1// SPDX-License-Identifier: GPL-2.0
2/*
3 * MVEBU Core divider clock
4 *
5 * Copyright (C) 2013 Marvell
6 *
7 * Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
8 *
9 */
10
11#include <linux/kernel.h>
12#include <linux/clk-provider.h>
13#include <linux/io.h>
14#include <linux/of_address.h>
15#include <linux/slab.h>
16#include <linux/delay.h>
17#include "common.h"
18
19#define CORE_CLK_DIV_RATIO_MASK 0xff
20
21/*
22 * This structure describes the hardware details (bit offset and mask)
23 * to configure one particular core divider clock. Those hardware
24 * details may differ from one SoC to another. This structure is
25 * therefore typically instantiated statically to describe the
26 * hardware details.
27 */
28struct clk_corediv_desc {
29 unsigned int mask;
30 unsigned int offset;
31 unsigned int fieldbit;
32};
33
34/*
35 * This structure describes the hardware details to configure the core
36 * divider clocks on a given SoC. Amongst others, it points to the
37 * array of core divider clock descriptors for this SoC, as well as
38 * the corresponding operations to manipulate them.
39 */
40struct clk_corediv_soc_desc {
41 const struct clk_corediv_desc *descs;
42 unsigned int ndescs;
43 const struct clk_ops ops;
44 u32 ratio_reload;
45 u32 enable_bit_offset;
46 u32 ratio_offset;
47};
48
49/*
50 * This structure represents one core divider clock for the clock
51 * framework, and is dynamically allocated for each core divider clock
52 * existing in the current SoC.
53 */
54struct clk_corediv {
55 struct clk_hw hw;
56 void __iomem *reg;
57 const struct clk_corediv_desc *desc;
58 const struct clk_corediv_soc_desc *soc_desc;
59 spinlock_t lock;
60};
61
62static struct clk_onecell_data clk_data;
63
64/*
65 * Description of the core divider clocks available. For now, we
66 * support only NAND, and it is available at the same register
67 * locations regardless of the SoC.
68 */
69static const struct clk_corediv_desc mvebu_corediv_desc[] = {
70 { .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */
71};
72
73static const struct clk_corediv_desc mv98dx3236_corediv_desc[] = {
74 { .mask = 0x0f, .offset = 6, .fieldbit = 27 }, /* NAND clock */
75};
76
77#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)
78
79static int clk_corediv_is_enabled(struct clk_hw *hwclk)
80{
81 struct clk_corediv *corediv = to_corediv_clk(hwclk);
82 const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
83 const struct clk_corediv_desc *desc = corediv->desc;
84 u32 enable_mask = BIT(desc->fieldbit) << soc_desc->enable_bit_offset;
85
86 return !!(readl(addr: corediv->reg) & enable_mask);
87}
88
89static int clk_corediv_enable(struct clk_hw *hwclk)
90{
91 struct clk_corediv *corediv = to_corediv_clk(hwclk);
92 const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
93 const struct clk_corediv_desc *desc = corediv->desc;
94 unsigned long flags = 0;
95 u32 reg;
96
97 spin_lock_irqsave(&corediv->lock, flags);
98
99 reg = readl(addr: corediv->reg);
100 reg |= (BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
101 writel(val: reg, addr: corediv->reg);
102
103 spin_unlock_irqrestore(lock: &corediv->lock, flags);
104
105 return 0;
106}
107
108static void clk_corediv_disable(struct clk_hw *hwclk)
109{
110 struct clk_corediv *corediv = to_corediv_clk(hwclk);
111 const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
112 const struct clk_corediv_desc *desc = corediv->desc;
113 unsigned long flags = 0;
114 u32 reg;
