blob: 129f7b9978663b159e16c30e30e3ec590656a3f0 [file] [log] [blame]
Robert Tivy13be5432013-04-09 14:20:21 -07001/*
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/platform_device.h>
20#include <linux/remoteproc.h>
21
22#include <mach/clock.h> /* for davinci_clk_reset_assert/deassert() */
23
24#include "remoteproc_internal.h"
25
26static char *da8xx_fw_name;
27module_param(da8xx_fw_name, charp, S_IRUGO);
28MODULE_PARM_DESC(da8xx_fw_name,
29 "\n\t\tName of DSP firmware file in /lib/firmware"
30 " (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/**
43 * struct da8xx_rproc - da8xx remote processor instance state
44 * @rproc: rproc handle
45 * @dsp_clk: placeholder for platform's DSP clk
46 * @ack_fxn: chip-specific ack function for ack'ing irq
47 * @irq_data: ack_fxn function parameter
48 * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR)
49 * @bootreg: virt ptr to DSP boot address register (HOST1CFG)
50 * @irq: irq # used by this instance
51 */
52struct da8xx_rproc {
53 struct rproc *rproc;
54 struct clk *dsp_clk;
55 void (*ack_fxn)(struct irq_data *data);
56 struct irq_data *irq_data;
57 void __iomem *chipsig;
58 void __iomem *bootreg;
59 int irq;
60};
61
62/**
63 * handle_event() - inbound virtqueue message workqueue function
64 *
65 * This function is registered as a kernel thread and is scheduled by the
66 * kernel handler.
67 */
68static irqreturn_t handle_event(int irq, void *p)
69{
70 struct rproc *rproc = (struct rproc *)p;
71
72 /* Process incoming buffers on all our vrings */
73 rproc_vq_interrupt(rproc, 0);
74 rproc_vq_interrupt(rproc, 1);
75
76 return IRQ_HANDLED;
77}
78
79/**
80 * da8xx_rproc_callback() - inbound virtqueue message handler
81 *
82 * This handler is invoked directly by the kernel whenever the remote
83 * core (DSP) has modified the state of a virtqueue. There is no
84 * "payload" message indicating the virtqueue index as is the case with
85 * mailbox-based implementations on OMAP4. As such, this handler "polls"
86 * each known virtqueue index for every invocation.
87 */
88static irqreturn_t da8xx_rproc_callback(int irq, void *p)
89{
90 struct rproc *rproc = (struct rproc *)p;
91 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
92 u32 chipsig;
93
94 chipsig = readl(drproc->chipsig);
95 if (chipsig & SYSCFG_CHIPSIG0) {
96 /* Clear interrupt level source */
97 writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4);
98
99 /*
100 * ACK intr to AINTC.
101 *
102 * It has already been ack'ed by the kernel before calling
103 * this function, but since the ARM<->DSP interrupts in the
104 * CHIPSIG register are "level" instead of "pulse" variety,
105 * we need to ack it after taking down the level else we'll
106 * be called again immediately after returning.
107 */
108 drproc->ack_fxn(drproc->irq_data);
109
110 return IRQ_WAKE_THREAD;
111 }
112
113 return IRQ_HANDLED;
114}
115
116static int da8xx_rproc_start(struct rproc *rproc)
117{
118 struct device *dev = rproc->dev.parent;
119 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
120 struct clk *dsp_clk = drproc->dsp_clk;
121
122 /* hw requires the start (boot) address be on 1KB boundary */
123 if (rproc->bootaddr & 0x3ff) {
124 dev_err(dev, "invalid boot address: must be aligned to 1KB\n");
125
126 return -EINVAL;
127 }
128
129 writel(rproc->bootaddr, drproc->bootreg);
130
131 clk_enable(dsp_clk);
132 davinci_clk_reset_deassert(dsp_clk);
133
134 return 0;
135}
136
137static int da8xx_rproc_stop(struct rproc *rproc)
138{
139 struct da8xx_rproc *drproc = rproc->priv;
140
141 clk_disable(drproc->dsp_clk);
142
143 return 0;
144}
145
146/* kick a virtqueue */
147static void da8xx_rproc_kick(struct rproc *rproc, int vqid)
148{
149 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
150
151 /* Interupt remote proc */
152 writel(SYSCFG_CHIPSIG2, drproc->chipsig);
153}
154
155static struct rproc_ops da8xx_rproc_ops = {
156 .start = da8xx_rproc_start,
157 .stop = da8xx_rproc_stop,
158 .kick = da8xx_rproc_kick,
159};
160
161static int reset_assert(struct device *dev)
162{
163 struct clk *dsp_clk;
164
165 dsp_clk = clk_get(dev, NULL);
166 if (IS_ERR(dsp_clk)) {
167 dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
