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.
26 #define DEVICE_NAME	"aspeed-lpc-snoop"
55 	/* The ast2400 has bits 14 and 15 as reserved, whereas the ast2500
75 	return container_of(file->private_data,  in snoop_file_to_chan()
87 	if (kfifo_is_empty(&chan->fifo)) {  in snoop_file_read()
88 		if (file->f_flags & O_NONBLOCK)  in snoop_file_read()
89 			return -EAGAIN;  in snoop_file_read()
90 		ret = wait_event_interruptible(chan->wq,  in snoop_file_read()
91 				!kfifo_is_empty(&chan->fifo));  in snoop_file_read()
92 		if (ret == -ERESTARTSYS)  in snoop_file_read()
93 			return -EINTR;  in snoop_file_read()
95 	ret = kfifo_to_user(&chan->fifo, buffer, count, &copied);  in snoop_file_read()
105 	poll_wait(file, &chan->wq, pt);  in snoop_file_poll()
106 	return !kfifo_is_empty(&chan->fifo) ? EPOLLIN : 0;  in snoop_file_poll()
119 	if (!kfifo_initialized(&chan->fifo))  in put_fifo_with_discard()
121 	if (kfifo_is_full(&chan->fifo))  in put_fifo_with_discard()
122 		kfifo_skip(&chan->fifo);  in put_fifo_with_discard()
123 	kfifo_put(&chan->fifo, val);  in put_fifo_with_discard()
124 	wake_up_interruptible(&chan->wq);  in put_fifo_with_discard()
132 	if (regmap_read(lpc_snoop->regmap, HICR6, &reg))  in aspeed_lpc_snoop_irq()
141 	regmap_write(lpc_snoop->regmap, HICR6, reg);  in aspeed_lpc_snoop_irq()
144 	regmap_read(lpc_snoop->regmap, SNPWDR, &data);  in aspeed_lpc_snoop_irq()
149 		put_fifo_with_discard(&lpc_snoop->chan[0], val);  in aspeed_lpc_snoop_irq()
154 		put_fifo_with_discard(&lpc_snoop->chan[1], val);  in aspeed_lpc_snoop_irq()
163 	struct device *dev = &pdev->dev;  in aspeed_lpc_snoop_config_irq()
166 	lpc_snoop->irq = platform_get_irq(pdev, 0);  in aspeed_lpc_snoop_config_irq()
167 	if (!lpc_snoop->irq)  in aspeed_lpc_snoop_config_irq()
168 		return -ENODEV;  in aspeed_lpc_snoop_config_irq()
170 	rc = devm_request_irq(dev, lpc_snoop->irq,  in aspeed_lpc_snoop_config_irq()
174 		dev_warn(dev, "Unable to request IRQ %d\n", lpc_snoop->irq);  in aspeed_lpc_snoop_config_irq()
175 		lpc_snoop->irq = 0;  in aspeed_lpc_snoop_config_irq()
191 	init_waitqueue_head(&lpc_snoop->chan[channel].wq);  in aspeed_lpc_enable_snoop()
193 	rc = kfifo_alloc(&lpc_snoop->chan[channel].fifo,  in aspeed_lpc_enable_snoop()
198 	lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR;  in aspeed_lpc_enable_snoop()
199 	lpc_snoop->chan[channel].miscdev.name =  in aspeed_lpc_enable_snoop()
201 	lpc_snoop->chan[channel].miscdev.fops = &snoop_fops;  in aspeed_lpc_enable_snoop()
202 	lpc_snoop->chan[channel].miscdev.parent = dev;  in aspeed_lpc_enable_snoop()
203 	rc = misc_register(&lpc_snoop->chan[channel].miscdev);  in aspeed_lpc_enable_snoop()
207 	/* Enable LPC snoop channel at requested port */  in aspeed_lpc_enable_snoop()
222 		return -EINVAL;  in aspeed_lpc_enable_snoop()
225 	regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);  in aspeed_lpc_enable_snoop()
226 	regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,  in aspeed_lpc_enable_snoop()
228 	if (model_data->has_hicrb_ensnp)  in aspeed_lpc_enable_snoop()
229 		regmap_update_bits(lpc_snoop->regmap, HICRB,  in aspeed_lpc_enable_snoop()
240 		regmap_update_bits(lpc_snoop->regmap, HICR5,  in aspeed_lpc_disable_snoop()
245 		regmap_update_bits(lpc_snoop->regmap, HICR5,  in aspeed_lpc_disable_snoop()
253 	kfifo_free(&lpc_snoop->chan[channel].fifo);  in aspeed_lpc_disable_snoop()
254 	misc_deregister(&lpc_snoop->chan[channel].miscdev);  in aspeed_lpc_disable_snoop()
264 	dev = &pdev->dev;  in aspeed_lpc_snoop_probe()
268 		return -ENOMEM;  in aspeed_lpc_snoop_probe()
270 	lpc_snoop->regmap = syscon_node_to_regmap(  in aspeed_lpc_snoop_probe()
271 			pdev->dev.parent->of_node);  in aspeed_lpc_snoop_probe()
272 	if (IS_ERR(lpc_snoop->regmap)) {  in aspeed_lpc_snoop_probe()
274 		return -ENODEV;  in aspeed_lpc_snoop_probe()
277 	dev_set_drvdata(&pdev->dev, lpc_snoop);  in aspeed_lpc_snoop_probe()
279 	rc = of_property_read_u32_index(dev->of_node, "snoop-ports", 0, &port);  in aspeed_lpc_snoop_probe()
282 		return -ENODEV;  in aspeed_lpc_snoop_probe()
294 	if (of_property_read_u32_index(dev->of_node, "snoop-ports",  in aspeed_lpc_snoop_probe()
306 	struct aspeed_lpc_snoop *lpc_snoop = dev_get_drvdata(&pdev->dev);  in aspeed_lpc_snoop_remove()
324 	{ .compatible = "aspeed,ast2400-lpc-snoop",
326 	{ .compatible = "aspeed,ast2500-lpc-snoop",
345 MODULE_DESCRIPTION("Linux driver to control Aspeed LPC snoop functionality");