1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Support for the camera device found on Marvell MMP processors; known
4 * to work with the Armada 610 as used in the OLPC 1.75 system.
5 *
6 * Copyright 2011 Jonathan Corbet <corbet@lwn.net>
7 * Copyright 2018 Lubomir Rintel <lkundrak@v3.sk>
8 */
9
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/spinlock.h>
15 #include <linux/slab.h>
16 #include <linux/videodev2.h>
17 #include <media/v4l2-device.h>
18 #include <linux/platform_data/media/mmp-camera.h>
19 #include <linux/device.h>
20 #include <linux/of.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/io.h>
24 #include <linux/list.h>
25 #include <linux/pm.h>
26 #include <linux/clk.h>
27
28 #include "mcam-core.h"
29
30 MODULE_ALIAS("platform:mmp-camera");
31 MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
32 MODULE_LICENSE("GPL");
33
34 static char *mcam_clks[] = {"axi", "func", "phy"};
35
36 struct mmp_camera {
37 struct platform_device *pdev;
38 struct mcam_camera mcam;
39 struct list_head devlist;
40 struct clk *mipi_clk;
41 int irq;
42 };
43
mcam_to_cam(struct mcam_camera * mcam)44 static inline struct mmp_camera *mcam_to_cam(struct mcam_camera *mcam)
45 {
46 return container_of(mcam, struct mmp_camera, mcam);
47 }
48
49 /*
50 * A silly little infrastructure so we can keep track of our devices.
51 * Chances are that we will never have more than one of them, but
52 * the Armada 610 *does* have two controllers...
53 */
54
55 static LIST_HEAD(mmpcam_devices);
56 static struct mutex mmpcam_devices_lock;
57
mmpcam_add_device(struct mmp_camera * cam)58 static void mmpcam_add_device(struct mmp_camera *cam)
59 {
60 mutex_lock(&mmpcam_devices_lock);
61 list_add(&cam->devlist, &mmpcam_devices);
62 mutex_unlock(&mmpcam_devices_lock);
63 }
64
mmpcam_remove_device(struct mmp_camera * cam)65 static void mmpcam_remove_device(struct mmp_camera *cam)
66 {
67 mutex_lock(&mmpcam_devices_lock);
68 list_del(&cam->devlist);
69 mutex_unlock(&mmpcam_devices_lock);
70 }
71
72 /*
73 * Platform dev remove passes us a platform_device, and there's
74 * no handy unused drvdata to stash a backpointer in. So just
75 * dig it out of our list.
76 */
mmpcam_find_device(struct platform_device * pdev)77 static struct mmp_camera *mmpcam_find_device(struct platform_device *pdev)
78 {
79 struct mmp_camera *cam;
80
81 mutex_lock(&mmpcam_devices_lock);
82 list_for_each_entry(cam, &mmpcam_devices, devlist) {
83 if (cam->pdev == pdev) {
84 mutex_unlock(&mmpcam_devices_lock);
85 return cam;
86 }
87 }
88 mutex_unlock(&mmpcam_devices_lock);
89 return NULL;
90 }
91
92 /*
93 * calc the dphy register values
94 * There are three dphy registers being used.
95 * dphy[0] - CSI2_DPHY3
96 * dphy[1] - CSI2_DPHY5
97 * dphy[2] - CSI2_DPHY6
98 * CSI2_DPHY3 and CSI2_DPHY6 can be set with a default value
99 * or be calculated dynamically
100 */
mmpcam_calc_dphy(struct mcam_camera * mcam)101 static void mmpcam_calc_dphy(struct mcam_camera *mcam)
102 {
103 struct mmp_camera *cam = mcam_to_cam(mcam);
104 struct mmp_camera_platform_data *pdata = cam->pdev->dev.platform_data;
105 struct device *dev = &cam->pdev->dev;
106 unsigned long tx_clk_esc;
107
108 /*
109 * If CSI2_DPHY3 is calculated dynamically,
110 * pdata->lane_clk should be already set
111 * either in the board driver statically
112 * or in the sensor driver dynamically.
113 */
114 /*
115 * dphy[0] - CSI2_DPHY3:
116 * bit 0 ~ bit 7: HS Term Enable.
117 * defines the time that the DPHY
118 * wait before enabling the data
119 * lane termination after detecting
120 * that the sensor has driven the data
121 * lanes to the LP00 bridge state.
122 * The value is calculated by:
123 * (Max T(D_TERM_EN)/Period(DDR)) - 1
124 * bit 8 ~ bit 15: HS_SETTLE
125 * Time interval during which the HS
126 * receiver shall ignore any Data Lane
127 * HS transitions.
128 * The value has been calibrated on
129 * different boards. It seems to work well.
130 *
131 * More detail please refer
132 * MIPI Alliance Spectification for D-PHY
133 * document for explanation of HS-SETTLE
134 * and D-TERM-EN.
