Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 009e56f67de239779e3710bffc1b430257441ea3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/*
 * Remote processor machine-specific module for DA8XX
 *
 * Copyright (C) 2013 Texas Instruments, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>

#include <mach/clock.h>   /* for davinci_clk_reset_assert/deassert() */

#include "remoteproc_internal.h"

static char *da8xx_fw_name;
module_param(da8xx_fw_name, charp, S_IRUGO);
MODULE_PARM_DESC(da8xx_fw_name,
		 "Name of DSP firmware file in /lib/firmware (if not specified defaults to 'rproc-dsp-fw')");

/*
 * OMAP-L138 Technical References:
 * http://www.ti.com/product/omap-l138
 */
#define SYSCFG_CHIPSIG0 BIT(0)
#define SYSCFG_CHIPSIG1 BIT(1)
#define SYSCFG_CHIPSIG2 BIT(2)
#define SYSCFG_CHIPSIG3 BIT(3)
#define SYSCFG_CHIPSIG4 BIT(4)

/**
 * struct da8xx_rproc - da8xx remote processor instance state
 * @rproc: rproc handle
 * @dsp_clk: placeholder for platform's DSP clk
 * @ack_fxn: chip-specific ack function for ack'ing irq
 * @irq_data: ack_fxn function parameter
 * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
 * @bootreg: virt ptr to DSP boot address register (HOST1CFG)
 * @irq: irq # used by this instance
 */
struct da8xx_rproc {
	struct rproc *rproc;
	struct clk *dsp_clk;
	void (*ack_fxn)(struct irq_data *data);
	struct irq_data *irq_data;
	void __iomem *chipsig;
	void __iomem *bootreg;
	int irq;
};

/**
 * handle_event() - inbound virtqueue message workqueue function
 *
 * This function is registered as a kernel thread and is scheduled by the
 * kernel handler.
 */
static irqreturn_t handle_event(int irq, void *p)
{
	struct rproc *rproc = (struct rproc *)p;

	/* Process incoming buffers on all our vrings */
	rproc_vq_interrupt(rproc, 0);
	rproc_vq_interrupt(rproc, 1);

	return IRQ_HANDLED;
}

/**
 * da8xx_rproc_callback() - inbound virtqueue message handler
 *
 * This handler is invoked directly by the kernel whenever the remote
 * core (DSP) has modified the state of a virtqueue.  There is no
 * "payload" message indicating the virtqueue index as is the case with
 * mailbox-based implementations on OMAP4.  As such, this handler "polls"
 * each known virtqueue index for every invocation.
 */
static irqreturn_t da8xx_rproc_callback(int irq, void *p)
{
	struct rproc *rproc = (struct rproc *)p;
	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
	u32 chipsig;

	chipsig = readl(drproc->chipsig);
	if (chipsig & SYSCFG_CHIPSIG0) {
		/* Clear interrupt level source */
		writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4);

		/*
		 * ACK intr to AINTC.
		 *
		 * It has already been ack'ed by the kernel before calling
		 * this function, but since the ARM<->DSP interrupts in the
		 * CHIPSIG register are "level" instead of "pulse" variety,
		 * we need to ack it after taking down the level else we'll
		 * be called again immediately after returning.
		 */
		drproc->ack_fxn(drproc->irq_data);

		return IRQ_WAKE_THREAD;
	}

	return IRQ_HANDLED;
}

static int da8xx_rproc_start(struct rproc *rproc)
{
	struct device *dev = rproc->dev.parent;
	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
	struct clk *dsp_clk = drproc->dsp_clk;

	/* hw requires the start (boot) address be on 1KB boundary */
	if (rproc->bootaddr & 0x3ff) {
		dev_err(dev, "invalid boot address: must be aligned to 1KB\n");

		return -EINVAL;
	}

	writel(rproc->bootaddr, drproc->bootreg);

	clk_enable(dsp_clk);
	davinci_clk_reset_deassert(dsp_clk);

	return 0;
}

static int da8xx_rproc_stop(struct rproc *rproc)
{
	struct da8xx_rproc *drproc = rproc->priv;

	clk_disable(drproc->dsp_clk);

	return 0;
}

/* kick a virtqueue */
static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
{
	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;

