[PATCH v2 0/2] W1 drivers for devices used in SGI systems

[PATCH v2 0/2] W1 drivers for devices used in SGI systems

[Thomas Bogendoerfer]

These patches add two W1 drivers. One is a driver for the W1 master in
SGI ASICs, which is used in various machine starting with SGI Origin systems. 
The other is a W1 slave driver for Dallas/Maxim EPROM devices used
in the same type of SGI machines.

Changes in v2:
- added documentation about dev_id field in include/linux/w1.h
- use PTR_ERR_OR_ZERO

Thomas Bogendoerfer (2):
  w1: add 1-wire master driver for IP block found in SGI ASICs
  w1: add DS2501, DS2502, DS2505 EPROM device driver

 drivers/w1/masters/Kconfig           |   9 ++
 drivers/w1/masters/Makefile          |   1 +
 drivers/w1/masters/sgi_w1.c          | 130 ++++++++++++++++
 drivers/w1/slaves/Kconfig            |   6 +
 drivers/w1/slaves/Makefile           |   1 +
 drivers/w1/slaves/w1_ds250x.c        | 290 +++++++++++++++++++++++++++++++++++
 include/linux/platform_data/sgi-w1.h |  15 ++
 include/linux/w1.h                   |   5 +
 8 files changed, 457 insertions(+)
 create mode 100644 drivers/w1/masters/sgi_w1.c
 create mode 100644 drivers/w1/slaves/w1_ds250x.c
 create mode 100644 include/linux/platform_data/sgi-w1.h

-- 
2.13.7

[PATCH v2 1/2] w1: add 1-wire master driver for IP block found in SGI ASICs

[Thomas Bogendoerfer]

Starting with SGI Origin machines nearly every new SGI ASIC contains
an 1-Wire master. They are used for attaching One-Wire prom devices,
which contain information about part numbers, revision numbers,
serial number etc. and MAC addresses for ethernet interfaces.
This patch adds a master driver to support this IP block.
It also adds an extra field dev_id to struct w1_bus_master, which
could be in used in slave drivers for creating unique device names.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/w1/masters/Kconfig           |   9 +++
 drivers/w1/masters/Makefile          |   1 +
 drivers/w1/masters/sgi_w1.c          | 130 +++++++++++++++++++++++++++++++++++
 include/linux/platform_data/sgi-w1.h |  15 ++++
 include/linux/w1.h                   |   5 ++
 5 files changed, 160 insertions(+)
 create mode 100644 drivers/w1/masters/sgi_w1.c
 create mode 100644 include/linux/platform_data/sgi-w1.h

diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig
index 7ae260577901..24b9a8e05f64 100644
--- a/drivers/w1/masters/Kconfig
+++ b/drivers/w1/masters/Kconfig
@@ -65,5 +65,14 @@ config HDQ_MASTER_OMAP
 	  Say Y here if you want support for the 1-wire or HDQ Interface
 	  on an OMAP processor.
 
+config W1_MASTER_SGI
+	tristate "SGI ASIC driver"
+	help
+	  Say Y here if you want support for your 1-wire devices using
+	  SGI ASIC 1-Wire interface
+
+	  This support is also available as a module.  If so, the module
+	  will be called sgi_w1.
+
 endmenu
 
