#include <linux/module.h>
#include <linux/delay.h>
#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
#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
#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 {
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)
{
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);
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);
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);
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);
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",
};
/* ------------------------------------------------------------------------ */
-
static int ks8995_probe(struct spi_device *spi)
{
- struct ks8995_switch *ks;
- struct ks8995_pdata *pdata;
- u8 ids[2];
- int err;
+ struct ks8995_switch *ks;
+ 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;
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)
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;
}
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);
projects / cascardo / linux.git / blobdiff