	/* Interupt remote proc */
	writel(SYSCFG_CHIPSIG2, drproc->chipsig);
}

static struct rproc_ops da8xx_rproc_ops = {
	.start = da8xx_rproc_start,
	.stop = da8xx_rproc_stop,
	.kick = da8xx_rproc_kick,
};

static int reset_assert(struct device *dev)
{
	struct clk *dsp_clk;

	dsp_clk = clk_get(dev, NULL);
	if (IS_ERR(dsp_clk)) {
		dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
		return PTR_ERR(dsp_clk);
	}

	davinci_clk_reset_assert(dsp_clk);
	clk_put(dsp_clk);

	return 0;
}

static int da8xx_rproc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct da8xx_rproc *drproc;
	struct rproc *rproc;
	struct irq_data *irq_data;
	struct resource *bootreg_res;
	struct resource *chipsig_res;
	struct clk *dsp_clk;
	void __iomem *chipsig;
	void __iomem *bootreg;
	int irq;
	int ret;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
		return irq;
	}

	irq_data = irq_get_irq_data(irq);
	if (!irq_data) {
		dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
		return -EINVAL;
	}

	bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	bootreg = devm_ioremap_resource(dev, bootreg_res);
	if (IS_ERR(bootreg))
		return PTR_ERR(bootreg);

	chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	chipsig = devm_ioremap_resource(dev, chipsig_res);
	if (IS_ERR(chipsig))
		return PTR_ERR(chipsig);

	dsp_clk = devm_clk_get(dev, NULL);
	if (IS_ERR(dsp_clk)) {
		dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));

		return PTR_ERR(dsp_clk);
	}

	rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
		sizeof(*drproc));
	if (!rproc)
		return -ENOMEM;

	drproc = rproc->priv;
	drproc->rproc = rproc;
	rproc->has_iommu = false;

	platform_set_drvdata(pdev, rproc);

	/* everything the ISR needs is now setup, so hook it up */
	ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
					handle_event, 0, "da8xx-remoteproc",
					rproc);
	if (ret) {
		dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
		goto free_rproc;
	}

	/*
	 * rproc_add() can end up enabling the DSP's clk with the DSP
	 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
	 * held in reset at the time it is called.
	 */
	ret = reset_assert(dev);
	if (ret)
		goto free_rproc;

	drproc->chipsig = chipsig;
	drproc->bootreg = bootreg;
	drproc->ack_fxn = irq_data->chip->irq_ack;
	drproc->irq_data = irq_data;
	drproc->irq = irq;
	drproc->dsp_clk = dsp_clk;

	ret = rproc_add(rproc);
	if (ret) {
		dev_err(dev, "rproc_add failed: %d\n", ret);
		goto free_rproc;
	}

	return 0;

free_rproc:
	rproc_put(rproc);

	return ret;
}

static int da8xx_rproc_remove(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct rproc *rproc = platform_get_drvdata(pdev);
	struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;

	/*
	 * It's important to place the DSP in reset before going away,
	 * since a subsequent insmod of this module may enable the DSP's
	 * clock before its program/boot-address has been loaded and
	 * before this module's probe has had a chance to reset the DSP.
	 * Without the reset, the DSP can lockup permanently when it
	 * begins executing garbage.
	 */
	reset_assert(dev);

	/*
	 * The devm subsystem might end up releasing things before
	 * freeing the irq, thus allowing an interrupt to sneak in while
	 * the device is being removed.  This should prevent that.
	 */
	disable_irq(drproc->irq);

	rproc_del(rproc);
	rproc_put(rproc);

	return 0;
}

static struct platform_driver da8xx_rproc_driver = {
	.probe = da8xx_rproc_probe,
	.remove = da8xx_rproc_remove,
	.driver = {
		.name = "davinci-rproc",
	},
};

module_platform_driver(da8xx_rproc_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DA8XX Remote Processor control driver");