)
128 			return rate;
129 
130 	return -EINVAL;
131 }
132 
133 static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
134 			unsigned long parent_rate)
135 {
136 	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
137 	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
138 	int i;
139 
140 	if (!pll_cfg) {
141 		dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
142 		return -EINVAL;
143 	}
144 
145 	for (i = 0; pll_cfg[i].rate != 0; i++) {
146 		if (pll_cfg[i].rate == rate) {
147 			i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
148 			i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
149 			i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
150 			i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
151 			return 0;
152 		}
153 	}
154 
155 	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
156 			parent_rate);
157 	return -EINVAL;
158 }
159 
160 static const struct clk_ops i2s_pll_ops = {
161 	.recalc_rate = i2s_pll_recalc_rate,
162 	.round_rate = i2s_pll_round_rate,
163 	.set_rate = i2s_pll_set_rate,
164 };
165 
166 static int i2s_pll_clk_probe(struct platform_device *pdev)
167 {
168 	struct device *dev = &pdev->dev;
169 	struct device_node *node = dev->of_node;
170 	const char *clk_name;
171 	const char *parent_name;
172 	struct clk *clk;
173 	struct i2s_pll_clk *pll_clk;
174 	struct clk_init_data init;
175 	struct resource *mem;
176 
177 	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
178 	if (!pll_clk)
179 		return -ENOMEM;
180 
181 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
182 	pll_clk->base = devm_ioremap_resource(dev, mem);
183 	if (IS_ERR(pll_clk->base))
184 		return PTR_ERR(pll_clk->base);
185 
186 	memset(&init, 0, sizeof(init));
187 	clk_name = node->name;
188 	init.name = clk_name;
189 	init.ops = &i2s_pll_ops;
190 	parent_name = of_clk_get_parent_name(node, 0);
191 	init.parent_names = &parent_name;
192 	init.num_parents = 1;
193 	pll_clk->hw.init = &init;
194 	pll_clk->dev = dev;
195 
196 	clk = devm_clk_register(dev, &pll_clk->hw);
197 	if (IS_ERR(clk)) {
198 		dev_err(dev, "failed to register %s clock (%ld)\n",
199 				clk_name, PTR_ERR(clk));
200 		return PTR_ERR(clk);
201 	}
202 
203 	return of_clk_add_provider(node, of_clk_src_simple_get, clk);
204 }
205 
206 static int i2s_pll_clk_remove(struct platform_device *pdev)
207 {
208 	of_clk_del_provider(pdev->dev.of_node);
209 	return 0;
210 }
211 
212 static const struct of_device_id i2s_pll_clk_id[] = {
213 	{ .compatible = "snps,axs10x-i2s-pll-clock", },
214 	{ },
215 };
216 MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
217 
218 static struct platform_driver i2s_pll_clk_driver = {
219 	.driver = {
220 		.name = "axs10x-i2s-pll-clock",
221 		.of_match_table = i2s_pll_clk_id,
222 	},
223 	.probe = i2s_pll_clk_probe,
224 	.remove = i2s_pll_clk_remove,
225 };
226 module_platform_driver(i2s_pll_clk_driver);
227 
228 MODULE_AUTHOR("Jose Abreu <joabreu@synopsys.com>");
229 MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
230 MODULE_LICENSE("GPL v2");
231