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ce44bf5b | 1 | /* Copyright (c) 2009-2013, The Linux Foundation. All rights reserved. |
e44b0cee KH |
2 | * Copyright (c) 2010, Google Inc. |
3 | * | |
4 | * Original authors: Code Aurora Forum | |
5 | * | |
6 | * Author: Dima Zavin <dima@android.com> | |
7 | * - Largely rewritten from original to not be an i2c driver. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 and | |
11 | * only version 2 as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | */ | |
18 | ||
19 | #define pr_fmt(fmt) "%s: " fmt, __func__ | |
20 | ||
21 | #include <linux/delay.h> | |
22 | #include <linux/err.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/slab.h> | |
ce44bf5b | 27 | #include <linux/ssbi.h> |
e44b0cee | 28 | #include <linux/module.h> |
97f00f71 DB |
29 | #include <linux/of.h> |
30 | #include <linux/of_device.h> | |
e44b0cee KH |
31 | |
32 | /* SSBI 2.0 controller registers */ | |
33 | #define SSBI2_CMD 0x0008 | |
34 | #define SSBI2_RD 0x0010 | |
35 | #define SSBI2_STATUS 0x0014 | |
36 | #define SSBI2_MODE2 0x001C | |
37 | ||
38 | /* SSBI_CMD fields */ | |
39 | #define SSBI_CMD_RDWRN (1 << 24) | |
40 | ||
41 | /* SSBI_STATUS fields */ | |
42 | #define SSBI_STATUS_RD_READY (1 << 2) | |
43 | #define SSBI_STATUS_READY (1 << 1) | |
44 | #define SSBI_STATUS_MCHN_BUSY (1 << 0) | |
45 | ||
46 | /* SSBI_MODE2 fields */ | |
47 | #define SSBI_MODE2_REG_ADDR_15_8_SHFT 0x04 | |
48 | #define SSBI_MODE2_REG_ADDR_15_8_MASK (0x7f << SSBI_MODE2_REG_ADDR_15_8_SHFT) | |
49 | ||
50 | #define SET_SSBI_MODE2_REG_ADDR_15_8(MD, AD) \ | |
51 | (((MD) & 0x0F) | ((((AD) >> 8) << SSBI_MODE2_REG_ADDR_15_8_SHFT) & \ | |
52 | SSBI_MODE2_REG_ADDR_15_8_MASK)) | |
53 | ||
54 | /* SSBI PMIC Arbiter command registers */ | |
55 | #define SSBI_PA_CMD 0x0000 | |
56 | #define SSBI_PA_RD_STATUS 0x0004 | |
57 | ||
58 | /* SSBI_PA_CMD fields */ | |
59 | #define SSBI_PA_CMD_RDWRN (1 << 24) | |
60 | #define SSBI_PA_CMD_ADDR_MASK 0x7fff /* REG_ADDR_7_0, REG_ADDR_8_14*/ | |
61 | ||
62 | /* SSBI_PA_RD_STATUS fields */ | |
63 | #define SSBI_PA_RD_STATUS_TRANS_DONE (1 << 27) | |
64 | #define SSBI_PA_RD_STATUS_TRANS_DENIED (1 << 26) | |
65 | ||
66 | #define SSBI_TIMEOUT_US 100 | |
67 | ||
bae911a0 SB |
68 | enum ssbi_controller_type { |
69 | MSM_SBI_CTRL_SSBI = 0, | |
70 | MSM_SBI_CTRL_SSBI2, | |
71 | MSM_SBI_CTRL_PMIC_ARBITER, | |
72 | }; | |
73 | ||
ce44bf5b | 74 | struct ssbi { |
e44b0cee KH |
75 | struct device *slave; |
76 | void __iomem *base; | |
77 | spinlock_t lock; | |
ce44bf5b DB |
78 | enum ssbi_controller_type controller_type; |
79 | int (*read)(struct ssbi *, u16 addr, u8 *buf, int len); | |
5eec14cc | 80 | int (*write)(struct ssbi *, u16 addr, const u8 *buf, int len); |
e44b0cee KH |
81 | }; |
82 | ||
ce44bf5b | 83 | #define to_ssbi(dev) platform_get_drvdata(to_platform_device(dev)) |
e44b0cee | 84 | |