115
116 spin_lock_irqsave(&corediv->lock, flags);
117
118 reg = readl(addr: corediv->reg);
119 reg &= ~(BIT(desc->fieldbit) << soc_desc->enable_bit_offset);
120 writel(val: reg, addr: corediv->reg);
121
122 spin_unlock_irqrestore(lock: &corediv->lock, flags);
123}
124
125static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk,
126 unsigned long parent_rate)
127{
128 struct clk_corediv *corediv = to_corediv_clk(hwclk);
129 const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
130 const struct clk_corediv_desc *desc = corediv->desc;
131 u32 reg, div;
132
133 reg = readl(addr: corediv->reg + soc_desc->ratio_offset);
134 div = (reg >> desc->offset) & desc->mask;
135 return parent_rate / div;
136}
137
138static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate,
139 unsigned long *parent_rate)
140{
141 /* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
142 u32 div;
143
144 div = *parent_rate / rate;
145 if (div < 4)
146 div = 4;
147 else if (div > 6)
148 div = 8;
149
150 return *parent_rate / div;
151}
152
153static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
154 unsigned long parent_rate)
155{
156 struct clk_corediv *corediv = to_corediv_clk(hwclk);
157 const struct clk_corediv_soc_desc *soc_desc = corediv->soc_desc;
158 const struct clk_corediv_desc *desc = corediv->desc;
159 unsigned long flags = 0;
160 u32 reg, div;
161
162 div = parent_rate / rate;
163
164 spin_lock_irqsave(&corediv->lock, flags);
165
166 /* Write new divider to the divider ratio register */
167 reg = readl(addr: corediv->reg + soc_desc->ratio_offset);
168 reg &= ~(desc->mask << desc->offset);
169 reg |= (div & desc->mask) << desc->offset;
170 writel(val: reg, addr: corediv->reg + soc_desc->ratio_offset);
171
172 /* Set reload-force for this clock */
173 reg = readl(addr: corediv->reg) | BIT(desc->fieldbit);
174 writel(val: reg, addr: corediv->reg);
175
176 /* Now trigger the clock update */
177 reg = readl(addr: corediv->reg) | soc_desc->ratio_reload;
178 writel(val: reg, addr: corediv->reg);
179
180 /*
181 * Wait for clocks to settle down, and then clear all the
182 * ratios request and the reload request.
183 */
184 udelay(1000);
185 reg &= ~(CORE_CLK_DIV_RATIO_MASK | soc_desc->ratio_reload);
186 writel(val: reg, addr: corediv->reg);
187 udelay(1000);
188
189 spin_unlock_irqrestore(lock: &corediv->lock, flags);
190
191 return 0;
192}
193
194static const struct clk_corediv_soc_desc armada370_corediv_soc = {
195 .descs = mvebu_corediv_desc,
196 .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
197 .ops = {
198 .enable = clk_corediv_enable,
199 .disable = clk_corediv_disable,
200 .is_enabled = clk_corediv_is_enabled,
201 .recalc_rate = clk_corediv_recalc_rate,
202 .round_rate = clk_corediv_round_rate,
203 .set_rate = clk_corediv_set_rate,
204 },
205 .ratio_reload = BIT(8),
206 .enable_bit_offset = 24,
207 .ratio_offset = 0x8,
208};
209
210static const struct clk_corediv_soc_desc armada380_corediv_soc = {
211 .descs = mvebu_corediv_desc,
212 .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
213 .ops = {
214 .enable = clk_corediv_enable,
215 .disable = clk_corediv_disable,
216 .is_enabled = clk_corediv_is_enabled,
217 .recalc_rate = clk_corediv_recalc_rate,
218 .round_rate = clk_corediv_round_rate,
219 .set_rate = clk_corediv_set_rate,
220 },
221 .ratio_reload = BIT(8),
222 .enable_bit_offset = 16,
223 .ratio_offset = 0x4,
224};
225
226static const struct clk_corediv_soc_desc armada375_corediv_soc = {