diff --git a/drivers/w1/masters/Makefile b/drivers/w1/masters/Makefile
index 18954cae4256..dae629b7ab49 100644
--- a/drivers/w1/masters/Makefile
+++ b/drivers/w1/masters/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_W1_MASTER_MXC)		+= mxc_w1.o
 obj-$(CONFIG_W1_MASTER_DS1WM)		+= ds1wm.o
 obj-$(CONFIG_W1_MASTER_GPIO)		+= w1-gpio.o
 obj-$(CONFIG_HDQ_MASTER_OMAP)		+= omap_hdq.o
+obj-$(CONFIG_W1_MASTER_SGI)		+= sgi_w1.o
diff --git a/drivers/w1/masters/sgi_w1.c b/drivers/w1/masters/sgi_w1.c
new file mode 100644
index 000000000000..1b2d96b945be
--- /dev/null
+++ b/drivers/w1/masters/sgi_w1.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sgi_w1.c - w1 master driver for one wire support in SGI ASICs
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/sgi-w1.h>
+
+#include <linux/w1.h>
+
+#define MCR_RD_DATA	BIT(0)
+#define MCR_DONE	BIT(1)
+
+#define MCR_PACK(pulse, sample) (((pulse) << 10) | ((sample) << 2))
+
+struct sgi_w1_device {
+	u32 __iomem *mcr;
+	struct w1_bus_master bus_master;
+	char dev_id[64];
+};
+
+static u8 sgi_w1_wait(u32 __iomem *mcr)
+{
+	u32 mcr_val;
+
+	do {
+		mcr_val = readl(mcr);
+	} while (!(mcr_val & MCR_DONE));
+
+	return (mcr_val & MCR_RD_DATA) ? 1 : 0;
+}
+
+/*
+ * this is the low level routine to
+ * reset the device on the One Wire interface
+ * on the hardware
+ */
+static u8 sgi_w1_reset_bus(void *data)
+{
+	struct sgi_w1_device *dev = data;
+	u8 ret;
+
+	writel(MCR_PACK(520, 65), dev->mcr);
+	ret = sgi_w1_wait(dev->mcr);
+	udelay(500); /* recovery time */
+	return ret;
+}
+
+/*
+ * this is the low level routine to read/write a bit on the One Wire
+ * interface on the hardware. It does write 0 if parameter bit is set
+ * to 0, otherwise a write 1/read.
+ */
+static u8 sgi_w1_touch_bit(void *data, u8 bit)
+{
+	struct sgi_w1_device *dev = data;
+	u8 ret;
+
+	if (bit)
+		writel(MCR_PACK(6, 13), dev->mcr);
+	else
+		writel(MCR_PACK(80, 30), dev->mcr);
+
+	ret = sgi_w1_wait(dev->mcr);
+	if (bit)
+		udelay(100); /* recovery */
+	return ret;
+}
+
+static int sgi_w1_probe(struct platform_device *pdev)
+{
+	struct sgi_w1_device *sdev;
+	struct sgi_w1_platform_data *pdata;
+	struct resource *res;
+
+	sdev = devm_kzalloc(&pdev->dev, sizeof(struct sgi_w1_device),
+			    GFP_KERNEL);
+	if (!sdev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sdev->mcr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(sdev->mcr))
+		return PTR_ERR(sdev->mcr);
+
+	sdev->bus_master.data = sdev;
+	sdev->bus_master.reset_bus = sgi_w1_reset_bus;
+	sdev->bus_master.touch_bit = sgi_w1_touch_bit;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (pdata) {
+		strlcpy(sdev->dev_id, pdata->dev_id, sizeof(sdev->dev_id));
+		sdev->bus_master.dev_id = sdev->dev_id;
+	}
+
+	platform_set_drvdata(pdev, sdev);
+
+	return w1_add_master_device(&sdev->bus_master);
+}
+
+/*
+ * disassociate the w1 device from the driver
+ */
+static int sgi_w1_remove(struct platform_device *pdev)
+{
+	struct sgi_w1_device *sdev = platform_get_drvdata(pdev);
+
+	w1_remove_master_device(&sdev->bus_master);
+
+	return 0;
+}
+
+static struct platform_driver sgi_w1_driver = {
+	.driver = {
+		.name = "sgi_w1",
+	},
+	.probe = sgi_w1_probe,
+	.remove = sgi_w1_remove,
+};
+module_platform_driver(sgi_w1_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Thomas Bogendoerfer");
+MODULE_DESCRIPTION("Driver for One-Wire IP in SGI ASICs");
diff --git a/include/linux/platform_data/sgi-w1.h b/include/linux/platform_data/sgi-w1.h
new file mode 100644
index 000000000000..fc6b92e0b942
--- /dev/null
+++ b/include/linux/platform_data/sgi-w1.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SGI One-Wire (W1) IP
+ */
+
+#ifndef PLATFORM_DATA_SGI_W1_H
+#define PLATFORM_DATA_SGI_W1_H
+
+#include <asm/sn/types.h>
+
+struct sgi_w1_platform_data {
+	char dev_id[64];
+};
+
+#endif /* PLATFORM_DATA_SGI_W1_H */
diff --git a/include/linux/w1.h b/include/linux/w1.h
index e0b5156f78fd..7da0c7588e04 100644
--- a/include/linux/w1.h
+++ b/include/linux/w1.h
@@ -118,6 +118,9 @@ typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
  * w1_master* is passed to the slave found callback.
  * u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
  *
+ * @dev_id: Optional device id string, which w1 slaves could use for
+ * creating names, which then give a connection to the w1 master
+ *
  * Note: read_bit and write_bit are very low level functions and should only
  * be used with hardware that doesn't really support 1-wire operations,
  * like a parallel/serial port.
@@ -150,6 +153,8 @@ struct w1_bus_master {
 
