1 /*
2  * Remote processor machine-specific module for DA8XX
3  *
4  * Copyright (C) 2013 Texas Instruments, Inc.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * version 2 as published by the Free Software Foundation.
9  */
10 
11 #include <linux/bitops.h>
12 #include <linux/clk.h>
13 #include <linux/reset.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/of_reserved_mem.h>
21 #include <linux/platform_device.h>
22 #include <linux/remoteproc.h>
23 
24 #include "remoteproc_internal.h"
25 
26 static char *da8xx_fw_name;
27 module_param(da8xx_fw_name, charp, 0444);
28 MODULE_PARM_DESC(da8xx_fw_name,
29 		 "Name of DSP firmware file in /lib/firmware (if not specified defaults to 'rproc-dsp-fw')");
30 
31 /*
32  * OMAP-L138 Technical References:
33  * http://www.ti.com/product/omap-l138
34  */
35 #define SYSCFG_CHIPSIG0 BIT(0)
36 #define SYSCFG_CHIPSIG1 BIT(1)
37 #define SYSCFG_CHIPSIG2 BIT(2)
38 #define SYSCFG_CHIPSIG3 BIT(3)
39 #define SYSCFG_CHIPSIG4 BIT(4)
40 
41 #define DA8XX_RPROC_LOCAL_ADDRESS_MASK	(SZ_16M - 1)
42 
43 /**
44  * struct da8xx_rproc_mem - internal memory structure
45  * @cpu_addr: MPU virtual address of the memory region
46  * @bus_addr: Bus address used to access the memory region
47  * @dev_addr: Device address of the memory region from DSP view
48  * @size: Size of the memory region
49  */
50 struct da8xx_rproc_mem {
51 	void __iomem *cpu_addr;
52 	phys_addr_t bus_addr;
53 	u32 dev_addr;
54 	size_t size;
55 };
56 
57 /**
58  * struct da8xx_rproc - da8xx remote processor instance state
59  * @rproc: rproc handle
60  * @mem: internal memory regions data
61  * @num_mems: number of internal memory regions
62  * @dsp_clk: placeholder for platform's DSP clk
63  * @ack_fxn: chip-specific ack function for ack'ing irq
64  * @irq_data: ack_fxn function parameter
65  * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
66  * @bootreg: virt ptr to DSP boot address register (HOST1CFG)
67  * @irq: irq # used by this instance
68  */
69 struct da8xx_rproc {
70 	struct rproc *rproc;
71 	struct da8xx_rproc_mem *mem;
72 	int num_mems;
73 	struct clk *dsp_clk;
74 	struct reset_control *dsp_reset;
75 	void (*ack_fxn)(struct irq_data *data);
76 	struct irq_data *irq_data;
77 	void __iomem *chipsig;
78 	void __iomem *bootreg;
79 	int irq;
80 };
81 
82 /**
83  * handle_event() - inbound virtqueue message workqueue function
84  *
85  * This function is registered as a kernel thread and is scheduled by the
86  * kernel handler.
87  */
88 static irqreturn_t handle_event(int irq, void *p)
89 {
90 	struct rproc *rproc = (struct rproc *)p;
91 
92 	/* Process incoming buffers on all our vrings */
93 	rproc_vq_interrupt(rproc, 0);
94 	rproc_vq_interrupt(rproc, 1);
95 
96 	return IRQ_HANDLED;
97 }
98 
99 /**
100  * da8xx_rproc_callback() - inbound virtqueue message handler
101  *
102  * This handler is invoked directly by the kernel whenever the remote
103  * core (DSP) has modified the state of a virtqueue.  There is no
104  * "payload" message indicating the virtqueue index as is the case with
105  * mailbox-based implementations on OMAP4.  As such, this handler "polls"
106  * each known virtqueue index for every invocation.
107  */
108 static irqreturn_t da8xx_rproc_callback(int irq, void *p)
109 {
110 	struct rproc *rproc = (struct rproc *)p;
111 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
112 	u32 chipsig;
113 
114 	chipsig = readl(drproc->chipsig);
115 	if (chipsig & SYSCFG_CHIPSIG0) {
116 		/* Clear interrupt level source */
117 		writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4);
118 
119 		/*
120 		 * ACK intr to AINTC.
121 		 *
122 		 * It has already been ack'ed by the kernel before calling
123 		 * this function, but since the ARM<->DSP interrupts in the
124 		 * CHIPSIG register are "level" instead of "pulse" variety,
125 		 * we need to ack it after taking down the level else we'll
126 		 * be called again immediately after returning.