Rusty Russell60d676c2013-07-15 11:24:08 +0930168 return PTR_ERR(dsp_clk);
Robert Tivy13be5432013-04-09 14:20:21 -0700169 }
170
171 davinci_clk_reset_assert(dsp_clk);
172 clk_put(dsp_clk);
173
174 return 0;
175}
176
177static int da8xx_rproc_probe(struct platform_device *pdev)
178{
179 struct device *dev = &pdev->dev;
180 struct da8xx_rproc *drproc;
181 struct rproc *rproc;
182 struct irq_data *irq_data;
183 struct resource *bootreg_res;
184 struct resource *chipsig_res;
185 struct clk *dsp_clk;
186 void __iomem *chipsig;
187 void __iomem *bootreg;
188 int irq;
189 int ret;
190
191 irq = platform_get_irq(pdev, 0);
192 if (irq < 0) {
193 dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq);
194 return irq;
195 }
196
197 irq_data = irq_get_irq_data(irq);
198 if (!irq_data) {
199 dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq);
200 return -EINVAL;
201 }
202
203 bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
204 if (!bootreg_res) {
205 dev_err(dev,
206 "platform_get_resource(IORESOURCE_MEM, 0): NULL\n");
207 return -EADDRNOTAVAIL;
208 }
209
210 chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
211 if (!chipsig_res) {
212 dev_err(dev,
213 "platform_get_resource(IORESOURCE_MEM, 1): NULL\n");
214 return -EADDRNOTAVAIL;
215 }
216
217 bootreg = devm_ioremap_resource(dev, bootreg_res);
218 if (IS_ERR(bootreg))
219 return PTR_ERR(bootreg);
220
221 chipsig = devm_ioremap_resource(dev, chipsig_res);
222 if (IS_ERR(chipsig))
223 return PTR_ERR(chipsig);
224
225 dsp_clk = devm_clk_get(dev, NULL);
226 if (IS_ERR(dsp_clk)) {
227 dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk));
228
229 return PTR_ERR(dsp_clk);
230 }
231
232 rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name,
233 sizeof(*drproc));
234 if (!rproc)
235 return -ENOMEM;
236
237 drproc = rproc->priv;
238 drproc->rproc = rproc;
239
240 platform_set_drvdata(pdev, rproc);
241
242 /* everything the ISR needs is now setup, so hook it up */
243 ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback,
244 handle_event, 0, "da8xx-remoteproc",
245 rproc);
246 if (ret) {
247 dev_err(dev, "devm_request_threaded_irq error: %d\n", ret);
248 goto free_rproc;
249 }
250
251 /*
252 * rproc_add() can end up enabling the DSP's clk with the DSP
253 * *not* in reset, but da8xx_rproc_start() needs the DSP to be
254 * held in reset at the time it is called.
255 */
256 ret = reset_assert(dev);
257 if (ret)
258 goto free_rproc;
259
260 drproc->chipsig = chipsig;
261 drproc->bootreg = bootreg;
262 drproc->ack_fxn = irq_data->chip->irq_ack;
263 drproc->irq_data = irq_data;
264 drproc->irq = irq;
265 drproc->dsp_clk = dsp_clk;
266
267 ret = rproc_add(rproc);
268 if (ret) {
269 dev_err(dev, "rproc_add failed: %d\n", ret);
270 goto free_rproc;
271 }
272
273 return 0;
274
275free_rproc:
276 rproc_put(rproc);
277
278 return ret;
279}
280
281static int da8xx_rproc_remove(struct platform_device *pdev)
282{
283 struct device *dev = &pdev->dev;
284 struct rproc *rproc = platform_get_drvdata(pdev);
285 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv;
286
287 /*
288 * It's important to place the DSP in reset before going away,
289 * since a subsequent insmod of this module may enable the DSP's
290 * clock before its program/boot-address has been loaded and
291 * before this module's probe has had a chance to reset the DSP.
292 * Without the reset, the DSP can lockup permanently when it
293 * begins executing garbage.
294 */
295 reset_assert(dev);
296
297 /*
298 * The devm subsystem might end up releasing things before
299 * freeing the irq, thus allowing an interrupt to sneak in while
300 * the device is being removed. This should prevent that.
301 */
302 disable_irq(drproc->irq);
303
304 devm_clk_put(dev, drproc->dsp_clk);
305
306 rproc_del(rproc);
307 rproc_put(rproc);
308
309 return 0;
310}
311
312static struct platform_driver da8xx_rproc_driver = {
313 .probe = da8xx_rproc_probe,
314 .remove = da8xx_rproc_remove,
315 .driver = {
316 .name = "davinci-rproc",
317 .owner = THIS_MODULE,
318 },
319};
320
321module_platform_driver(da8xx_rproc_driver);
322
323MODULE_LICENSE("GPL v2");
324MODULE_DESCRIPTION("DA8XX Remote Processor control driver");