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/err.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/irq.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of_reserved_mem.h>
20 #include <linux/platform_device.h>
21 #include <linux/remoteproc.h>
22 
23 #include <mach/clock.h>   /* for davinci_clk_reset_assert/deassert() */
24 
25 #include "remoteproc_internal.h"
26 
27 static char *da8xx_fw_name;
28 module_param(da8xx_fw_name, charp, S_IRUGO);
29 MODULE_PARM_DESC(da8xx_fw_name,
30 		 "Name of DSP firmware file in /lib/firmware (if not specified defaults to 'rproc-dsp-fw')");
31 
32 /*
33  * OMAP-L138 Technical References:
34  * http://www.ti.com/product/omap-l138
35  */
36 #define SYSCFG_CHIPSIG0 BIT(0)
37 #define SYSCFG_CHIPSIG1 BIT(1)
38 #define SYSCFG_CHIPSIG2 BIT(2)
39 #define SYSCFG_CHIPSIG3 BIT(3)
40 #define SYSCFG_CHIPSIG4 BIT(4)
41 
42 #define DA8XX_RPROC_LOCAL_ADDRESS_MASK	(SZ_16M - 1)
43 
44 /**
45  * struct da8xx_rproc_mem - internal memory structure
46  * @cpu_addr: MPU virtual address of the memory region
47  * @bus_addr: Bus address used to access the memory region
48  * @dev_addr: Device address of the memory region from DSP view
49  * @size: Size of the memory region
50  */
51 struct da8xx_rproc_mem {
52 	void __iomem *cpu_addr;
53 	phys_addr_t bus_addr;
54 	u32 dev_addr;
55 	size_t size;
56 };
57 
58 /**
59  * struct da8xx_rproc - da8xx remote processor instance state
60  * @rproc: rproc handle
61  * @mem: internal memory regions data
62  * @num_mems: number of internal memory regions
63  * @dsp_clk: placeholder for platform's DSP clk
64  * @ack_fxn: chip-specific ack function for ack'ing irq
65  * @irq_data: ack_fxn function parameter
66  * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
67  * @bootreg: virt ptr to DSP boot address register (HOST1CFG)
68  * @irq: irq # used by this instance
69  */
70 struct da8xx_rproc {
71 	struct rproc *rproc;
72 	struct da8xx_rproc_mem *mem;
73 	int num_mems;
74 	struct clk *dsp_clk;
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 
142 	/* hw requires the start (boot) address be on 1KB boundary */
143 	if (rproc->bootaddr & 0x3ff) {
144 		dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
145 
146 		return -EINVAL;
147 	}
148 
149 	writel(rproc->bootaddr, drproc->bootreg);
150 
151 	clk_enable(dsp_clk);
152 	davinci_clk_reset_deassert(dsp_clk);
153 
154 	return 0;
155 }
156 
157 static int da8xx_rproc_stop(struct rproc *rproc)
158 {
159 	struct da8xx_rproc *drproc = rproc->priv;
160 
161 	davinci_clk_reset_assert(drproc->dsp_clk);
162 	clk_disable(drproc->dsp_clk);
163 
164 	return 0;
165 }
166 
167 /* kick a virtqueue */
168 static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
169 {
170 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
171 
172 	/* Interrupt remote proc */
173 	writel(SYSCFG_CHIPSIG2, drproc->chipsig);
174 }
175 
176 static const struct rproc_ops da8xx_rproc_ops = {
177 	.start = da8xx_rproc_start,
178 	.stop = da8xx_rproc_stop,
179 	.kick = da8xx_rproc_kick,
180 };
181 
182 static int da8xx_rproc_get_internal_memories(struct platform_device *pdev,
183 					     struct da8xx_rproc *drproc)
184 {
185 	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
186 	int num_mems = ARRAY_SIZE(mem_names);
187 	struct device *dev = &pdev->dev;
188 	struct resource *res;
189 	int i;
190 
191 	drproc->mem = devm_kcalloc(dev, num_mems, sizeof(*drproc->mem),
192 				   GFP_KERNEL);
193 	if (!drproc->mem)
194 		return -ENOMEM;
195 
196 	for (i = 0; i < num_mems; i++) {
197 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
198 						   mem_names[i]);
199 		drproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
200 		if (IS_ERR(drproc->mem[i].cpu_addr)) {
201 			dev_err(dev, "failed to parse and map %s memory\n",
202 				mem_names[i]);
203 			return PTR_ERR(drproc->mem[i].cpu_addr);
204 		}
205 		drproc->mem[i].bus_addr = res->start;
206 		drproc->mem[i].dev_addr =
207 				res->start & DA8XX_RPROC_LOCAL_ADDRESS_MASK;
208 		drproc->mem[i].size = resource_size(res);
209 
210 		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%x va %p da 0x%x\n",
211 			mem_names[i], &drproc->mem[i].bus_addr,
212 			drproc->mem[i].size, drproc->mem[i].cpu_addr,
213 			drproc->mem[i].dev_addr);
214 	}
