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

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
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>;
};
};
......@@ -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);
......
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