 	void		(*search)(void *, struct w1_master *,
 		u8, w1_slave_found_callback);
+
+	char		*dev_id;
 };
 
 /**
-- 
2.13.7

[PATCH v2 2/2] w1: add DS2501, DS2502, DS2505 EPROM device driver

[Thomas Bogendoerfer]

Add a 1-Wire slave driver to support DS250x EPROM deivces. This
slave driver attaches the devices to the NVMEM subsystem for
an easy in-kernel usage.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/w1/slaves/Kconfig     |   6 +
 drivers/w1/slaves/Makefile    |   1 +
 drivers/w1/slaves/w1_ds250x.c | 290 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 297 insertions(+)
 create mode 100644 drivers/w1/slaves/w1_ds250x.c

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index 37aaad26b373..ebed495b9e69 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -101,6 +101,12 @@ config W1_SLAVE_DS2438
 	  Say Y here if you want to use a 1-wire
 	  DS2438 Smart Battery Monitor device support
 
+config W1_SLAVE_DS250X
+	tristate "512b/1kb/16kb EPROM family support"
+	help
+	  Say Y here if you want to use a 1-wire
+	  512b/1kb/16kb EPROM family device (DS250x).
+
 config W1_SLAVE_DS2780
 	tristate "Dallas 2780 battery monitor chip"
 	help
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index eab29f151413..8e9655eaa478 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_W1_SLAVE_DS2431)	+= w1_ds2431.o
 obj-$(CONFIG_W1_SLAVE_DS2805)	+= w1_ds2805.o
 obj-$(CONFIG_W1_SLAVE_DS2433)	+= w1_ds2433.o
 obj-$(CONFIG_W1_SLAVE_DS2438)	+= w1_ds2438.o
+obj-$(CONFIG_W1_SLAVE_DS250X)	+= w1_ds250x.o
 obj-$(CONFIG_W1_SLAVE_DS2780)	+= w1_ds2780.o
 obj-$(CONFIG_W1_SLAVE_DS2781)	+= w1_ds2781.o
 obj-$(CONFIG_W1_SLAVE_DS28E04)	+= w1_ds28e04.o
diff --git a/drivers/w1/slaves/w1_ds250x.c b/drivers/w1/slaves/w1_ds250x.c
new file mode 100644
index 000000000000..e507117444d8
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds250x.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * w1_ds250x.c - w1 family 09/0b/89/91 (DS250x) driver
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/crc16.h>
+
+#include <linux/w1.h>
+#include <linux/nvmem-provider.h>
+
+#define W1_DS2501_UNW_FAMILY    0x91
+#define W1_DS2501_SIZE          64
+
+#define W1_DS2502_FAMILY        0x09
+#define W1_DS2502_UNW_FAMILY    0x89
+#define W1_DS2502_SIZE          128
+
+#define W1_DS2505_FAMILY	0x0b
+#define W1_DS2505_SIZE		2048
+
+#define W1_PAGE_SIZE		32
+
+#define W1_EXT_READ_MEMORY	0xA5
+#define W1_READ_DATA_CRC        0xC3
+
+#define OFF2PG(off)	((off) / W1_PAGE_SIZE)
+
+#define CRC16_INIT		0
+#define CRC16_VALID		0xb001
+
+struct w1_eprom_data {
+	size_t size;
+	int (*read)(struct w1_slave *sl, int pageno);
+	u8 eprom[W1_DS2505_SIZE];
+	DECLARE_BITMAP(page_present, W1_DS2505_SIZE / W1_PAGE_SIZE);
+	char nvmem_name[64];
+};
+
+static int w1_ds2502_read_page(struct w1_slave *sl, int pageno)