127 		 */
128 		drproc->ack_fxn(drproc->irq_data);
129 
130 		return IRQ_WAKE_THREAD;
131 	}
132 
133 	return IRQ_HANDLED;
134 }
135 
136 static int da8xx_rproc_start(struct rproc *rproc)
137 {
138 	struct device *dev = rproc->dev.parent;
139 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
140 	struct clk *dsp_clk = drproc->dsp_clk;
141 	struct reset_control *dsp_reset = drproc->dsp_reset;
142 	int ret;
143 
144 	/* hw requires the start (boot) address be on 1KB boundary */
145 	if (rproc->bootaddr & 0x3ff) {
146 		dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
147 
148 		return -EINVAL;
149 	}
150 
151 	writel(rproc->bootaddr, drproc->bootreg);
152 
153 	ret = clk_prepare_enable(dsp_clk);
154 	if (ret) {
155 		dev_err(dev, "clk_prepare_enable() failed: %d\n", ret);
156 		return ret;
157 	}
158 
159 	ret = reset_control_deassert(dsp_reset);
160 	if (ret) {
161 		dev_err(dev, "reset_control_deassert() failed: %d\n", ret);
162 		clk_disable_unprepare(dsp_clk);
163 		return ret;
164 	}
165 
166 	return 0;
167 }
168 
169 static int da8xx_rproc_stop(struct rproc *rproc)
170 {
171 	struct da8xx_rproc *drproc = rproc->priv;
172 	struct device *dev = rproc->dev.parent;
173 	int ret;
174 
175 	ret = reset_control_assert(drproc->dsp_reset);
176 	if (ret) {
177 		dev_err(dev, "reset_control_assert() failed: %d\n", ret);
178 		return ret;
179 	}
180 
181 	clk_disable_unprepare(drproc->dsp_clk);
182 
183 	return 0;
184 }
185 
186 /* kick a virtqueue */
187 static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
188 {
189 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
190 
191 	/* Interrupt remote proc */
192 	writel(SYSCFG_CHIPSIG2, drproc->chipsig);
193 }
194 
195 static const struct rproc_ops da8xx_rproc_ops = {
196 	.start = da8xx_rproc_start,
197 	.stop = da8xx_rproc_stop,
198 	.kick = da8xx_rproc_kick,
199 };
200 
201 static int da8xx_rproc_get_internal_memories(struct platform_device *pdev,
202 					     struct da8xx_rproc *drproc)
203 {
204 	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
205 	int num_mems = ARRAY_SIZE(mem_names);
206 	struct device *dev = &pdev->dev;
207 	struct resource *res;
208 	int i;
209 
210 	drproc->mem = devm_kcalloc(dev, num_mems, sizeof(*drproc->mem),
211 				   GFP_KERNEL);
212 	if (!drproc->mem)
213 		return -ENOMEM;
214 
215 	for (i = 0; i < num_mems; i++) {
216 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
217 						   mem_names[i]);
218 		drproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
219 		if (IS_ERR(drproc->mem[i].cpu_addr)) {
220 			dev_err(dev, "failed to parse and map %s memory\n",
221 				mem_names[i]);
222 			return PTR_ERR(drproc->mem[i].cpu_addr);
223 		}
224 		drproc->mem[i].bus_addr = res->start;
225 		drproc->mem[i].dev_addr =
226 				res->start & DA8XX_RPROC_LOCAL_ADDRESS_MASK;
227 		drproc->mem[i].size = resource_size(res);
228 
229 		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %p da 0x%x\n",
230 			mem_names[i], &drproc->mem[i].bus_addr,
231 			drproc->mem[i].size, drproc->mem[i].cpu_addr,
232 			drproc->mem[i].dev_addr);
233 	}
234 	drproc->num_mems = num_mems;
235 
236 	return 0;
237 }
238 
239 static int da8xx_rproc_probe(struct platform_device *pdev)
240 {
241 	struct device *dev = &pdev->dev;
242 	struct da8xx_rproc *drproc;
243 	struct rproc *rproc;
244 	struct irq_data *irq_data;
245 	struct resource *bootreg_res;
246 	struct resource *chipsig_res;
247 	struct clk *dsp_clk;
248 	struct reset_control *dsp_reset;
249 	void __iomem *chipsig;
250 	void __iomem *bootreg;
251 	int irq;
252 	int ret;
253 
254 	irq = platform_get_irq(pdev, 0);
255 	if (irq < 0) {
256 		dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
257 		return irq;
258 	}
259 
260 	irq_data = irq_get_irq_data(irq);
261 	if (!irq_data) {
262 		dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
263 		return -EINVAL;
264 	}
265 
