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11#include <linux/clk-provider.h>
12#include <linux/delay.h>
13#include <linux/kernel.h>
14#include <linux/mfd/syscon.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18
19#define LPC18XX_CREG_CREG0 0x004
20#define LPC18XX_CREG_CREG0_EN1KHZ BIT(0)
21#define LPC18XX_CREG_CREG0_EN32KHZ BIT(1)
22#define LPC18XX_CREG_CREG0_RESET32KHZ BIT(2)
23#define LPC18XX_CREG_CREG0_PD32KHZ BIT(3)
24
25#define to_clk_creg(_hw) container_of(_hw, struct clk_creg_data, hw)
26
27enum {
28 CREG_CLK_1KHZ,
29 CREG_CLK_32KHZ,
30 CREG_CLK_MAX,
31};
32
33struct clk_creg_data {
34 struct clk_hw hw;
35 const char *name;
36 struct regmap *reg;
37 unsigned int en_mask;
38 const struct clk_ops *ops;
39};
40
41#define CREG_CLK(_name, _emask, _ops) \
42{ \
43 .name = _name, \
44 .en_mask = LPC18XX_CREG_CREG0_##_emask, \
45 .ops = &_ops, \
46}
47
48static int clk_creg_32k_prepare(struct clk_hw *hw)
49{
50 struct clk_creg_data *creg = to_clk_creg(hw);
51 int ret;
52
53 ret = regmap_update_bits(creg->reg, LPC18XX_CREG_CREG0,
54 LPC18XX_CREG_CREG0_PD32KHZ |
55 LPC18XX_CREG_CREG0_RESET32KHZ, 0);
56
57
58
59
60
61 msleep(2500);
62
63 return ret;
64}
65
66static void clk_creg_32k_unprepare(struct clk_hw *hw)
67{
68 struct clk_creg_data *creg = to_clk_creg(hw);
69
70 regmap_update_bits(creg->reg, LPC18XX_CREG_CREG0,
71 LPC18XX_CREG_CREG0_PD32KHZ,
72 LPC18XX_CREG_CREG0_PD32KHZ);
73}
74
75static int clk_creg_32k_is_prepared(struct clk_hw *hw)
76{
77 struct clk_creg_data *creg = to_clk_creg(hw);
78 u32 reg;
79
80 regmap_read(creg->reg, LPC18XX_CREG_CREG0, ®);
81
82 return !(reg & LPC18XX_CREG_CREG0_PD32KHZ) &&
83 !(reg & LPC18XX_CREG_CREG0_RESET32KHZ);
84}
85
86static unsigned long clk_creg_1k_recalc_rate(struct clk_hw *hw,
87 unsigned long parent_rate)
88{
89 return parent_rate / 32;
90}
91
92static int clk_creg_enable(struct clk_hw *hw)
93{
94 struct clk_creg_data *creg = to_clk_creg(hw);
95
96 return regmap_update_bits(creg->reg, LPC18XX_CREG_CREG0,
97 creg->en_mask, creg->en_mask);
98}
99
100static void clk_creg_disable(struct clk_hw *hw)
101{
102 struct clk_creg_data *creg = to_clk_creg(hw);
103
104 regmap_update_bits(creg->reg, LPC18XX_CREG_CREG0,
105 creg->en_mask, 0);
106}
107
108static int clk_creg_is_enabled(struct clk_hw *hw)
109{
110 struct clk_creg_data *creg = to_clk_creg(hw);
111 u32 reg;
112
113 regmap_read(creg->reg, LPC18XX_CREG_CREG0, ®);
114
115 return !!(reg & creg->en_mask);
116}
117
118static const struct clk_ops clk_creg_32k = {
119 .enable = clk_creg_enable,
120 .disable = clk_creg_disable,
121 .is_enabled = clk_creg_is_enabled,
122 .prepare = clk_creg_32k_prepare,
123 .unprepare = clk_creg_32k_unprepare,
124 .is_prepared = clk_creg_32k_is_prepared,
125};
126
127static const struct clk_ops clk_creg_1k = {
128 .enable = clk_creg_enable,
129 .disable = clk_creg_disable,
