Commit | Line | Data |
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8e0cb05b PA |
1 | /* |
2 | * ECAP PWM driver | |
3 | * | |
4 | * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/ | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/clk.h> | |
26 | #include <linux/pm_runtime.h> | |
27 | #include <linux/pwm.h> | |
333b08ee PA |
28 | #include <linux/of_device.h> |
29 | ||
30 | #include "pwm-tipwmss.h" | |
8e0cb05b PA |
31 | |
32 | /* ECAP registers and bits definitions */ | |
33 | #define CAP1 0x08 | |
34 | #define CAP2 0x0C | |
35 | #define CAP3 0x10 | |
36 | #define CAP4 0x14 | |
37 | #define ECCTL2 0x2A | |
454870a4 | 38 | #define ECCTL2_APWM_POL_LOW BIT(10) |
8e0cb05b PA |
39 | #define ECCTL2_APWM_MODE BIT(9) |
40 | #define ECCTL2_SYNC_SEL_DISA (BIT(7) | BIT(6)) | |
41 | #define ECCTL2_TSCTR_FREERUN BIT(4) | |
42 | ||
0d75c203 PA |
43 | struct ecap_context { |
44 | u32 cap3; | |
45 | u32 cap4; | |
46 | u16 ecctl2; | |
47 | }; | |
48 | ||
8e0cb05b PA |
49 | struct ecap_pwm_chip { |
50 | struct pwm_chip chip; | |
51 | unsigned int clk_rate; | |
52 | void __iomem *mmio_base; | |
0d75c203 | 53 | struct ecap_context ctx; |
8e0cb05b PA |
54 | }; |
55 | ||
56 | static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip) | |
57 | { | |
58 | return container_of(chip, struct ecap_pwm_chip, chip); | |
59 | } | |
60 | ||
61 | /* | |
62 | * period_ns = 10^9 * period_cycles / PWM_CLK_RATE | |
63 | * duty_ns = 10^9 * duty_cycles / PWM_CLK_RATE | |
64 | */ | |
65 | static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |
66 | int duty_ns, int period_ns) | |
67 | { | |
68 | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | |
69 | unsigned long long c; | |
70 | unsigned long period_cycles, duty_cycles; | |
71 | unsigned int reg_val; | |
72 | ||
c2d476a9 | 73 | if (period_ns > NSEC_PER_SEC) |
8e0cb05b PA |
74 | return -ERANGE; |
75 | ||
76 | c = pc->clk_rate; | |
77 | c = c * period_ns; | |
78 | do_div(c, NSEC_PER_SEC); | |
79 | period_cycles = (unsigned long)c; | |
80 | ||
81 | if (period_cycles < 1) { | |
82 | period_cycles = 1; | |
83 | duty_cycles = 1; | |
84 | } else { | |
85 | c = pc->clk_rate; | |
86 | c = c * duty_ns; | |
87 | do_div(c, NSEC_PER_SEC); | |
88 | duty_cycles = (unsigned long)c; | |
89 | } | |
90 | ||
91 | pm_runtime_get_sync(pc->chip.dev); | |
92 | ||
93 | reg_val = readw(pc->mmio_base + ECCTL2); | |
94 | ||
95 | /* Configure APWM mode & disable sync option */ | |
96 | reg_val |= ECCTL2_APWM_MODE | ECCTL2_SYNC_SEL_DISA; | |
97 | ||
98 | writew(reg_val, pc->mmio_base + ECCTL2); | |
99 | ||
100 | if (!test_bit(PWMF_ENABLED, &pwm->flags)) { | |
101 | /* Update active registers if not running */ | |
102 | writel(duty_cycles, pc->mmio_base + CAP2); | |
103 | writel(period_cycles, pc->mmio_base + CAP1); | |
104 | } else { | |
105 | /* | |
106 | * Update shadow registers to configure period and | |
107 | * compare values. This helps current PWM period to | |
108 | * complete on reconfiguring | |
109 | */ | |
110 | writel(duty_cycles, pc->mmio_base + CAP4); | |
111 | writel(period_cycles, pc->mmio_base + CAP3); | |
112 | } | |
113 | ||
c06fad9d PA |
114 | if (!test_bit(PWMF_ENABLED, &pwm->flags)) { |
115 | reg_val = readw(pc->mmio_base + ECCTL2); | |
116 | /* Disable APWM mode to put APWM output Low */ | |
117 | reg_val &= ~ECCTL2_APWM_MODE; | |
118 | writew(reg_val, pc->mmio_base + ECCTL2); | |
119 | } | |
120 | ||
8e0cb05b PA |
121 | pm_runtime_put_sync(pc->chip.dev); |
122 | return 0; | |
123 | } | |
124 | ||
454870a4 PA |
125 | static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, |
126 | enum pwm_polarity polarity) | |
127 | { | |
128 | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | |
129 | unsigned short reg_val; | |
130 | ||
131 | pm_runtime_get_sync(pc->chip.dev); | |
132 | reg_val = readw(pc->mmio_base + ECCTL2); | |
