1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2014 Chen-Yu Tsai
4 *
5 * Chen-Yu Tsai <wens@csie.org>
6 */
7
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/log2.h>
13
14 #include "clk-factors.h"
15
16
17 /*
18 * sun9i_a80_get_pll4_factors() - calculates n, p, m factors for PLL4
19 * PLL4 rate is calculated as follows
20 * rate = (parent_rate * n >> p) / (m + 1);
21 * parent_rate is always 24MHz
22 *
23 * p and m are named div1 and div2 in Allwinner's SDK
24 */
25
sun9i_a80_get_pll4_factors(struct factors_request * req)26 static void sun9i_a80_get_pll4_factors(struct factors_request *req)
27 {
28 int n;
29 int m = 1;
30 int p = 1;
31
32 /* Normalize value to a 6 MHz multiple (24 MHz / 4) */
33 n = DIV_ROUND_UP(req->rate, 6000000);
34
35 /* If n is too large switch to steps of 12 MHz */
36 if (n > 255) {
37 m = 0;
38 n = (n + 1) / 2;
39 }
40
41 /* If n is still too large switch to steps of 24 MHz */
42 if (n > 255) {
43 p = 0;
44 n = (n + 1) / 2;
45 }
46
47 /* n must be between 12 and 255 */
48 if (n > 255)
49 n = 255;
50 else if (n < 12)
51 n = 12;
52
53 req->rate = ((24000000 * n) >> p) / (m + 1);
54 req->n = n;
55 req->m = m;
56 req->p = p;
57 }
58
59 static const struct clk_factors_config sun9i_a80_pll4_config = {
60 .mshift = 18,
61 .mwidth = 1,
62 .nshift = 8,
63 .nwidth = 8,
64 .pshift = 16,
65 .pwidth = 1,
66 };
67
68 static const struct factors_data sun9i_a80_pll4_data __initconst = {
69 .enable = 31,
70 .table = &sun9i_a80_pll4_config,
71 .getter = sun9i_a80_get_pll4_factors,
72 };
73
74 static DEFINE_SPINLOCK(sun9i_a80_pll4_lock);
75
sun9i_a80_pll4_setup(struct device_node * node)76 static void __init sun9i_a80_pll4_setup(struct device_node *node)
77 {
78 void __iomem *reg;
79
80 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
81 if (IS_ERR(reg)) {
82 pr_err("Could not get registers for a80-pll4-clk: %pOFn\n",
83 node);
84 return;
85 }
86
87 sunxi_factors_register(node, &sun9i_a80_pll4_data,
88 &sun9i_a80_pll4_lock, reg);
89 }
90 CLK_OF_DECLARE(sun9i_a80_pll4, "allwinner,sun9i-a80-pll4-clk", sun9i_a80_pll4_setup);
91
92
93 /*
94 * sun9i_a80_get_gt_factors() - calculates m factor for GT
95 * GT rate is calculated as follows
96 * rate = parent_rate / (m + 1);
97 */
98
sun9i_a80_get_gt_factors(struct factors_request * req)99 static void sun9i_a80_get_gt_factors(struct factors_request *req)
100 {
101 u32 div;
102
103 if (req->parent_rate < req->rate)
104 req->rate = req->parent_rate;
105
106 div = DIV_ROUND_UP(req->parent_rate, req->rate);
107
108 /* maximum divider is 4 */
109 if (div > 4)
110 div = 4;
111
112 req->rate = req->parent_rate / div;
113 req->m = div;
114 }
115
116 static const struct clk_factors_config sun9i_a80_gt_config = {
117 .mshift = 0,
118 .mwidth = 2,
119 };
120
121 static const struct factors_data sun9i_a80_gt_data __initconst = {
122 .mux = 24,
123 .muxmask = BIT(1) | BIT(0),
124 .table = &sun9i_a80_gt_config,
125 .getter = sun9i_a80_get_gt_factors,
126 };
127
128 static DEFINE_SPINLOCK(sun9i_a80_gt_lock);
129
sun9i_a80_gt_setup(struct device_node * node)130 static void __init sun9i_a80_gt_setup(struct device_node *node)
131 {
132 void __iomem *reg;
133
134 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
135 if (IS_ERR(reg)) {
136 pr_err("Could not get registers for a80-gt-clk: %pOFn\n",
137 node);
138 return;
139 }
140
141 /* The GT bus clock needs to be always enabled */
142 sunxi_factors_register_critical(node, &sun9i_a80_gt_data,
143 &sun9i_a80_gt_lock, reg);
144 }
145 CLK_OF_DECLARE(sun9i_a80_gt, "allwinner,sun9i-a80-gt-clk", sun9i_a80_gt_setup);
146
147
148 /*
149 * sun9i_a80_get_ahb_factors() - calculates p factor for AHB0/1/2
150 * AHB rate is calculated as follows
151 * rate = parent_rate >> p;