135 */
136 switch (pdata->dphy3_algo) {
137 case DPHY3_ALGO_PXA910:
138 /*
139 * Calculate CSI2_DPHY3 algo for PXA910
140 */
141 pdata->dphy[0] =
142 (((1 + (pdata->lane_clk * 80) / 1000) & 0xff) << 8)
143 | (1 + pdata->lane_clk * 35 / 1000);
144 break;
145 case DPHY3_ALGO_PXA2128:
146 /*
147 * Calculate CSI2_DPHY3 algo for PXA2128
148 */
149 pdata->dphy[0] =
150 (((2 + (pdata->lane_clk * 110) / 1000) & 0xff) << 8)
151 | (1 + pdata->lane_clk * 35 / 1000);
152 break;
153 default:
154 /*
155 * Use default CSI2_DPHY3 value for PXA688/PXA988
156 */
157 dev_dbg(dev, "camera: use the default CSI2_DPHY3 value\n");
158 }
159
160 /*
161 * mipi_clk will never be changed, it is a fixed value on MMP
162 */
163 if (IS_ERR(cam->mipi_clk))
164 return;
165
166 /* get the escape clk, this is hard coded */
167 clk_prepare_enable(cam->mipi_clk);
168 tx_clk_esc = (clk_get_rate(cam->mipi_clk) / 1000000) / 12;
169 clk_disable_unprepare(cam->mipi_clk);
170 /*
171 * dphy[2] - CSI2_DPHY6:
172 * bit 0 ~ bit 7: CK Term Enable
173 * Time for the Clock Lane receiver to enable the HS line
174 * termination. The value is calculated similarly with
175 * HS Term Enable
176 * bit 8 ~ bit 15: CK Settle
177 * Time interval during which the HS receiver shall ignore
178 * any Clock Lane HS transitions.
179 * The value is calibrated on the boards.
180 */
181 pdata->dphy[2] =
182 ((((534 * tx_clk_esc) / 2000 - 1) & 0xff) << 8)
183 | (((38 * tx_clk_esc) / 1000 - 1) & 0xff);
184
185 dev_dbg(dev, "camera: DPHY sets: dphy3=0x%x, dphy5=0x%x, dphy6=0x%x\n",
186 pdata->dphy[0], pdata->dphy[1], pdata->dphy[2]);
187 }
188
mmpcam_irq(int irq,void * data)189 static irqreturn_t mmpcam_irq(int irq, void *data)
190 {
191 struct mcam_camera *mcam = data;
192 unsigned int irqs, handled;
193
194 spin_lock(&mcam->dev_lock);
195 irqs = mcam_reg_read(mcam, REG_IRQSTAT);
196 handled = mccic_irq(mcam, irqs);
197 spin_unlock(&mcam->dev_lock);
198 return IRQ_RETVAL(handled);
199 }
200
mcam_init_clk(struct mcam_camera * mcam)201 static void mcam_init_clk(struct mcam_camera *mcam)
202 {
203 unsigned int i;
204
205 for (i = 0; i < NR_MCAM_CLK; i++) {
206 if (mcam_clks[i] != NULL) {
207 /* Some clks are not necessary on some boards
208 * We still try to run even it fails getting clk
209 */
210 mcam->clk[i] = devm_clk_get(mcam->dev, mcam_clks[i]);
211 if (IS_ERR(mcam->clk[i]))
212 dev_warn(mcam->dev, "Could not get clk: %s\n",
213 mcam_clks[i]);
214 }
215 }
216 }
217
mmpcam_probe(struct platform_device * pdev)218 static int mmpcam_probe(struct platform_device *pdev)
219 {
220 struct mmp_camera *cam;
221 struct mcam_camera *mcam;
222 struct resource *res;
223 struct fwnode_handle *ep;
224 struct mmp_camera_platform_data *pdata;
225 int ret;
226
227 cam = devm_kzalloc(&pdev->dev, sizeof(*cam), GFP_KERNEL);
228 if (cam == NULL)
229 return -ENOMEM;
230 cam->pdev = pdev;
231 INIT_LIST_HEAD(&cam->devlist);
232
233 mcam = &cam->mcam;
234 mcam->calc_dphy = mmpcam_calc_dphy;
235 mcam->dev = &pdev->dev;
236 pdata = pdev->dev.platform_data;
237 if (pdata) {
238 mcam->mclk_src = pdata->mclk_src;
239 mcam->mclk_div = pdata->mclk_div;
240 mcam->bus_type = pdata->bus_type;
241 mcam->dphy = pdata->dphy;
242 mcam->lane = pdata->lane;
243 } else {
244 /*
245 * These are values that used to be hardcoded in mcam-core and
246 * work well on a OLPC XO 1.75 with a parallel bus sensor.
247 * If it turns out other setups make sense, the values should
248 * be obtained from the device tree.