+{
+	struct w1_eprom_data *data = sl->family_data;
+	int pgoff = pageno * W1_PAGE_SIZE;
+	int ret = -EIO;
+	u8 buf[3];
+	u8 crc8;
+
+	if (test_bit(pageno, data->page_present))
+		return 0; /* page already present */
+
+	mutex_lock(&sl->master->bus_mutex);
+
+	if (w1_reset_select_slave(sl))
+		goto err;
+
+	buf[0] = W1_READ_DATA_CRC;
+	buf[1] = pgoff & 0xff;
+	buf[2] = pgoff >> 8;
+	w1_write_block(sl->master, buf, 3);
+
+	crc8 = w1_read_8(sl->master);
+	if (w1_calc_crc8(buf, 3) != crc8)
+		goto err;
+
+	w1_read_block(sl->master, &data->eprom[pgoff], W1_PAGE_SIZE);
+
+	crc8 = w1_read_8(sl->master);
+	if (w1_calc_crc8(&data->eprom[pgoff], W1_PAGE_SIZE) != crc8)
+		goto err;
+
+	set_bit(pageno, data->page_present); /* mark page present */
+	ret = 0;
+err:
+	mutex_unlock(&sl->master->bus_mutex);
+	return ret;
+}
+
+static int w1_ds2505_read_page(struct w1_slave *sl, int pageno)
+{
+	struct w1_eprom_data *data = sl->family_data;
+	int redir_retries = 16;
+	int pgoff, epoff;
+	int ret = -EIO;
+	u8 buf[6];
+	u8 redir;
+	u16 crc;
+
+	if (test_bit(pageno, data->page_present))
+		return 0; /* page already present */
+
+	epoff = pgoff = pageno * W1_PAGE_SIZE;
+	mutex_lock(&sl->master->bus_mutex);
+
+retry:
+	if (w1_reset_select_slave(sl))
+		goto err;
+
+	buf[0] = W1_EXT_READ_MEMORY;
+	buf[1] = pgoff & 0xff;
+	buf[2] = pgoff >> 8;
+	w1_write_block(sl->master, buf, 3);
+	w1_read_block(sl->master, buf + 3, 3); /* redir, crc16 */
+	redir = buf[3];
+	crc = crc16(CRC16_INIT, buf, 6);
+
+	if (crc != CRC16_VALID)
+		goto err;
+
+
+	if (redir != 0xff) {
+		redir_retries--;
+		if (redir_retries < 0)
+			goto err;
+
+		pgoff = (redir ^ 0xff) * W1_PAGE_SIZE;
+		goto retry;
+	}
+
+	w1_read_block(sl->master, &data->eprom[epoff], W1_PAGE_SIZE);
+	w1_read_block(sl->master, buf, 2); /* crc16 */
+	crc = crc16(CRC16_INIT, &data->eprom[epoff], W1_PAGE_SIZE);
+	crc = crc16(crc, buf, 2);
+
+	if (crc != CRC16_VALID)
+		goto err;
+
+	set_bit(pageno, data->page_present);
+	ret = 0;
+err:
+	mutex_unlock(&sl->master->bus_mutex);
+	return ret;
+}
+
+static int w1_nvmem_read(void *priv, unsigned int off, void *buf, size_t count)
+{
+	struct w1_slave *sl = priv;
+	struct w1_eprom_data *data = sl->family_data;
+	size_t eprom_size = data->size;
+	int ret;
+	int i;
+
+	if (off > eprom_size)
+		return -EINVAL;
+
+	if ((off + count) > eprom_size)
+		count = eprom_size - off;
+
+	i = OFF2PG(off);
+	do {
+		ret = data->read(sl, i++);
+		if (ret < 0)
+			return ret;
+	} while (i < OFF2PG(off + count));
+
+	memcpy(buf, &data->eprom[off], count);
+	return 0;
+}
+
+static int w1_eprom_add_slave(struct w1_slave *sl)
+{
+	struct w1_eprom_data *data;
+	struct nvmem_device *nvmem;
+	struct nvmem_config nvmem_cfg = {
+		.dev = &sl->dev,
+		.reg_read = w1_nvmem_read,
+		.type = NVMEM_TYPE_OTP,
+		.read_only = true,