215 	drproc->num_mems = num_mems;
216 
217 	return 0;
218 }
219 
220 static int da8xx_rproc_probe(struct platform_device *pdev)
221 {
222 	struct device *dev = &pdev->dev;
223 	struct da8xx_rproc *drproc;
224 	struct rproc *rproc;
225 	struct irq_data *irq_data;
226 	struct resource *bootreg_res;
227 	struct resource *chipsig_res;
228 	struct clk *dsp_clk;
229 	void __iomem *chipsig;
230 	void __iomem *bootreg;
231 	int irq;
232 	int ret;
233 
234 	irq = platform_get_irq(pdev, 0);
235 	if (irq < 0) {
236 		dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
237 		return irq;
238 	}
239 
240 	irq_data = irq_get_irq_data(irq);
241 	if (!irq_data) {
242 		dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
243 		return -EINVAL;
244 	}
245 
246 	bootreg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
247 						   "host1cfg");
248 	bootreg = devm_ioremap_resource(dev, bootreg_res);
249 	if (IS_ERR(bootreg))
250 		return PTR_ERR(bootreg);
251 
252 	chipsig_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
253 						   "chipsig");
254 	chipsig = devm_ioremap_resource(dev, chipsig_res);
255 	if (IS_ERR(chipsig))
256 		return PTR_ERR(chipsig);
257 
258 	dsp_clk = devm_clk_get(dev, NULL);
259 	if (IS_ERR(dsp_clk)) {
260 		dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
261 
262 		return PTR_ERR(dsp_clk);
263 	}
264 
265 	if (dev->of_node) {
266 		ret = of_reserved_mem_device_init(dev);
267 		if (ret) {
268 			dev_err(dev, "device does not have specific CMA pool: %d\n",
269 				ret);
270 			return ret;
271 		}
272 	}
273 
274 	rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
275 		sizeof(*drproc));
276 	if (!rproc) {
277 		ret = -ENOMEM;
278 		goto free_mem;
279 	}
280 
281 	drproc = rproc->priv;
282 	drproc->rproc = rproc;
283 	drproc->dsp_clk = dsp_clk;
284 	rproc->has_iommu = false;
285 
286 	ret = da8xx_rproc_get_internal_memories(pdev, drproc);
287 	if (ret)
288 		goto free_rproc;
289 
290 	platform_set_drvdata(pdev, rproc);
291 
292 	/* everything the ISR needs is now setup, so hook it up */
293 	ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
294 					handle_event, 0, "da8xx-remoteproc",
295 					rproc);
296 	if (ret) {
297 		dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
298 		goto free_rproc;
299 	}
300 
301 	/*
302 	 * rproc_add() can end up enabling the DSP's clk with the DSP
303 	 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
304 	 * held in reset at the time it is called.
305 	 */
306 	ret = davinci_clk_reset_assert(drproc->dsp_clk);
307 	if (ret)
308 		goto free_rproc;
309 
310 	drproc->chipsig = chipsig;
311 	drproc->bootreg = bootreg;
312 	drproc->ack_fxn = irq_data->chip->irq_ack;
313 	drproc->irq_data = irq_data;
314 	drproc->irq = irq;
315 
316 	ret = rproc_add(rproc);
317 	if (ret) {
318 		dev_err(dev, "rproc_add failed: %d\n", ret);
319 		goto free_rproc;
320 	}
321 
322 	return 0;
323 
324 free_rproc:
325 	rproc_free(rproc);
326 free_mem:
327 	if (dev->of_node)
328 		of_reserved_mem_device_release(dev);
329 	return ret;
330 }
331 
332 static int da8xx_rproc_remove(struct platform_device *pdev)
333 {
334 	struct rproc *rproc = platform_get_drvdata(pdev);
335 	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
336 	struct device *dev = &pdev->dev;
337 
338 	/*
339 	 * The devm subsystem might end up releasing things before
340 	 * freeing the irq, thus allowing an interrupt to sneak in while
341 	 * the device is being removed.  This should prevent that.
342 	 */
343 	disable_irq(drproc->irq);
344 
345 	rproc_del(rproc);
346 	rproc_free(rproc);
347 	if (dev->of_node)
348 		of_reserved_mem_device_release(dev);
349 
350 	return 0;
351 }
352 
353 static const struct of_device_id davinci_rproc_of_match[] __maybe_unused = {
354 	{ .compatible = "ti,da850-dsp", },
355 	{ /* sentinel */ },
356 };
357 MODULE_DEVICE_TABLE(of, davinci_rproc_of_match);
358 
359 static struct platform_driver da8xx_rproc_driver = {
360 	.probe = da8xx_rproc_probe,
361 	.remove = da8xx_rproc_remove,
362 	.driver = {
363 		.name = "davinci-rproc",
364 		.of_match_table = of_match_ptr(davinci_rproc_of_match),
365 	},
366 };
367 
368 module_platform_driver(da8xx_rproc_driver);
369 
370 MODULE_LICENSE("GPL v2");
371 MODULE_DESCRIPTION("DA8XX Remote Processor control driver");
372