1 // SPDX-License-Identifier: GPL-2.0-or-later
5  * Provides a simple driver to control the ASPEED LPC snoop interface which
7  * the host to an arbitrary LPC I/O port.
27 #define DEVICE_NAME	"aspeed-lpc-snoop"
108 	return container_of(file->private_data,  in snoop_file_to_chan()
120 	if (kfifo_is_empty(&chan->fifo)) {  in snoop_file_read()
121 		if (file->f_flags & O_NONBLOCK)  in snoop_file_read()
122 			return -EAGAIN;  in snoop_file_read()
123 		ret = wait_event_interruptible(chan->wq,  in snoop_file_read()
124 				!kfifo_is_empty(&chan->fifo));  in snoop_file_read()
125 		if (ret == -ERESTARTSYS)  in snoop_file_read()
126 			return -EINTR;  in snoop_file_read()
128 	ret = kfifo_to_user(&chan->fifo, buffer, count, &copied);  in snoop_file_read()
140 	poll_wait(file, &chan->wq, pt);  in snoop_file_poll()
141 	return !kfifo_is_empty(&chan->fifo) ? EPOLLIN : 0;  in snoop_file_poll()
154 	if (!kfifo_initialized(&chan->fifo))  in put_fifo_with_discard()
156 	if (kfifo_is_full(&chan->fifo))  in put_fifo_with_discard()
157 		kfifo_skip(&chan->fifo);  in put_fifo_with_discard()
158 	kfifo_put(&chan->fifo, val);  in put_fifo_with_discard()
159 	wake_up_interruptible(&chan->wq);  in put_fifo_with_discard()
167 	if (regmap_read(lpc_snoop->regmap, HICR6, &reg))  in aspeed_lpc_snoop_irq()
170 	/* Check if one of the snoop channels is interrupting */  in aspeed_lpc_snoop_irq()
176 	regmap_write(lpc_snoop->regmap, HICR6, reg);  in aspeed_lpc_snoop_irq()
178 	/* Read and save most recent snoop'ed data byte to FIFO */  in aspeed_lpc_snoop_irq()
179 	regmap_read(lpc_snoop->regmap, SNPWDR, &data);  in aspeed_lpc_snoop_irq()
184 		put_fifo_with_discard(&lpc_snoop->chan[0], val);  in aspeed_lpc_snoop_irq()
189 		put_fifo_with_discard(&lpc_snoop->chan[1], val);  in aspeed_lpc_snoop_irq()
198 	struct device *dev = &pdev->dev;  in aspeed_lpc_snoop_config_irq()
201 	lpc_snoop->irq = platform_get_irq(pdev, 0);  in aspeed_lpc_snoop_config_irq()
202 	if (lpc_snoop->irq < 0)  in aspeed_lpc_snoop_config_irq()
203 		return -ENODEV;  in aspeed_lpc_snoop_config_irq()
205 	rc = devm_request_irq(dev, lpc_snoop->irq,  in aspeed_lpc_snoop_config_irq()
209 		dev_warn(dev, "Unable to request IRQ %d\n", lpc_snoop->irq);  in aspeed_lpc_snoop_config_irq()
210 		lpc_snoop->irq = 0;  in aspeed_lpc_snoop_config_irq()
227 	if (WARN_ON(channel->enabled))  in aspeed_lpc_enable_snoop()
228 		return -EBUSY;  in aspeed_lpc_enable_snoop()
230 	init_waitqueue_head(&channel->wq);  in aspeed_lpc_enable_snoop()
232 	channel->cfg = cfg;  in aspeed_lpc_enable_snoop()
233 	channel->miscdev.minor = MISC_DYNAMIC_MINOR;  in aspeed_lpc_enable_snoop()
234 	channel->miscdev.fops = &snoop_fops;  in aspeed_lpc_enable_snoop()
235 	channel->miscdev.parent = dev;  in aspeed_lpc_enable_snoop()
237 	channel->miscdev.name =  in aspeed_lpc_enable_snoop()
238 		devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, cfg->index);  in aspeed_lpc_enable_snoop()
239 	if (!channel->miscdev.name)  in aspeed_lpc_enable_snoop()
240 		return -ENOMEM;  in aspeed_lpc_enable_snoop()
242 	rc = kfifo_alloc(&channel->fifo, SNOOP_FIFO_SIZE, GFP_KERNEL);  in aspeed_lpc_enable_snoop()
246 	rc = misc_register(&channel->miscdev);  in aspeed_lpc_enable_snoop()