133 | if (polarity == PWM_POLARITY_INVERSED) | |
134 | /* Duty cycle defines LOW period of PWM */ | |
135 | reg_val |= ECCTL2_APWM_POL_LOW; | |
136 | else | |
137 | /* Duty cycle defines HIGH period of PWM */ | |
138 | reg_val &= ~ECCTL2_APWM_POL_LOW; | |
139 | ||
140 | writew(reg_val, pc->mmio_base + ECCTL2); | |
141 | pm_runtime_put_sync(pc->chip.dev); | |
142 | return 0; | |
143 | } | |
144 | ||
8e0cb05b PA |
145 | static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
146 | { | |
147 | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | |
148 | unsigned int reg_val; | |
149 | ||
150 | /* Leave clock enabled on enabling PWM */ | |
151 | pm_runtime_get_sync(pc->chip.dev); | |
152 | ||
153 | /* | |
154 | * Enable 'Free run Time stamp counter mode' to start counter | |
155 | * and 'APWM mode' to enable APWM output | |
156 | */ | |
157 | reg_val = readw(pc->mmio_base + ECCTL2); | |
158 | reg_val |= ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE; | |
159 | writew(reg_val, pc->mmio_base + ECCTL2); | |
160 | return 0; | |
161 | } | |
162 | ||
163 | static void ecap_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) | |
164 | { | |
165 | struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip); | |
166 | unsigned int reg_val; | |
167 | ||
168 | /* | |
169 | * Disable 'Free run Time stamp counter mode' to stop counter | |
170 | * and 'APWM mode' to put APWM output to low | |
171 | */ | |
172 | reg_val = readw(pc->mmio_base + ECCTL2); | |
173 | reg_val &= ~(ECCTL2_TSCTR_FREERUN | ECCTL2_APWM_MODE); | |
174 | writew(reg_val, pc->mmio_base + ECCTL2); | |
175 | ||
176 | /* Disable clock on PWM disable */ | |
177 | pm_runtime_put_sync(pc->chip.dev); | |
178 | } | |
179 | ||
180 | static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) | |
181 | { | |
182 | if (test_bit(PWMF_ENABLED, &pwm->flags)) { | |
183 | dev_warn(chip->dev, "Removing PWM device without disabling\n"); | |
184 | pm_runtime_put_sync(chip->dev); | |
185 | } | |
186 | } | |
187 | ||
188 | static const struct pwm_ops ecap_pwm_ops = { | |
189 | .free = ecap_pwm_free, | |
190 | .config = ecap_pwm_config, | |
454870a4 | 191 | .set_polarity = ecap_pwm_set_polarity, |
8e0cb05b PA |
192 | .enable = ecap_pwm_enable, |
193 | .disable = ecap_pwm_disable, | |
194 | .owner = THIS_MODULE, | |
195 | }; | |
196 | ||
333b08ee PA |
197 | static const struct of_device_id ecap_of_match[] = { |
198 | { .compatible = "ti,am33xx-ecap" }, | |
199 | {}, | |
200 | }; | |
201 | MODULE_DEVICE_TABLE(of, ecap_of_match); | |
202 | ||
3e9fe83d | 203 | static int ecap_pwm_probe(struct platform_device *pdev) |
8e0cb05b PA |
204 | { |
205 | int ret; | |
206 | struct resource *r; | |
207 | struct clk *clk; | |
208 | struct ecap_pwm_chip *pc; | |
333b08ee | 209 | u16 status; |
8e0cb05b PA |
210 | |
211 | pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); | |
c10d5063 | 212 | if (!pc) |
8e0cb05b | 213 | return -ENOMEM; |
8e0cb05b PA |
214 | |
215 | clk = devm_clk_get(&pdev->dev, "fck"); | |
216 | if (IS_ERR(clk)) { | |
217 | dev_err(&pdev->dev, "failed to get clock\n"); | |
218 | return PTR_ERR(clk); | |
219 | } | |
220 | ||
221 | pc->clk_rate = clk_get_rate(clk); | |
222 | if (!pc->clk_rate) { | |
223 | dev_err(&pdev->dev, "failed to get clock rate\n"); | |
224 | return -EINVAL; | |
225 | } | |
226 | ||
227 | pc->chip.dev = &pdev->dev; | |
228 | pc->chip.ops = &ecap_pwm_ops; | |
333b08ee PA |
229 | pc->chip.of_xlate = of_pwm_xlate_with_flags; |
230 | pc->chip.of_pwm_n_cells = 3; | |
8e0cb05b PA |
231 | pc->chip.base = -1; |
232 | pc->chip.npwm = 1; | |
233 | ||
234 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
6d4294d1 TR |
235 | pc->mmio_base = devm_ioremap_resource(&pdev->dev, r); |
236 | if (IS_ERR(pc->mmio_base)) | |
237 | return PTR_ERR(pc->mmio_base); | |
8e0cb05b PA |
238 | |
