1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Peripheral clock support for AT91 architectures.
4 *
5 * Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
6 *
7 * Author: Claudiu Beznea <claudiu.beznea@microchip.com>
8 *
9 * Based on drivers/clk/at91/clk-peripheral.c from Linux.
10 */
11 #include <common.h>
12 #include <clk-uclass.h>
13 #include <dm.h>
14 #include <linux/io.h>
15 #include <linux/clk-provider.h>
16 #include <linux/clk/at91_pmc.h>
17
18 #include "pmc.h"
19
20 #define UBOOT_DM_CLK_AT91_PERIPH "at91-periph-clk"
21 #define UBOOT_DM_CLK_AT91_SAM9X5_PERIPH "at91-sam9x5-periph-clk"
22
23 #define PERIPHERAL_ID_MIN 2
24 #define PERIPHERAL_ID_MAX 31
25 #define PERIPHERAL_MASK(id) (1 << ((id) & PERIPHERAL_ID_MAX))
26
27 #define PERIPHERAL_MAX_SHIFT 3
28
29 struct clk_peripheral {
30 void __iomem *base;
31 struct clk clk;
32 u32 id;
33 };
34
35 #define to_clk_peripheral(_c) container_of(_c, struct clk_peripheral, clk)
36
37 struct clk_sam9x5_peripheral {
38 const struct clk_pcr_layout *layout;
39 void __iomem *base;
40 struct clk clk;
41 struct clk_range range;
42 u32 id;
43 u32 div;
44 bool auto_div;
45 };
46
47 #define to_clk_sam9x5_peripheral(_c) \
48 container_of(_c, struct clk_sam9x5_peripheral, clk)
49
clk_peripheral_enable(struct clk * clk)50 static int clk_peripheral_enable(struct clk *clk)
51 {
52 struct clk_peripheral *periph = to_clk_peripheral(clk);
53 int offset = AT91_PMC_PCER;
54 u32 id = periph->id;
55
56 if (id < PERIPHERAL_ID_MIN)
57 return 0;
58 if (id > PERIPHERAL_ID_MAX)
59 offset = AT91_PMC_PCER1;
60 pmc_write(periph->base, offset, PERIPHERAL_MASK(id));
61
62 return 0;
63 }
64
clk_peripheral_disable(struct clk * clk)65 static int clk_peripheral_disable(struct clk *clk)
66 {
67 struct clk_peripheral *periph = to_clk_peripheral(clk);
68 int offset = AT91_PMC_PCDR;
69 u32 id = periph->id;
70
71 if (id < PERIPHERAL_ID_MIN)
72 return -EINVAL;
73
74 if (id > PERIPHERAL_ID_MAX)
75 offset = AT91_PMC_PCDR1;
76 pmc_write(periph->base, offset, PERIPHERAL_MASK(id));
77
78 return 0;
79 }
80
81 static const struct clk_ops peripheral_ops = {
82 .enable = clk_peripheral_enable,
83 .disable = clk_peripheral_disable,
84 .get_rate = clk_generic_get_rate,
85 };
86
87 struct clk *
at91_clk_register_peripheral(void __iomem * base,const char * name,const char * parent_name,u32 id)88 at91_clk_register_peripheral(void __iomem *base, const char *name,
89 const char *parent_name, u32 id)
90 {
91 struct clk_peripheral *periph;
92 struct clk *clk;
93 int ret;
94
95 if (!base || !name || !parent_name || id > PERIPHERAL_ID_MAX)
96 return ERR_PTR(-EINVAL);
97
98 periph = kzalloc(sizeof(*periph), GFP_KERNEL);
99 if (!periph)
100 return ERR_PTR(-ENOMEM);
101
102 periph->id = id;
103 periph->base = base;
104
105 clk = &periph->clk;
106 clk->flags = CLK_GET_RATE_NOCACHE;
107 ret = clk_register(clk, UBOOT_DM_CLK_AT91_PERIPH, name, parent_name);
108 if (ret) {
109 kfree(periph);
110 clk = ERR_PTR(ret);
111 }
112
113 return clk;
114 }
115
116 U_BOOT_DRIVER(at91_periph_clk) = {
117 .name = UBOOT_DM_CLK_AT91_PERIPH,
118 .id = UCLASS_CLK,
119 .ops = &peripheral_ops,
120 .flags = DM_FLAG_PRE_RELOC,
121 };
122
clk_sam9x5_peripheral_enable(struct clk * clk)123 static int clk_sam9x5_peripheral_enable(struct clk *clk)
124 {
125 struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(clk);
126
127 if (periph->id < PERIPHERAL_ID_MIN)
128 return 0;
129
130 pmc_write(periph->base, periph->layout->offset,
131 (periph->id & periph->layout->pid_mask));
132 pmc_update_bits(periph->base, periph->layout->offset,
133 periph->layout->cmd | AT91_PMC_PCR_EN,
134 periph->layout->cmd | AT91_PMC_PCR_EN);