250 	/* Enable LPC snoop channel at requested port */  in aspeed_lpc_enable_snoop()
251 	regmap_set_bits(lpc_snoop->regmap, HICR5, cfg->hicr5_en);  in aspeed_lpc_enable_snoop()
252 	regmap_update_bits(lpc_snoop->regmap, SNPWADR, cfg->snpwadr_mask,  in aspeed_lpc_enable_snoop()
253 			   lpc_port << cfg->snpwadr_shift);  in aspeed_lpc_enable_snoop()
256 	if (model_data && model_data->has_hicrb_ensnp)  in aspeed_lpc_enable_snoop()
257 		regmap_set_bits(lpc_snoop->regmap, HICRB, cfg->hicrb_en);  in aspeed_lpc_enable_snoop()
259 	channel->enabled = true;  in aspeed_lpc_enable_snoop()
264 	kfifo_free(&channel->fifo);  in aspeed_lpc_enable_snoop()
272 	if (!channel->enabled)  in aspeed_lpc_disable_snoop()
276 	regmap_clear_bits(lpc_snoop->regmap, HICR5, channel->cfg->hicr5_en);  in aspeed_lpc_disable_snoop()
278 	channel->enabled = false;  in aspeed_lpc_disable_snoop()
280 	misc_deregister(&channel->miscdev);  in aspeed_lpc_disable_snoop()
281 	kfifo_free(&channel->fifo);  in aspeed_lpc_disable_snoop()
286 	struct aspeed_lpc_snoop *lpc_snoop = dev_get_drvdata(&pdev->dev);  in aspeed_lpc_snoop_remove()
288 	/* Disable both snoop channels */  in aspeed_lpc_snoop_remove()
289 	aspeed_lpc_disable_snoop(lpc_snoop, &lpc_snoop->chan[0]);  in aspeed_lpc_snoop_remove()
290 	aspeed_lpc_disable_snoop(lpc_snoop, &lpc_snoop->chan[1]);  in aspeed_lpc_snoop_remove()
301 	dev = &pdev->dev;  in aspeed_lpc_snoop_probe()
305 		return -ENOMEM;  in aspeed_lpc_snoop_probe()
307 	np = pdev->dev.parent->of_node;  in aspeed_lpc_snoop_probe()
308 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&  in aspeed_lpc_snoop_probe()
309 	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&  in aspeed_lpc_snoop_probe()
310 	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {  in aspeed_lpc_snoop_probe()
311 		dev_err(dev, "unsupported LPC device binding\n");  in aspeed_lpc_snoop_probe()
312 		return -ENODEV;  in aspeed_lpc_snoop_probe()
315 	lpc_snoop->regmap = syscon_node_to_regmap(np);  in aspeed_lpc_snoop_probe()
316 	if (IS_ERR(lpc_snoop->regmap))  in aspeed_lpc_snoop_probe()
317 		return dev_err_probe(dev, PTR_ERR(lpc_snoop->regmap), "Couldn't get regmap\n");  in aspeed_lpc_snoop_probe()
319 	dev_set_drvdata(&pdev->dev, lpc_snoop);  in aspeed_lpc_snoop_probe()
321 	lpc_snoop->clk = devm_clk_get_enabled(dev, NULL);  in aspeed_lpc_snoop_probe()
322 	if (IS_ERR(lpc_snoop->clk))  in aspeed_lpc_snoop_probe()
323 		return dev_err_probe(dev, PTR_ERR(lpc_snoop->clk), "couldn't get clock");  in aspeed_lpc_snoop_probe()
329 	static_assert(ARRAY_SIZE(channel_cfgs) == ARRAY_SIZE(lpc_snoop->chan),  in aspeed_lpc_snoop_probe()
334 		rc = of_property_read_u32_index(dev->of_node, "snoop-ports", idx, &port);  in aspeed_lpc_snoop_probe()
338 		rc = aspeed_lpc_enable_snoop(dev, lpc_snoop, &lpc_snoop->chan[idx],  in aspeed_lpc_snoop_probe()
344 	return idx == ASPEED_LPC_SNOOP_INDEX_0 ? -ENODEV : 0;  in aspeed_lpc_snoop_probe()
361 	{ .compatible = "aspeed,ast2400-lpc-snoop",
363 	{ .compatible = "aspeed,ast2500-lpc-snoop",
365 	{ .compatible = "aspeed,ast2600-lpc-snoop",
384 MODULE_DESCRIPTION("Linux driver to control Aspeed LPC snoop functionality");