ce44bf5b | 85 | static inline u32 ssbi_readl(struct ssbi *ssbi, u32 reg) |
e44b0cee KH |
86 | { |
87 | return readl(ssbi->base + reg); | |
88 | } | |
89 | ||
ce44bf5b | 90 | static inline void ssbi_writel(struct ssbi *ssbi, u32 val, u32 reg) |
e44b0cee KH |
91 | { |
92 | writel(val, ssbi->base + reg); | |
93 | } | |
94 | ||
3f7a73b5 DB |
95 | /* |
96 | * Via private exchange with one of the original authors, the hardware | |
97 | * should generally finish a transaction in about 5us. The worst | |
98 | * case, is when using the arbiter and both other CPUs have just | |
99 | * started trying to use the SSBI bus will result in a time of about | |
100 | * 20us. It should never take longer than this. | |
101 | * | |
102 | * As such, this wait merely spins, with a udelay. | |
103 | */ | |
ce44bf5b | 104 | static int ssbi_wait_mask(struct ssbi *ssbi, u32 set_mask, u32 clr_mask) |
e44b0cee KH |
105 | { |
106 | u32 timeout = SSBI_TIMEOUT_US; | |
107 | u32 val; | |
108 | ||
109 | while (timeout--) { | |
110 | val = ssbi_readl(ssbi, SSBI2_STATUS); | |
111 | if (((val & set_mask) == set_mask) && ((val & clr_mask) == 0)) | |
112 | return 0; | |
113 | udelay(1); | |
114 | } | |
115 | ||
e44b0cee KH |
116 | return -ETIMEDOUT; |
117 | } | |
118 | ||
119 | static int | |
ce44bf5b | 120 | ssbi_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len) |
e44b0cee KH |
121 | { |
122 | u32 cmd = SSBI_CMD_RDWRN | ((addr & 0xff) << 16); | |
123 | int ret = 0; | |
124 | ||
125 | if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) { | |
126 | u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2); | |
127 | mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr); | |
128 | ssbi_writel(ssbi, mode2, SSBI2_MODE2); | |
129 | } | |
130 | ||
131 | while (len) { | |
132 | ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0); | |
133 | if (ret) | |
134 | goto err; | |
135 | ||
136 | ssbi_writel(ssbi, cmd, SSBI2_CMD); | |
137 | ret = ssbi_wait_mask(ssbi, SSBI_STATUS_RD_READY, 0); | |
138 | if (ret) | |
139 | goto err; | |
140 | *buf++ = ssbi_readl(ssbi, SSBI2_RD) & 0xff; | |
141 | len--; | |
142 | } | |
143 | ||
144 | err: | |
145 | return ret; | |
146 | } | |
147 | ||
148 | static int | |
5eec14cc | 149 | ssbi_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len) |
e44b0cee KH |
150 | { |
151 | int ret = 0; | |
152 | ||
153 | if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) { | |
154 | u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2); | |
155 | mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr); | |
156 | ssbi_writel(ssbi, mode2, SSBI2_MODE2); | |
157 | } | |
158 | ||
159 | while (len) { | |
160 | ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0); | |
161 | if (ret) | |
162 | goto err; | |
163 | ||
164 | ssbi_writel(ssbi, ((addr & 0xff) << 16) | *buf, SSBI2_CMD); | |
165 | ret = ssbi_wait_mask(ssbi, 0, SSBI_STATUS_MCHN_BUSY); | |
166 | if (ret) | |