239 | ret = pwmchip_add(&pc->chip); | |
240 | if (ret < 0) { | |
241 | dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); | |
242 | return ret; | |
243 | } | |
244 | ||
245 | pm_runtime_enable(&pdev->dev); | |
333b08ee PA |
246 | pm_runtime_get_sync(&pdev->dev); |
247 | ||
248 | status = pwmss_submodule_state_change(pdev->dev.parent, | |
249 | PWMSS_ECAPCLK_EN); | |
250 | if (!(status & PWMSS_ECAPCLK_EN_ACK)) { | |
251 | dev_err(&pdev->dev, "PWMSS config space clock enable failed\n"); | |
252 | ret = -EINVAL; | |
253 | goto pwmss_clk_failure; | |
254 | } | |
255 | ||
256 | pm_runtime_put_sync(&pdev->dev); | |
257 | ||
8e0cb05b PA |
258 | platform_set_drvdata(pdev, pc); |
259 | return 0; | |
333b08ee PA |
260 | |
261 | pwmss_clk_failure: | |
262 | pm_runtime_put_sync(&pdev->dev); | |
263 | pm_runtime_disable(&pdev->dev); | |
264 | pwmchip_remove(&pc->chip); | |
265 | return ret; | |
8e0cb05b PA |
266 | } |
267 | ||
77f37917 | 268 | static int ecap_pwm_remove(struct platform_device *pdev) |
8e0cb05b PA |
269 | { |
270 | struct ecap_pwm_chip *pc = platform_get_drvdata(pdev); | |
271 | ||
333b08ee PA |
272 | pm_runtime_get_sync(&pdev->dev); |
273 | /* | |
274 | * Due to hardware misbehaviour, acknowledge of the stop_req | |
275 | * is missing. Hence checking of the status bit skipped. | |
276 | */ | |
277 | pwmss_submodule_state_change(pdev->dev.parent, PWMSS_ECAPCLK_STOP_REQ); | |
278 | pm_runtime_put_sync(&pdev->dev); | |
279 | ||
8e0cb05b PA |
280 | pm_runtime_disable(&pdev->dev); |
281 | return pwmchip_remove(&pc->chip); | |
282 | } | |
283 | ||
3943a650 | 284 | #ifdef CONFIG_PM_SLEEP |
a38c9898 | 285 | static void ecap_pwm_save_context(struct ecap_pwm_chip *pc) |
0d75c203 PA |
286 | { |
287 | pm_runtime_get_sync(pc->chip.dev); | |
288 | pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2); | |
289 | pc->ctx.cap4 = readl(pc->mmio_base + CAP4); | |
290 | pc->ctx.cap3 = readl(pc->mmio_base + CAP3); | |
291 | pm_runtime_put_sync(pc->chip.dev); | |
292 | } | |
293 | ||
a38c9898 | 294 | static void ecap_pwm_restore_context(struct ecap_pwm_chip *pc) |
0d75c203 PA |
295 | { |
296 | writel(pc->ctx.cap3, pc->mmio_base + CAP3); | |
297 | writel(pc->ctx.cap4, pc->mmio_base + CAP4); | |
298 | writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2); | |
299 | } | |
300 | ||
301 | static int ecap_pwm_suspend(struct device *dev) | |
302 | { | |
303 | struct ecap_pwm_chip *pc = dev_get_drvdata(dev); | |
304 | struct pwm_device *pwm = pc->chip.pwms; | |
305 | ||
306 | ecap_pwm_save_context(pc); | |
307 | ||
308 | /* Disable explicitly if PWM is running */ | |
309 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
310 | pm_runtime_put_sync(dev); | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
315 | static int ecap_pwm_resume(struct device *dev) | |
316 | { | |
317 | struct ecap_pwm_chip *pc = dev_get_drvdata(dev); | |
318 | struct pwm_device *pwm = pc->chip.pwms; | |
319 | ||
320 | /* Enable explicitly if PWM was running */ | |
321 | if (test_bit(PWMF_ENABLED, &pwm->flags)) | |
322 | pm_runtime_get_sync(dev); | |
323 | ||
324 | ecap_pwm_restore_context(pc); | |
325 | return 0; | |
326 | } | |
b78f5fc9 | 327 | #endif |
0d75c203 PA |
328 | |
329 | static SIMPLE_DEV_PM_OPS(ecap_pwm_pm_ops, ecap_pwm_suspend, ecap_pwm_resume); | |
330 | ||
8e0cb05b PA |
331 | static struct platform_driver ecap_pwm_driver = { |
332 | .driver = { | |
333b08ee | 333 | .name = "ecap", |
333b08ee | 334 | .of_match_table = ecap_of_match, |
0d75c203 | 335 | .pm = &ecap_pwm_pm_ops, |
8e0cb05b PA |
336 | }, |
337 | .probe = ecap_pwm_probe, | |
fd109112 | 338 | .remove = ecap_pwm_remove, |
8e0cb05b PA |
339 | }; |
340 | ||
341 | module_platform_driver(ecap_pwm_driver); | |
342 | ||
343 | MODULE_DESCRIPTION("ECAP PWM driver"); | |
344 | MODULE_AUTHOR("Texas Instruments"); | |
345 | MODULE_LICENSE("GPL"); |