net: phy: spi_ks8995: verify chip and determine revision

Since the chip variant is now determined by spi_device_id, verify
family and chip id and determine the revision id.

Signed-off-by: Helmut Buchsbaum <helmut.buchsbaum@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/spi_ks8995.c b/drivers/net/phy/spi_ks8995.c
index e7a215d..5e66d4b 100644 (file)
--- a/drivers/net/phy/spi_ks8995.c
+++ b/drivers/net/phy/spi_ks8995.c
@@ -83,6 +83,8 @@
 
 #define FAMILY_KS8995          0x95
 #define CHIPID_M               0
+#define KS8995_CHIP_ID         0x00
+#define KSZ8864_CHIP_ID                0x01
 
 #define KS8995_CMD_WRITE       0x02U
 #define KS8995_CMD_READ                0x03U
@@ -97,16 +99,22 @@ enum ks8995_chip_variant {
 
 struct ks8995_chip_params {
        char *name;
+       int family_id;
+       int chip_id;
        int regs_size;
 };
 
 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,
        },
        [ksz8864] = {
                .name = "KSZ8864RMN",
+               .family_id = FAMILY_KS8995,
+               .chip_id = KSZ8864_CHIP_ID,
                .regs_size = KSZ8864_REGS_SIZE,
        },
 };
@@ -121,6 +129,7 @@ struct ks8995_switch {
        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[] = {
@@ -263,6 +272,73 @@ 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;
+       default:
+               dev_err(&ks->spi->dev, "unsupported family id: 0x%02x\n", id0);
+               err = -ENODEV;
+               break;
+       }
+err_out:
+       return err;
+}
+
 static const struct bin_attribute ks8995_registers_attr = {
        .attr = {
                .name   = "registers",
@@ -278,7 +354,6 @@ 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;
 
@@ -309,39 +384,12 @@ 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;
-               }
-       }
 
        err = ks8995_reset(ks);
        if (err)
@@ -354,14 +402,8 @@ 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;
 }