152 */
153
sun9i_a80_get_ahb_factors(struct factors_request * req)154 static void sun9i_a80_get_ahb_factors(struct factors_request *req)
155 {
156 u32 _p;
157
158 if (req->parent_rate < req->rate)
159 req->rate = req->parent_rate;
160
161 _p = order_base_2(DIV_ROUND_UP(req->parent_rate, req->rate));
162
163 /* maximum p is 3 */
164 if (_p > 3)
165 _p = 3;
166
167 req->rate = req->parent_rate >> _p;
168 req->p = _p;
169 }
170
171 static const struct clk_factors_config sun9i_a80_ahb_config = {
172 .pshift = 0,
173 .pwidth = 2,
174 };
175
176 static const struct factors_data sun9i_a80_ahb_data __initconst = {
177 .mux = 24,
178 .muxmask = BIT(1) | BIT(0),
179 .table = &sun9i_a80_ahb_config,
180 .getter = sun9i_a80_get_ahb_factors,
181 };
182
183 static DEFINE_SPINLOCK(sun9i_a80_ahb_lock);
184
sun9i_a80_ahb_setup(struct device_node * node)185 static void __init sun9i_a80_ahb_setup(struct device_node *node)
186 {
187 void __iomem *reg;
188
189 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
190 if (IS_ERR(reg)) {
191 pr_err("Could not get registers for a80-ahb-clk: %pOFn\n",
192 node);
193 return;
194 }
195
196 sunxi_factors_register(node, &sun9i_a80_ahb_data,
197 &sun9i_a80_ahb_lock, reg);
198 }
199 CLK_OF_DECLARE(sun9i_a80_ahb, "allwinner,sun9i-a80-ahb-clk", sun9i_a80_ahb_setup);
200
201
202 static const struct factors_data sun9i_a80_apb0_data __initconst = {
203 .mux = 24,
204 .muxmask = BIT(0),
205 .table = &sun9i_a80_ahb_config,
206 .getter = sun9i_a80_get_ahb_factors,
207 };
208
209 static DEFINE_SPINLOCK(sun9i_a80_apb0_lock);
210
sun9i_a80_apb0_setup(struct device_node * node)211 static void __init sun9i_a80_apb0_setup(struct device_node *node)
212 {
213 void __iomem *reg;
214
215 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
216 if (IS_ERR(reg)) {
217 pr_err("Could not get registers for a80-apb0-clk: %pOFn\n",
218 node);
219 return;
220 }
221
222 sunxi_factors_register(node, &sun9i_a80_apb0_data,
223 &sun9i_a80_apb0_lock, reg);
224 }
225 CLK_OF_DECLARE(sun9i_a80_apb0, "allwinner,sun9i-a80-apb0-clk", sun9i_a80_apb0_setup);
226
227
228 /*
229 * sun9i_a80_get_apb1_factors() - calculates m, p factors for APB1
230 * APB1 rate is calculated as follows
231 * rate = (parent_rate >> p) / (m + 1);
232 */
233
sun9i_a80_get_apb1_factors(struct factors_request * req)234 static void sun9i_a80_get_apb1_factors(struct factors_request *req)
235 {
236 u32 div;
237
238 if (req->parent_rate < req->rate)
239 req->rate = req->parent_rate;
240
241 div = DIV_ROUND_UP(req->parent_rate, req->rate);
242
243 /* Highest possible divider is 256 (p = 3, m = 31) */
244 if (div > 256)
245 div = 256;
246
247 req->p = order_base_2(div);
248 req->m = (req->parent_rate >> req->p) - 1;
249 req->rate = (req->parent_rate >> req->p) / (req->m + 1);
250 }
251
252 static const struct clk_factors_config sun9i_a80_apb1_config = {
253 .mshift = 0,
254 .mwidth = 5,
255 .pshift = 16,
256 .pwidth = 2,
257 };
258
259 static const struct factors_data sun9i_a80_apb1_data __initconst = {
260 .mux = 24,
261 .muxmask = BIT(0),
262 .table = &sun9i_a80_apb1_config,
263 .getter = sun9i_a80_get_apb1_factors,
264 };
265
266 static DEFINE_SPINLOCK(sun9i_a80_apb1_lock);
267
sun9i_a80_apb1_setup(struct device_node * node)268 static void __init sun9i_a80_apb1_setup(struct device_node *node)
269 {
270 void __iomem *reg;
271
272 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
273 if (IS_ERR(reg)) {
274 pr_err("Could not get registers for a80-apb1-clk: %pOFn\n",
275 node);
276 return;
277 }
278
279 sunxi_factors_register(node, &sun9i_a80_apb1_data,
280 &sun9i_a80_apb1_lock, reg);
281 }
282 CLK_OF_DECLARE(sun9i_a80_apb1, "allwinner,sun9i-a80-apb1-clk", sun9i_a80_apb1_setup);
283