227 .descs = mvebu_corediv_desc,
228 .ndescs = ARRAY_SIZE(mvebu_corediv_desc),
229 .ops = {
230 .recalc_rate = clk_corediv_recalc_rate,
231 .round_rate = clk_corediv_round_rate,
232 .set_rate = clk_corediv_set_rate,
233 },
234 .ratio_reload = BIT(8),
235 .ratio_offset = 0x4,
236};
237
238static const struct clk_corediv_soc_desc mv98dx3236_corediv_soc = {
239 .descs = mv98dx3236_corediv_desc,
240 .ndescs = ARRAY_SIZE(mv98dx3236_corediv_desc),
241 .ops = {
242 .recalc_rate = clk_corediv_recalc_rate,
243 .round_rate = clk_corediv_round_rate,
244 .set_rate = clk_corediv_set_rate,
245 },
246 .ratio_reload = BIT(10),
247 .ratio_offset = 0x8,
248};
249
250static void __init
251mvebu_corediv_clk_init(struct device_node *node,
252 const struct clk_corediv_soc_desc *soc_desc)
253{
254 struct clk_init_data init;
255 struct clk_corediv *corediv;
256 struct clk **clks;
257 void __iomem *base;
258 const char *parent_name;
259 const char *clk_name;
260 int i;
261
262 base = of_iomap(node, index: 0);
263 if (WARN_ON(!base))
264 return;
265
266 parent_name = of_clk_get_parent_name(np: node, index: 0);
267
268 clk_data.clk_num = soc_desc->ndescs;
269
270 /* clks holds the clock array */
271 clks = kcalloc(n: clk_data.clk_num, size: sizeof(struct clk *),
272 GFP_KERNEL);
273 if (WARN_ON(!clks))
274 goto err_unmap;
275 /* corediv holds the clock specific array */
276 corediv = kcalloc(n: clk_data.clk_num, size: sizeof(struct clk_corediv),
277 GFP_KERNEL);
278 if (WARN_ON(!corediv))
279 goto err_free_clks;
280
281 spin_lock_init(&corediv->lock);
282
283 for (i = 0; i < clk_data.clk_num; i++) {
284 of_property_read_string_index(np: node, propname: "clock-output-names",
285 index: i, output: &clk_name);
286 init.num_parents = 1;
287 init.parent_names = &parent_name;
288 init.name = clk_name;
289 init.ops = &soc_desc->ops;
290 init.flags = 0;
291
292 corediv[i].soc_desc = soc_desc;
293 corediv[i].desc = soc_desc->descs + i;
294 corediv[i].reg = base;
295 corediv[i].hw.init = &init;
296
297 clks[i] = clk_register(NULL, hw: &corediv[i].hw);
298 WARN_ON(IS_ERR(clks[i]));
299 }
300
301 clk_data.clks = clks;
302 of_clk_add_provider(np: node, clk_src_get: of_clk_src_onecell_get, data: &clk_data);
303 return;
304
305err_free_clks:
306 kfree(objp: clks);
307err_unmap:
308 iounmap(addr: base);
309}
310
311static void __init armada370_corediv_clk_init(struct device_node *node)
312{
313 return mvebu_corediv_clk_init(node, soc_desc: &armada370_corediv_soc);
314}
315CLK_OF_DECLARE(armada370_corediv_clk, "marvell,armada-370-corediv-clock",
316 armada370_corediv_clk_init);
317
318static void __init armada375_corediv_clk_init(struct device_node *node)
319{
320 return mvebu_corediv_clk_init(node, soc_desc: &armada375_corediv_soc);
321}
322CLK_OF_DECLARE(armada375_corediv_clk, "marvell,armada-375-corediv-clock",
323 armada375_corediv_clk_init);
324
325static void __init armada380_corediv_clk_init(struct device_node *node)
326{
327 return mvebu_corediv_clk_init(node, soc_desc: &armada380_corediv_soc);
328}
329CLK_OF_DECLARE(armada380_corediv_clk, "marvell,armada-380-corediv-clock",
330 armada380_corediv_clk_init);
331
332static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
333{
334 return mvebu_corediv_clk_init(node, soc_desc: &mv98dx3236_corediv_soc);
335}
336CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
337 mv98dx3236_corediv_clk_init);
338

source code of linux/drivers/clk/mvebu/clk-corediv.c