w1/masters/sgi_w1.c

1 // SPDX-License-Identifier: GPL-2.0
3  * sgi_w1.c - w1 master driver for one wire support in SGI ASICs
13 #include <linux/platform_data/sgi-w1.h>
20 #define MCR_PACK(pulse, sample) (((pulse) << 10) | ((sample) << 2))
41  * reset the device on the One Wire interface
49 	writel(MCR_PACK(520, 65), dev->mcr);  in sgi_w1_reset_bus()
50 	ret = sgi_w1_wait(dev->mcr);  in sgi_w1_reset_bus()
56  * this is the low level routine to read/write a bit on the One Wire
66 		writel(MCR_PACK(6, 13), dev->mcr);  in sgi_w1_touch_bit()
68 		writel(MCR_PACK(80, 30), dev->mcr);  in sgi_w1_touch_bit()
70 	ret = sgi_w1_wait(dev->mcr);  in sgi_w1_touch_bit()
81 	sdev = devm_kzalloc(&pdev->dev, sizeof(struct sgi_w1_device),  in sgi_w1_probe()
84 		return -ENOMEM;  in sgi_w1_probe()
86 	sdev->mcr = devm_platform_ioremap_resource(pdev, 0);  in sgi_w1_probe()
87 	if (IS_ERR(sdev->mcr))  in sgi_w1_probe()
88 		return PTR_ERR(sdev->mcr);  in sgi_w1_probe()
90 	sdev->bus_master.data = sdev;  in sgi_w1_probe()
91 	sdev->bus_master.reset_bus = sgi_w1_reset_bus;  in sgi_w1_probe()
92 	sdev->bus_master.touch_bit = sgi_w1_touch_bit;  in sgi_w1_probe()
94 	pdata = dev_get_platdata(&pdev->dev);  in sgi_w1_probe()
96 		strscpy(sdev->dev_id, pdata->dev_id, sizeof(sdev->dev_id));  in sgi_w1_probe()
97 		sdev->bus_master.dev_id = sdev->dev_id;  in sgi_w1_probe()
102 	return w1_add_master_device(&sdev->bus_master);  in sgi_w1_probe()
112 	w1_remove_master_device(&sdev->bus_master);  in sgi_w1_remove()
126 MODULE_DESCRIPTION("Driver for One-Wire IP in SGI ASICs");