+		.word_size = 1,
+		.priv = sl,
+		.id = -1
+	};
+
+	data = devm_kzalloc(&sl->dev, sizeof(struct w1_eprom_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	sl->family_data = data;
+	switch (sl->family->fid) {
+	case W1_DS2501_UNW_FAMILY:
+		data->size = W1_DS2501_SIZE;
+		data->read = w1_ds2502_read_page;
+		break;
+	case W1_DS2502_FAMILY:
+	case W1_DS2502_UNW_FAMILY:
+		data->size = W1_DS2502_SIZE;
+		data->read = w1_ds2502_read_page;
+		break;
+	case W1_DS2505_FAMILY:
+		data->size = W1_DS2505_SIZE;
+		data->read = w1_ds2505_read_page;
+		break;
+	}
+
+	if (sl->master->bus_master->dev_id)
+		snprintf(data->nvmem_name, sizeof(data->nvmem_name),
+			 "%s-%02x-%012llx",
+			 sl->master->bus_master->dev_id, sl->reg_num.family,
+			 (unsigned long long)sl->reg_num.id);
+	else
+		snprintf(data->nvmem_name, sizeof(data->nvmem_name),
+			 "%02x-%012llx",
+			 sl->reg_num.family,
+			 (unsigned long long)sl->reg_num.id);
+
+	nvmem_cfg.name = data->nvmem_name;
+	nvmem_cfg.size = data->size;
+
+	nvmem = devm_nvmem_register(&sl->dev, &nvmem_cfg);
+	return PTR_ERR_OR_ZERO(nvmem);
+}
+
+static struct w1_family_ops w1_eprom_fops = {
+	.add_slave	= w1_eprom_add_slave,
+};
+
+static struct w1_family w1_family_09 = {
+	.fid = W1_DS2502_FAMILY,
+	.fops = &w1_eprom_fops,
+};
+
+static struct w1_family w1_family_0b = {
+	.fid = W1_DS2505_FAMILY,
+	.fops = &w1_eprom_fops,
+};
+
+static struct w1_family w1_family_89 = {
+	.fid = W1_DS2502_UNW_FAMILY,
+	.fops = &w1_eprom_fops,
+};
+
+static struct w1_family w1_family_91 = {
+	.fid = W1_DS2501_UNW_FAMILY,
+	.fops = &w1_eprom_fops,
+};
+
+static int __init w1_ds250x_init(void)
+{
+	int err;
+
+	err = w1_register_family(&w1_family_09);
+	if (err)
+		return err;
+
+	err = w1_register_family(&w1_family_0b);
+	if (err)
+		goto err_0b;
+
+	err = w1_register_family(&w1_family_89);
+	if (err)
+		goto err_89;
+
+	err = w1_register_family(&w1_family_91);
+	if (err)
+		goto err_91;
+
+	return 0;
+
+err_91:
+	w1_unregister_family(&w1_family_89);
+err_89:
+	w1_unregister_family(&w1_family_0b);
+err_0b:
+	w1_unregister_family(&w1_family_09);
+	return err;
+}
+
+static void __exit w1_ds250x_exit(void)
+{
+	w1_unregister_family(&w1_family_09);
+	w1_unregister_family(&w1_family_0b);
+	w1_unregister_family(&w1_family_89);
+	w1_unregister_family(&w1_family_91);
+}
+
+module_init(w1_ds250x_init);
+module_exit(w1_ds250x_exit);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfe@suse.de>");
+MODULE_DESCRIPTION("w1 family driver for DS250x Add Only Memory");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("w1-family-" __stringify(W1_DS2502_FAMILY));
+MODULE_ALIAS("w1-family-" __stringify(W1_DS2505_FAMILY));
+MODULE_ALIAS("w1-family-" __stringify(W1_DS2501_UNW_FAMILY));
+MODULE_ALIAS("w1-family-" __stringify(W1_DS2502_UNW_FAMILY));
-- 
2.13.7