130 .is_enabled = clk_creg_is_enabled,
131 .recalc_rate = clk_creg_1k_recalc_rate,
132};
133
134static struct clk_creg_data clk_creg_clocks[] = {
135 [CREG_CLK_1KHZ] = CREG_CLK("1khz_clk", EN1KHZ, clk_creg_1k),
136 [CREG_CLK_32KHZ] = CREG_CLK("32khz_clk", EN32KHZ, clk_creg_32k),
137};
138
139static struct clk *clk_register_creg_clk(struct device *dev,
140 struct clk_creg_data *creg_clk,
141 const char **parent_name,
142 struct regmap *syscon)
143{
144 struct clk_init_data init;
145
146 init.ops = creg_clk->ops;
147 init.name = creg_clk->name;
148 init.parent_names = parent_name;
149 init.num_parents = 1;
150 init.flags = 0;
151
152 creg_clk->reg = syscon;
153 creg_clk->hw.init = &init;
154
155 if (dev)
156 return devm_clk_register(dev, &creg_clk->hw);
157
158 return clk_register(NULL, &creg_clk->hw);
159}
160
161static struct clk *clk_creg_early[CREG_CLK_MAX];
162static struct clk_onecell_data clk_creg_early_data = {
163 .clks = clk_creg_early,
164 .clk_num = CREG_CLK_MAX,
165};
166
167static void __init lpc18xx_creg_clk_init(struct device_node *np)
168{
169 const char *clk_32khz_parent;
170 struct regmap *syscon;
171
172 syscon = syscon_node_to_regmap(np->parent);
173 if (IS_ERR(syscon)) {
174 pr_err("%s: syscon lookup failed\n", __func__);
175 return;
176 }
177
178 clk_32khz_parent = of_clk_get_parent_name(np, 0);
179
180 clk_creg_early[CREG_CLK_32KHZ] =
181 clk_register_creg_clk(NULL, &clk_creg_clocks[CREG_CLK_32KHZ],
182 &clk_32khz_parent, syscon);
183 clk_creg_early[CREG_CLK_1KHZ] = ERR_PTR(-EPROBE_DEFER);
184
185 of_clk_add_provider(np, of_clk_src_onecell_get, &clk_creg_early_data);
186}
187CLK_OF_DECLARE_DRIVER(lpc18xx_creg_clk, "nxp,lpc1850-creg-clk",
188 lpc18xx_creg_clk_init);
189
190static struct clk *clk_creg[CREG_CLK_MAX];
191static struct clk_onecell_data clk_creg_data = {
192 .clks = clk_creg,
193 .clk_num = CREG_CLK_MAX,
194};
195
196static int lpc18xx_creg_clk_probe(struct platform_device *pdev)
197{
198 struct device_node *np = pdev->dev.of_node;
199 struct regmap *syscon;
200
201 syscon = syscon_node_to_regmap(np->parent);
202 if (IS_ERR(syscon)) {
203 dev_err(&pdev->dev, "syscon lookup failed\n");
204 return PTR_ERR(syscon);
205 }
206
207 clk_creg[CREG_CLK_32KHZ] = clk_creg_early[CREG_CLK_32KHZ];
208 clk_creg[CREG_CLK_1KHZ] =
209 clk_register_creg_clk(NULL, &clk_creg_clocks[CREG_CLK_1KHZ],
210 &clk_creg_clocks[CREG_CLK_32KHZ].name,
211 syscon);
212
213 return of_clk_add_provider(np, of_clk_src_onecell_get, &clk_creg_data);
214}
215
216static const struct of_device_id lpc18xx_creg_clk_of_match[] = {
217 { .compatible = "nxp,lpc1850-creg-clk" },
218 {},
219};
220
221static struct platform_driver lpc18xx_creg_clk_driver = {
222 .probe = lpc18xx_creg_clk_probe,
223 .driver = {
224 .name = "lpc18xx-creg-clk",
225 .of_match_table = lpc18xx_creg_clk_of_match,
226 },
227};
228builtin_platform_driver(lpc18xx_creg_clk_driver);
229
