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Commit 6dca8d45 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'spi_ks8995' 



Helmut Buchsbaum says:

====================
Add support for MICREL KSZ8795CLX 5-port switch

This patch series refactors the spi-ks8995 driver to finally add support
for the MICREL KSZ8795CLX. Additionally support for controlling a GPIO
line for resetting the switch is added.

Helmut

Changes since v2:
 - use GPIO_ACTIVE_LOW according to Andrew's remark.
 - use ePAPR compliant node name in example, thanks to Sergei for
   pointing out
Changes since v1:
 - removed initializing registers from Device Tree following Florian's
   advice
 - fixed GPIO handling for reset according to Andrew's remark.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 74630534 7e406d12

Documentation/devicetree/bindings/net/micrel-ks8995.txt

0 → 100644
+20 −0
Original line number Diff line number Diff line 
Micrel KS8995 SPI controlled Ethernet Switch families



Required properties (according to spi-bus.txt):

- compatible: either "micrel,ks8995", "micrel,ksz8864" or "micrel,ksz8795"



Optional properties:

- reset-gpios : phandle of gpio that will be used to reset chip during probe



Example:



spi-master {

	...

	switch@0 {

		compatible = "micrel,ksz8795";



		reg = <0>;

		spi-max-frequency = <50000000>;

		reset-gpios = <&gpio0 46 GPIO_ACTIVE_LOW>;

	};

};

drivers/net/phy/spi_ks8995.c

+245 −59
Original line number Diff line number Diff line
@@ -18,6 +18,9 @@ 
#include <linux/module.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/of.h>

#include <linux/gpio.h>

#include <linux/of_gpio.h>



#include <linux/spi/spi.h>
@@ -74,6 +77,7 @@ 


#define KS8995_REGS_SIZE	0x80

#define KSZ8864_REGS_SIZE	0x100

#define KSZ8795_REGS_SIZE	0x100



#define ID1_CHIPID_M		0xf

#define ID1_CHIPID_S		4
@@ -82,15 +86,63 @@ 
#define ID1_START_SW		1	/* start the switch */



#define FAMILY_KS8995		0x95

#define FAMILY_KSZ8795		0x87

#define CHIPID_M		0

#define KS8995_CHIP_ID		0x00

#define KSZ8864_CHIP_ID		0x01

#define KSZ8795_CHIP_ID		0x09



#define KS8995_CMD_WRITE	0x02U

#define KS8995_CMD_READ		0x03U



#define KS8995_RESET_DELAY	10 /* usec */



enum ks8995_chip_variant {

	ks8995,

	ksz8864,

	ksz8795,

	max_variant

};



struct ks8995_chip_params {

	char *name;

	int family_id;

	int chip_id;

	int regs_size;

	int addr_width;

	int addr_shift;

};



static const struct ks8995_chip_params ks8995_chip[] = {

	[ks8995] = {

		.name = "KS8995MA",

		.family_id = FAMILY_KS8995,

		.chip_id = KS8995_CHIP_ID,

		.regs_size = KS8995_REGS_SIZE,

		.addr_width = 8,

		.addr_shift = 0,

	},

	[ksz8864] = {

		.name = "KSZ8864RMN",

		.family_id = FAMILY_KS8995,

		.chip_id = KSZ8864_CHIP_ID,

		.regs_size = KSZ8864_REGS_SIZE,

		.addr_width = 8,

		.addr_shift = 0,

	},

	[ksz8795] = {

		.name = "KSZ8795CLX",

		.family_id = FAMILY_KSZ8795,

		.chip_id = KSZ8795_CHIP_ID,

		.regs_size = KSZ8795_REGS_SIZE,

		.addr_width = 12,

		.addr_shift = 1,

	},

};



struct ks8995_pdata {

	/* not yet implemented */

	int reset_gpio;

	enum of_gpio_flags reset_gpio_flags;

};



struct ks8995_switch {
@@ -98,7 +150,17 @@ struct ks8995_switch { 
	struct mutex		lock;

	struct ks8995_pdata	*pdata;

	struct bin_attribute	regs_attr;

	const struct ks8995_chip_params	*chip;

	int			revision_id;

};



static const struct spi_device_id ks8995_id[] = {

	{"ks8995", ks8995},

	{"ksz8864", ksz8864},

	{"ksz8795", ksz8795},

	{ }

};

MODULE_DEVICE_TABLE(spi, ks8995_id);



static inline u8 get_chip_id(u8 val)

{
@@ -110,20 +172,44 @@ static inline u8 get_chip_rev(u8 val) 
	return (val >> ID1_REVISION_S) & ID1_REVISION_M;

}



/* create_spi_cmd - create a chip specific SPI command header

 * @ks: pointer to switch instance

 * @cmd: SPI command for switch

 * @address: register address for command

 *

 * Different chip families use different bit pattern to address the switches

 * registers:

 *

 * KS8995: 8bit command + 8bit address

 * KSZ8795: 3bit command + 12bit address + 1bit TR (?)