266 	bootreg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
267 						   "host1cfg");
268 	bootreg = devm_ioremap_resource(dev, bootreg_res);
269 	if (IS_ERR(bootreg))
270 		return PTR_ERR(bootreg);
271 
272 	chipsig_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
273 						   "chipsig");
274 	chipsig = devm_ioremap_resource(dev, chipsig_res);
275 	if (IS_ERR(chipsig))
276 		return PTR_ERR(chipsig);
277 
278 	dsp_clk = devm_clk_get(dev, NULL);
279 	if (IS_ERR(dsp_clk)) {
280 		dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
281 
282 		return PTR_ERR(dsp_clk);
283 	}
284 
285 	dsp_reset = devm_reset_control_get_exclusive(dev, NULL);
286 	if (IS_ERR(dsp_reset)) {
287 		if (PTR_ERR(dsp_reset) != -EPROBE_DEFER)
288 			dev_err(dev, "unable to get reset control: %ld\n",
289 				PTR_ERR(dsp_reset));
290 
291 		return PTR_ERR(dsp_reset);
292 	}
293 
294 	if (dev->of_node) {
295 		ret = of_reserved_mem_device_init(dev);
296 		if (ret) {
297 			dev_err(dev, "device does not have specific CMA pool: %d\n",
298 				ret);
299 			return ret;
300 		}
301 	}
302 
303 	rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
304 		sizeof(*drproc));
305 	if (!rproc) {
306 		ret = -ENOMEM;
307 		goto free_mem;
308 	}
309 
310 	/* error recovery is not supported at present */
311 	rproc->recovery_disabled = true;
312 
313 	drproc = rproc->priv;
314 	drproc->rproc = rproc;
315 	drproc->dsp_clk = dsp_clk;
316 	drproc->dsp_reset = dsp_reset;
317 	rproc->has_iommu = false;
318 
319 	ret = da8xx_rproc_get_internal_memories(pdev, drproc);
320 	if (ret)
321 		goto free_rproc;
322 
323 	platform_set_drvdata(pdev, rproc);
324 
325 	/* everything the ISR needs is now setup, so hook it up */
326 	ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
327 					handle_event, 0, "da8xx-remoteproc",
328 					rproc);
329 	if (ret) {
330 		dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
331 		goto free_rproc;
332 	}
333 
334 	/*
335 	 * rproc_add() can end up enabling the DSP's clk with the DSP
336 	 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
337 	 * held in reset at the time it is called.
338 	 */
339 	ret = reset_control_assert(dsp_reset);
340 	if (ret)
341 		goto free_rproc;
342 
343 	drproc->chipsig = chipsig;
344 	drproc->bootreg = bootreg;
345 	drproc->ack_fxn = irq_data->chip->irq_ack;
346 	drproc->irq_data = irq_data;
347 	drproc->irq = irq;
348 
349 	ret = rproc_add(rproc);
350 	if (ret) {
351 		dev_err(dev, "rproc_add failed: %d\n", ret);
352 		goto free_rproc;
353 	}
354 
355 	return 0;
356 
357 free_rproc:
358 	rproc_free(rproc);
359 free_mem:
360 	if (dev->of_node)
361 		of_reserved_mem_device_release(dev);
362 	return ret;
363 }
364 
365 static int da8xx_rproc_remove(struct platform_device *pdev)
366 {
367 	struct rproc *rproc = platform_get_drvdata(pdev);
368 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
369 	struct device *dev = &pdev->dev;
370 
371 	/*
372 	 * The devm subsystem might end up releasing things before
373 	 * freeing the irq, thus allowing an interrupt to sneak in while
374 	 * the device is being removed.  This should prevent that.
375 	 */
376 	disable_irq(drproc->irq);
377 
378 	rproc_del(rproc);
379 	rproc_free(rproc);
380 	if (dev->of_node)
381 		of_reserved_mem_device_release(dev);
382 
383 	return 0;
384 }
385 
386 static const struct of_device_id davinci_rproc_of_match[] __maybe_unused = {
387 	{ .compatible = "ti,da850-dsp", },
388 	{ /* sentinel */ },
389 };
390 MODULE_DEVICE_TABLE(of, davinci_rproc_of_match);
391 
392 static struct platform_driver da8xx_rproc_driver = {
393 	.probe = da8xx_rproc_probe,
394 	.remove = da8xx_rproc_remove,
395 	.driver = {
396 		.name = "davinci-rproc",
397 		.of_match_table = of_match_ptr(davinci_rproc_of_match),
398 	},
399 };
400 
401 module_platform_driver(da8xx_rproc_driver);
402 
403 MODULE_LICENSE("GPL v2");
404 MODULE_DESCRIPTION("DA8XX Remote Processor control driver");
405