167 | goto err; | |
168 | buf++; | |
169 | len--; | |
170 | } | |
171 | ||
172 | err: | |
173 | return ret; | |
174 | } | |
175 | ||
3f7a73b5 DB |
176 | /* |
177 | * See ssbi_wait_mask for an explanation of the time and the | |
178 | * busywait. | |
179 | */ | |
e44b0cee | 180 | static inline int |
ce44bf5b | 181 | ssbi_pa_transfer(struct ssbi *ssbi, u32 cmd, u8 *data) |
e44b0cee KH |
182 | { |
183 | u32 timeout = SSBI_TIMEOUT_US; | |
184 | u32 rd_status = 0; | |
185 | ||
186 | ssbi_writel(ssbi, cmd, SSBI_PA_CMD); | |
187 | ||
188 | while (timeout--) { | |
189 | rd_status = ssbi_readl(ssbi, SSBI_PA_RD_STATUS); | |
190 | ||
37799ef4 | 191 | if (rd_status & SSBI_PA_RD_STATUS_TRANS_DENIED) |
e44b0cee | 192 | return -EPERM; |
e44b0cee KH |
193 | |
194 | if (rd_status & SSBI_PA_RD_STATUS_TRANS_DONE) { | |
195 | if (data) | |
196 | *data = rd_status & 0xff; | |
197 | return 0; | |
198 | } | |
199 | udelay(1); | |
200 | } | |
201 | ||
e44b0cee KH |
202 | return -ETIMEDOUT; |
203 | } | |
204 | ||
205 | static int | |
ce44bf5b | 206 | ssbi_pa_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len) |
e44b0cee KH |
207 | { |
208 | u32 cmd; | |
209 | int ret = 0; | |
210 | ||
211 | cmd = SSBI_PA_CMD_RDWRN | (addr & SSBI_PA_CMD_ADDR_MASK) << 8; | |
212 | ||
213 | while (len) { | |
ce44bf5b | 214 | ret = ssbi_pa_transfer(ssbi, cmd, buf); |
e44b0cee KH |
215 | if (ret) |
216 | goto err; | |
217 | buf++; | |
218 | len--; | |
219 | } | |
220 | ||
221 | err: | |
222 | return ret; | |
223 | } | |
224 | ||
225 | static int | |
5eec14cc | 226 | ssbi_pa_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len) |
e44b0cee KH |
227 | { |
228 | u32 cmd; | |
229 | int ret = 0; | |
230 | ||
231 | while (len) { | |
232 | cmd = (addr & SSBI_PA_CMD_ADDR_MASK) << 8 | *buf; | |
ce44bf5b | 233 | ret = ssbi_pa_transfer(ssbi, cmd, NULL); |
e44b0cee KH |
234 | if (ret) |
235 | goto err; | |
236 | buf++; | |
237 | len--; | |
238 | } | |
239 | ||
240 | err: | |
241 | return ret; | |
242 | } | |
243 | ||
ce44bf5b | 244 | int ssbi_read(struct device *dev, u16 addr, u8 *buf, int len) |
e44b0cee | 245 | { |
ce44bf5b | 246 | struct ssbi *ssbi = to_ssbi(dev); |
e44b0cee KH |
247 | unsigned long flags; |
248 | int ret; | |
249 | ||
e44b0cee KH |
250 | spin_lock_irqsave(&ssbi->lock, flags); |
251 | ret = ssbi->read(ssbi, addr, buf, len); | |
252 | spin_unlock_irqrestore(&ssbi->lock, flags); | |
253 | ||
254 | return ret; | |
255 | } | |
ce44bf5b | 256 | EXPORT_SYMBOL_GPL(ssbi_read); |
e44b0cee | 257 | |
5eec14cc | 258 | int ssbi_write(struct device *dev, u16 addr, const u8 *buf, int len) |
e44b0cee | 259 | { |
ce44bf5b | 260 | struct ssbi *ssbi = to_ssbi(dev); |
e44b0cee KH |
261 | unsigned long flags; |
262 | int ret; | |
263 | ||
e44b0cee KH |
264 | spin_lock_irqsave(&ssbi->lock, flags); |
265 | ret = ssbi->write(ssbi, addr, buf, len); | |
266 | spin_unlock_irqrestore(&ssbi->lock, flags); | |