 */

static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd,

				    unsigned address)

{

	u16 result = cmd;



	/* make room for address (incl. address shift) */

	result <<= ks->chip->addr_width + ks->chip->addr_shift;

	/* add address */

	result |= address << ks->chip->addr_shift;

	/* SPI protocol needs big endian */

	return cpu_to_be16(result);

}

/* ------------------------------------------------------------------------ */

static int ks8995_read(struct ks8995_switch *ks, char *buf,

		 unsigned offset, size_t count)

{

	u8 cmd[2];

	__be16 cmd;

	struct spi_transfer t[2];

	struct spi_message m;

	int err;



	cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset);

	spi_message_init(&m);



	memset(&t, 0, sizeof(t));



	t[0].tx_buf = cmd;

	t[0].tx_buf = &cmd;

	t[0].len = sizeof(cmd);

	spi_message_add_tail(&t[0], &m);
@@ -131,9 +217,6 @@ static int ks8995_read(struct ks8995_switch *ks, char *buf, 
	t[1].len = count;

	spi_message_add_tail(&t[1], &m);



	cmd[0] = KS8995_CMD_READ;

	cmd[1] = offset;



	mutex_lock(&ks->lock);

	err = spi_sync(ks->spi, &m);

	mutex_unlock(&ks->lock);
@@ -141,20 +224,20 @@ static int ks8995_read(struct ks8995_switch *ks, char *buf, 
	return err ? err : count;

}





static int ks8995_write(struct ks8995_switch *ks, char *buf,

		 unsigned offset, size_t count)

{

	u8 cmd[2];

	__be16 cmd;

	struct spi_transfer t[2];

	struct spi_message m;

	int err;



	cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset);

	spi_message_init(&m);



	memset(&t, 0, sizeof(t));



	t[0].tx_buf = cmd;

	t[0].tx_buf = &cmd;

	t[0].len = sizeof(cmd);

	spi_message_add_tail(&t[0], &m);
@@ -162,9 +245,6 @@ static int ks8995_write(struct ks8995_switch *ks, char *buf, 
	t[1].len = count;

	spi_message_add_tail(&t[1], &m);



	cmd[0] = KS8995_CMD_WRITE;

	cmd[1] = offset;



	mutex_lock(&ks->lock);

	err = spi_sync(ks->spi, &m);

	mutex_unlock(&ks->lock);
@@ -233,6 +313,107 @@ static ssize_t ks8995_registers_write(struct file *filp, struct kobject *kobj, 
	return ks8995_write(ks8995, buf, off, count);

}



/* ks8995_get_revision - get chip revision

 * @ks: pointer to switch instance

 *

 * Verify chip family and id and get chip revision.

 */

static int ks8995_get_revision(struct ks8995_switch *ks)

{

	int err;

	u8 id0, id1, ksz8864_id;



	/* read family id */

	err = ks8995_read_reg(ks, KS8995_REG_ID0, &id0);

	if (err) {

		err = -EIO;

		goto err_out;

	}



	/* verify family id */

	if (id0 != ks->chip->family_id) {

		dev_err(&ks->spi->dev, "chip family id mismatch: expected 0x%02x but 0x%02x read\n",

			ks->chip->family_id, id0);

		err = -ENODEV;

		goto err_out;

	}



	switch (ks->chip->family_id) {

	case FAMILY_KS8995:

		/* try reading chip id at CHIP ID1 */

		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);

		if (err) {

			err = -EIO;

			goto err_out;

		}



		/* verify chip id */

		if ((get_chip_id(id1) == CHIPID_M) &&

		    (get_chip_id(id1) == ks->chip->chip_id)) {

			/* KS8995MA */

			ks->revision_id = get_chip_rev(id1);

		} else if (get_chip_id(id1) != CHIPID_M) {

			/* KSZ8864RMN */

			err = ks8995_read_reg(ks, KS8995_REG_ID1, &ksz8864_id);

			if (err) {

				err = -EIO;

				goto err_out;

			}



			if ((ksz8864_id & 0x80) &&

			    (ks->chip->chip_id == KSZ8864_CHIP_ID)) {

				ks->revision_id = get_chip_rev(id1);

			}



		} else {

			dev_err(&ks->spi->dev, "unsupported chip id for KS8995 family: 0x%02x\n",

				id1);

			err = -ENODEV;

		}

		break;

	case FAMILY_KSZ8795:

		/* try reading chip id at CHIP ID1 */

		err = ks8995_read_reg(ks, KS8995_REG_ID1, &id1);

		if (err) {

			err = -EIO;

			goto err_out;

		}



		if (get_chip_id(id1) == ks->chip->chip_id) {

			ks->revision_id = get_chip_rev(id1);

		} else {

			dev_err(&ks->spi->dev, "unsupported chip id for KSZ8795 family: 0x%02x\n",

				id1);

			err = -ENODEV;

		}

		break;

	default:

		dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);

		err = -ENODEV;

		break;

	}

err_out:

	return err;

}



/* ks8995_parse_dt - setup platform data from devicetree

 * @ks: pointer to switch instance

 *

 * Parses supported DT properties and sets up platform data

 * accordingly.