135
136 return 0;
137 }
138
clk_sam9x5_peripheral_disable(struct clk * clk)139 static int clk_sam9x5_peripheral_disable(struct clk *clk)
140 {
141 struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(clk);
142
143 if (periph->id < PERIPHERAL_ID_MIN)
144 return -EINVAL;
145
146 pmc_write(periph->base, periph->layout->offset,
147 (periph->id & periph->layout->pid_mask));
148 pmc_update_bits(periph->base, periph->layout->offset,
149 AT91_PMC_PCR_EN | periph->layout->cmd,
150 periph->layout->cmd);
151
152 return 0;
153 }
154
clk_sam9x5_peripheral_get_rate(struct clk * clk)155 static ulong clk_sam9x5_peripheral_get_rate(struct clk *clk)
156 {
157 struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(clk);
158 ulong parent_rate = clk_get_parent_rate(clk);
159 u32 val, shift = ffs(periph->layout->div_mask) - 1;
160
161 if (!parent_rate)
162 return 0;
163
164 pmc_write(periph->base, periph->layout->offset,
165 (periph->id & periph->layout->pid_mask));
166 pmc_read(periph->base, periph->layout->offset, &val);
167 shift = (val & periph->layout->div_mask) >> shift;
168
169 return parent_rate >> shift;
170 }
171
clk_sam9x5_peripheral_set_rate(struct clk * clk,ulong rate)172 static ulong clk_sam9x5_peripheral_set_rate(struct clk *clk, ulong rate)
173 {
174 struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(clk);
175 ulong parent_rate = clk_get_parent_rate(clk);
176 int shift;
177
178 if (!parent_rate)
179 return 0;
180
181 if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) {
182 if (parent_rate == rate)
183 return rate;
184 else
185 return 0;
186 }
187
188 if (periph->range.max && rate > periph->range.max)
189 return 0;
190
191 for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {
192 if (parent_rate >> shift <= rate)
193 break;
194 }
195 if (shift == PERIPHERAL_MAX_SHIFT + 1)
196 return 0;
197
198 pmc_write(periph->base, periph->layout->offset,
199 (periph->id & periph->layout->pid_mask));
200 pmc_update_bits(periph->base, periph->layout->offset,
201 periph->layout->div_mask | periph->layout->cmd,
202 (shift << (ffs(periph->layout->div_mask) - 1)) |
203 periph->layout->cmd);
204
205 return parent_rate >> shift;
206 }
207
208 static const struct clk_ops sam9x5_peripheral_ops = {
209 .enable = clk_sam9x5_peripheral_enable,
210 .disable = clk_sam9x5_peripheral_disable,
211 .get_rate = clk_sam9x5_peripheral_get_rate,
212 .set_rate = clk_sam9x5_peripheral_set_rate,
213 };
214
215 struct clk *
at91_clk_register_sam9x5_peripheral(void __iomem * base,const struct clk_pcr_layout * layout,const char * name,const char * parent_name,u32 id,const struct clk_range * range)216 at91_clk_register_sam9x5_peripheral(void __iomem *base,
217 const struct clk_pcr_layout *layout,
218 const char *name, const char *parent_name,
219 u32 id, const struct clk_range *range)
220 {
221 struct clk_sam9x5_peripheral *periph;
222 struct clk *clk;
223 int ret;
224
225 if (!base || !layout || !name || !parent_name || !range)
226 return ERR_PTR(-EINVAL);
227
228 periph = kzalloc(sizeof(*periph), GFP_KERNEL);
229 if (!periph)
230 return ERR_PTR(-ENOMEM);
231
232 periph->id = id;
233 periph->base = base;
234 periph->layout = layout;
235 periph->range = *range;
236
237 clk = &periph->clk;
238 clk->flags = CLK_GET_RATE_NOCACHE;
239 ret = clk_register(clk, UBOOT_DM_CLK_AT91_SAM9X5_PERIPH, name,
240 parent_name);
241 if (ret) {
242 kfree(periph);
243 clk = ERR_PTR(ret);
244 }
245
246 return clk;
247 }
248
249 U_BOOT_DRIVER(at91_sam9x5_periph_clk) = {
250 .name = UBOOT_DM_CLK_AT91_SAM9X5_PERIPH,
251 .id = UCLASS_CLK,
252 .ops = &sam9x5_peripheral_ops,
253 .flags = DM_FLAG_PRE_RELOC,
254 };
255