267 | ||
268 | return ret; | |
269 | } | |
ce44bf5b | 270 | EXPORT_SYMBOL_GPL(ssbi_write); |
e44b0cee | 271 | |
ce44bf5b | 272 | static int ssbi_probe(struct platform_device *pdev) |
e44b0cee | 273 | { |
97f00f71 | 274 | struct device_node *np = pdev->dev.of_node; |
e44b0cee | 275 | struct resource *mem_res; |
ce44bf5b | 276 | struct ssbi *ssbi; |
97f00f71 | 277 | const char *type; |
e44b0cee | 278 | |
e5784388 SB |
279 | ssbi = devm_kzalloc(&pdev->dev, sizeof(*ssbi), GFP_KERNEL); |
280 | if (!ssbi) | |
e44b0cee | 281 | return -ENOMEM; |
e44b0cee KH |
282 | |
283 | mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
e5784388 SB |
284 | ssbi->base = devm_ioremap_resource(&pdev->dev, mem_res); |
285 | if (IS_ERR(ssbi->base)) | |
286 | return PTR_ERR(ssbi->base); | |
e44b0cee | 287 | |
e44b0cee KH |
288 | platform_set_drvdata(pdev, ssbi); |
289 | ||
97f00f71 DB |
290 | type = of_get_property(np, "qcom,controller-type", NULL); |
291 | if (type == NULL) { | |
e5784388 SB |
292 | dev_err(&pdev->dev, "Missing qcom,controller-type property\n"); |
293 | return -EINVAL; | |
97f00f71 DB |
294 | } |
295 | dev_info(&pdev->dev, "SSBI controller type: '%s'\n", type); | |
296 | if (strcmp(type, "ssbi") == 0) | |
297 | ssbi->controller_type = MSM_SBI_CTRL_SSBI; | |
298 | else if (strcmp(type, "ssbi2") == 0) | |
299 | ssbi->controller_type = MSM_SBI_CTRL_SSBI2; | |
300 | else if (strcmp(type, "pmic-arbiter") == 0) | |
301 | ssbi->controller_type = MSM_SBI_CTRL_PMIC_ARBITER; | |
302 | else { | |
e5784388 SB |
303 | dev_err(&pdev->dev, "Unknown qcom,controller-type\n"); |
304 | return -EINVAL; | |
97f00f71 DB |
305 | } |
306 | ||
e44b0cee | 307 | if (ssbi->controller_type == MSM_SBI_CTRL_PMIC_ARBITER) { |
ce44bf5b DB |
308 | ssbi->read = ssbi_pa_read_bytes; |
309 | ssbi->write = ssbi_pa_write_bytes; | |
e44b0cee | 310 | } else { |
ce44bf5b DB |
311 | ssbi->read = ssbi_read_bytes; |
312 | ssbi->write = ssbi_write_bytes; | |
e44b0cee KH |
313 | } |
314 | ||
315 | spin_lock_init(&ssbi->lock); | |
316 | ||
e5784388 | 317 | return of_platform_populate(np, NULL, NULL, &pdev->dev); |
e44b0cee KH |
318 | } |
319 | ||
12eda2a2 | 320 | static const struct of_device_id ssbi_match_table[] = { |
97f00f71 DB |
321 | { .compatible = "qcom,ssbi" }, |
322 | {} | |
323 | }; | |
6378c1e5 | 324 | MODULE_DEVICE_TABLE(of, ssbi_match_table); |
97f00f71 | 325 | |
ce44bf5b DB |
326 | static struct platform_driver ssbi_driver = { |
327 | .probe = ssbi_probe, | |
e44b0cee | 328 | .driver = { |
ce44bf5b | 329 | .name = "ssbi", |
97f00f71 | 330 | .of_match_table = ssbi_match_table, |
e44b0cee KH |
331 | }, |
332 | }; | |
e5784388 | 333 | module_platform_driver(ssbi_driver); |
e44b0cee KH |
334 | |
335 | MODULE_LICENSE("GPL v2"); | |
336 | MODULE_VERSION("1.0"); | |
ce44bf5b | 337 | MODULE_ALIAS("platform:ssbi"); |
e44b0cee | 338 | MODULE_AUTHOR("Dima Zavin <dima@android.com>"); |