 */

static void ks8995_parse_dt(struct ks8995_switch *ks)

{

	struct device_node *np = ks->spi->dev.of_node;

	struct ks8995_pdata *pdata = ks->pdata;



	if (!np)

		return;



	pdata->reset_gpio = of_get_named_gpio_flags(np, "reset-gpios", 0,

		&pdata->reset_gpio_flags);

}



static const struct bin_attribute ks8995_registers_attr = {

	.attr = {

		.name   = "registers",
@@ -244,24 +425,58 @@ static const struct bin_attribute ks8995_registers_attr = { 
};



/* ------------------------------------------------------------------------ */



static int ks8995_probe(struct spi_device *spi)

{

	struct ks8995_switch *ks;

	struct ks8995_pdata     *pdata;

	u8      ids[2];

	int err;

	int variant = spi_get_device_id(spi)->driver_data;



	/* Chip description */

	pdata = spi->dev.platform_data;

	if (variant >= max_variant) {

		dev_err(&spi->dev, "bad chip variant %d\n", variant);

		return -ENODEV;

	}



	ks = devm_kzalloc(&spi->dev, sizeof(*ks), GFP_KERNEL);

	if (!ks)

		return -ENOMEM;



	mutex_init(&ks->lock);

	ks->pdata = pdata;

	ks->spi = spi_dev_get(spi);

	ks->chip = &ks8995_chip[variant];



	if (ks->spi->dev.of_node) {

		ks->pdata = devm_kzalloc(&spi->dev, sizeof(*ks->pdata),

					 GFP_KERNEL);

		if (!ks->pdata)

			return -ENOMEM;



		ks->pdata->reset_gpio = -1;



		ks8995_parse_dt(ks);

	}



	if (!ks->pdata)

		ks->pdata = spi->dev.platform_data;



	/* de-assert switch reset */

	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio)) {

		unsigned long flags;



		flags = (ks->pdata->reset_gpio_flags == OF_GPIO_ACTIVE_LOW ?

			 GPIOF_ACTIVE_LOW : 0);



		err = devm_gpio_request_one(&spi->dev,

					    ks->pdata->reset_gpio,

					    flags, "switch-reset");

		if (err) {

			dev_err(&spi->dev,

				"failed to get reset-gpios: %d\n", err);

			return -EIO;

		}



		gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 0);

	}



	spi_set_drvdata(spi, ks);



	spi->mode = SPI_MODE_0;
@@ -272,39 +487,12 @@ static int ks8995_probe(struct spi_device *spi) 
		return err;

	}



	err = ks8995_read(ks, ids, KS8995_REG_ID0, sizeof(ids));

	if (err < 0) {

		dev_err(&spi->dev, "unable to read id registers, err=%d\n",

				err);

	err = ks8995_get_revision(ks);

	if (err)

		return err;

	}



	switch (ids[0]) {

	case FAMILY_KS8995:

		break;

	default:

		dev_err(&spi->dev, "unknown family id:%02x\n", ids[0]);

		return -ENODEV;

	}



	ks->regs_attr.size = ks->chip->regs_size;

	memcpy(&ks->regs_attr, &ks8995_registers_attr, sizeof(ks->regs_attr));

	if (get_chip_id(ids[1]) != CHIPID_M) {

		u8 val;



		/* Check if this is a KSZ8864RMN */

		err = ks8995_read(ks, &val, KSZ8864_REG_ID1, sizeof(val));

		if (err < 0) {

			dev_err(&spi->dev,

				"unable to read chip id register, err=%d\n",

				err);

			return err;

		}

		if ((val & 0x80) == 0) {

			dev_err(&spi->dev, "unknown chip:%02x,0\n", ids[1]);

			return err;

		}

		ks->regs_attr.size = KSZ8864_REGS_SIZE;

	}



	err = ks8995_reset(ks);

	if (err)
@@ -317,14 +505,8 @@ static int ks8995_probe(struct spi_device *spi) 
		return err;

	}



	if (get_chip_id(ids[1]) == CHIPID_M) {

		dev_info(&spi->dev,

			 "KS8995 device found, Chip ID:%x, Revision:%x\n",

			 get_chip_id(ids[1]), get_chip_rev(ids[1]));

	} else {

		dev_info(&spi->dev, "KSZ8864 device found, Revision:%x\n",

			 get_chip_rev(ids[1]));

	}

	dev_info(&spi->dev, "%s device found, Chip ID:%x, Revision:%x\n",

		 ks->chip->name, ks->chip->chip_id, ks->revision_id);



	return 0;

}
@@ -335,17 +517,21 @@ static int ks8995_remove(struct spi_device *spi) 


	sysfs_remove_bin_file(&spi->dev.kobj, &ks->regs_attr);



	/* assert reset */

	if (ks->pdata && gpio_is_valid(ks->pdata->reset_gpio))

		gpiod_set_value(gpio_to_desc(ks->pdata->reset_gpio), 1);



	return 0;

}



/* ------------------------------------------------------------------------ */



static struct spi_driver ks8995_driver = {

	.driver = {

		.name	    = "spi-ks8995",

	},

	.probe	  = ks8995_probe,

	.remove	  = ks8995_remove,

	.id_table = ks8995_id,

};



module_spi_driver(ks8995_driver);