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13be5432 RT |
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/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 | ||
26 | static char *da8xx_fw_name; | |
27 | module_param(da8xx_fw_name, charp, S_IRUGO); | |
28 | MODULE_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 | */ | |
52 | struct 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 | */ | |
68 | static 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 | */ | |
88 | static 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 | ||
116 | static 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 | ||
137 | static 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 */ | |
147 | static 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 | ||
155 | static struct rproc_ops da8xx_rproc_ops = { | |
156 | .start = da8xx_rproc_start, | |
157 | .stop = da8xx_rproc_stop, | |
158 | .kick = da8xx_rproc_kick, | |
159 | }; | |
160 | ||
161 | static 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)); | |
60d676c0 | 168 | return PTR_ERR(dsp_clk); |
13be5432 RT |
169 | } |
170 | ||
171 | davinci_clk_reset_assert(dsp_clk); | |
172 | clk_put(dsp_clk); | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static 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); | |
13be5432 RT |
204 | bootreg = devm_ioremap_resource(dev, bootreg_res); |
205 | if (IS_ERR(bootreg)) | |
206 | return PTR_ERR(bootreg); | |
207 | ||
0ddc5ec1 | 208 | chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1); |
13be5432 RT |
209 | chipsig = devm_ioremap_resource(dev, chipsig_res); |
210 | if (IS_ERR(chipsig)) | |
211 | return PTR_ERR(chipsig); | |
212 | ||
213 | dsp_clk = devm_clk_get(dev, NULL); | |
214 | if (IS_ERR(dsp_clk)) { | |
215 | dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk)); | |
216 | ||
217 | return PTR_ERR(dsp_clk); | |
218 | } | |
219 | ||
220 | rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name, | |
221 | sizeof(*drproc)); | |
222 | if (!rproc) | |
223 | return -ENOMEM; | |
224 | ||
225 | drproc = rproc->priv; | |
226 | drproc->rproc = rproc; | |
227 | ||
228 | platform_set_drvdata(pdev, rproc); | |
229 | ||
230 | /* everything the ISR needs is now setup, so hook it up */ | |
231 | ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback, | |
232 | handle_event, 0, "da8xx-remoteproc", | |
233 | rproc); | |
234 | if (ret) { | |
235 | dev_err(dev, "devm_request_threaded_irq error: %d\n", ret); | |
236 | goto free_rproc; | |
237 | } | |
238 | ||
239 | /* | |
240 | * rproc_add() can end up enabling the DSP's clk with the DSP | |
241 | * *not* in reset, but da8xx_rproc_start() needs the DSP to be | |
242 | * held in reset at the time it is called. | |
243 | */ | |
244 | ret = reset_assert(dev); | |
245 | if (ret) | |
246 | goto free_rproc; | |
247 | ||
248 | drproc->chipsig = chipsig; | |
249 | drproc->bootreg = bootreg; | |
250 | drproc->ack_fxn = irq_data->chip->irq_ack; | |
251 | drproc->irq_data = irq_data; | |
252 | drproc->irq = irq; | |
253 | drproc->dsp_clk = dsp_clk; | |
254 | ||
255 | ret = rproc_add(rproc); | |
256 | if (ret) { | |
257 | dev_err(dev, "rproc_add failed: %d\n", ret); | |
258 | goto free_rproc; | |
259 | } | |
260 | ||
261 | return 0; | |
262 | ||
263 | free_rproc: | |
264 | rproc_put(rproc); | |
265 | ||
266 | return ret; | |
267 | } | |
268 | ||
269 | static int da8xx_rproc_remove(struct platform_device *pdev) | |
270 | { | |
271 | struct device *dev = &pdev->dev; | |
272 | struct rproc *rproc = platform_get_drvdata(pdev); | |
273 | struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv; | |
274 | ||
275 | /* | |
276 | * It's important to place the DSP in reset before going away, | |
277 | * since a subsequent insmod of this module may enable the DSP's | |
278 | * clock before its program/boot-address has been loaded and | |
279 | * before this module's probe has had a chance to reset the DSP. | |
280 | * Without the reset, the DSP can lockup permanently when it | |
281 | * begins executing garbage. | |
282 | */ | |
283 | reset_assert(dev); | |
284 | ||
285 | /* | |
286 | * The devm subsystem might end up releasing things before | |
287 | * freeing the irq, thus allowing an interrupt to sneak in while | |
288 | * the device is being removed. This should prevent that. | |
289 | */ | |
290 | disable_irq(drproc->irq); | |
291 | ||
13be5432 RT |
292 | rproc_del(rproc); |
293 | rproc_put(rproc); | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | static struct platform_driver da8xx_rproc_driver = { | |
299 | .probe = da8xx_rproc_probe, | |
300 | .remove = da8xx_rproc_remove, | |
301 | .driver = { | |
302 | .name = "davinci-rproc", | |
303 | .owner = THIS_MODULE, | |
304 | }, | |
305 | }; | |
306 | ||
307 | module_platform_driver(da8xx_rproc_driver); | |
308 | ||
309 | MODULE_LICENSE("GPL v2"); | |
310 | MODULE_DESCRIPTION("DA8XX Remote Processor control driver"); |