249 */
250 mcam->mclk_src = 3;
251 mcam->mclk_div = 2;
252 }
253 if (mcam->bus_type == V4L2_MBUS_CSI2_DPHY) {
254 cam->mipi_clk = devm_clk_get(mcam->dev, "mipi");
255 if ((IS_ERR(cam->mipi_clk) && mcam->dphy[2] == 0))
256 return PTR_ERR(cam->mipi_clk);
257 }
258 mcam->mipi_enabled = false;
259 mcam->chip_id = MCAM_ARMADA610;
260 mcam->buffer_mode = B_DMA_sg;
261 strscpy(mcam->bus_info, "platform:mmp-camera", sizeof(mcam->bus_info));
262 spin_lock_init(&mcam->dev_lock);
263 /*
264 * Get our I/O memory.
265 */
266 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
267 mcam->regs = devm_ioremap_resource(&pdev->dev, res);
268 if (IS_ERR(mcam->regs))
269 return PTR_ERR(mcam->regs);
270 mcam->regs_size = resource_size(res);
271
272 mcam_init_clk(mcam);
273
274 /*
275 * Create a match of the sensor against its OF node.
276 */
277 ep = fwnode_graph_get_next_endpoint(of_fwnode_handle(pdev->dev.of_node),
278 NULL);
279 if (!ep)
280 return -ENODEV;
281
282 mcam->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
283 mcam->asd.match.fwnode = fwnode_graph_get_remote_port_parent(ep);
284
285 fwnode_handle_put(ep);
286
287 /*
288 * Register the device with the core.
289 */
290 ret = mccic_register(mcam);
291 if (ret)
292 return ret;
293
294 /*
295 * Add OF clock provider.
296 */
297 ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get,
298 mcam->mclk);
299 if (ret) {
300 dev_err(&pdev->dev, "can't add DT clock provider\n");
301 goto out;
302 }
303
304 /*
305 * Finally, set up our IRQ now that the core is ready to
306 * deal with it.
307 */
308 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
309 if (res == NULL) {
310 ret = -ENODEV;
311 goto out;
312 }
313 cam->irq = res->start;
314 ret = devm_request_irq(&pdev->dev, cam->irq, mmpcam_irq, IRQF_SHARED,
315 "mmp-camera", mcam);
316 if (ret == 0) {
317 mmpcam_add_device(cam);
318 return 0;
319 }
320
321 out:
322 fwnode_handle_put(mcam->asd.match.fwnode);
323 mccic_shutdown(mcam);
324
325 return ret;
326 }
327
328
mmpcam_remove(struct mmp_camera * cam)329 static int mmpcam_remove(struct mmp_camera *cam)
330 {
331 struct mcam_camera *mcam = &cam->mcam;
332
333 mmpcam_remove_device(cam);
334 mccic_shutdown(mcam);
335 return 0;
336 }
337
mmpcam_platform_remove(struct platform_device * pdev)338 static int mmpcam_platform_remove(struct platform_device *pdev)
339 {
340 struct mmp_camera *cam = mmpcam_find_device(pdev);
341
342 if (cam == NULL)
343 return -ENODEV;
344 return mmpcam_remove(cam);
345 }
346
347 /*
348 * Suspend/resume support.
349 */
350 #ifdef CONFIG_PM
351
mmpcam_suspend(struct platform_device * pdev,pm_message_t state)352 static int mmpcam_suspend(struct platform_device *pdev, pm_message_t state)
353 {
354 struct mmp_camera *cam = mmpcam_find_device(pdev);
355
356 if (state.event != PM_EVENT_SUSPEND)
357 return 0;
358 mccic_suspend(&cam->mcam);
359 return 0;
360 }
361
mmpcam_resume(struct platform_device * pdev)362 static int mmpcam_resume(struct platform_device *pdev)
363 {
364 struct mmp_camera *cam = mmpcam_find_device(pdev);
365
366 return mccic_resume(&cam->mcam);
367 }
368
369 #endif
370
371 static const struct of_device_id mmpcam_of_match[] = {
372 { .compatible = "marvell,mmp2-ccic", },
373 {},
374 };
375 MODULE_DEVICE_TABLE(of, mmpcam_of_match);
376
377 static struct platform_driver mmpcam_driver = {
378 .probe = mmpcam_probe,
379 .remove = mmpcam_platform_remove,
380 #ifdef CONFIG_PM
381 .suspend = mmpcam_suspend,
382 .resume = mmpcam_resume,
383 #endif
384 .driver = {
385 .name = "mmp-camera",
386 .of_match_table = of_match_ptr(mmpcam_of_match),
387 }
388 };
389
390
mmpcam_init_module(void)391 static int __init mmpcam_init_module(void)
392 {
393 mutex_init(&mmpcam_devices_lock);
394 return platform_driver_register(&mmpcam_driver);
395 }
396
mmpcam_exit_module(void)397 static void __exit mmpcam_exit_module(void)
398 {
399 platform_driver_unregister(&mmpcam_driver);
400 /*
401 * platform_driver_unregister() should have emptied the list
402 */
403 if (!list_empty(&mmpcam_devices))
404 printk(KERN_ERR "mmp_camera leaving devices behind\n");
405 }
406
407 module_init(mmpcam_init_module);
408 module_exit(mmpcam_exit_module);
409