Re: [PATCH net-next v2 01/10] net: dsa: lan9303: Fixed MDIO interface

From: Andrew Lunn
Date: Wed Jul 26 2017 - 12:56:10 EST

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In reply to: Andrew Lunn: "Re: [PATCH net-next v2 01/10] net: dsa: lan9303: Fixed MDIO interface"
Next in thread: Egil Hjelmeland: "Re: [PATCH net-next v2 01/10] net: dsa: lan9303: Fixed MDIO interface"
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On Tue, Jul 25, 2017 at 06:15:44PM +0200, Egil Hjelmeland wrote:
> Fixes after testing on actual HW:
>
> - lan9303_mdio_write()/_read() must multiply register number
> by 4 to get offset
>
> - Indirect access (PMI) to phy register only work in I2C mode. In
> MDIO mode phy registers must be accessed directly. Introduced
> struct lan9303_phy_ops to handle the two modes. Renamed functions
> to clarify.
>
> - lan9303_detect_phy_setup() : Failed MDIO read return 0xffff.
> Handle that.
>
> Signed-off-by: Egil Hjelmeland <privat@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/dsa/lan9303-core.c | 42 +++++++++++++++++++++++++++---------------
> drivers/net/dsa/lan9303.h | 11 +++++++++++
> drivers/net/dsa/lan9303_i2c.c | 2 ++
> drivers/net/dsa/lan9303_mdio.c | 34 ++++++++++++++++++++++++++++++++++
> 4 files changed, 74 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index cd76e61f1fca..e622db586c3d 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -20,6 +20,9 @@
>
> #include "lan9303.h"
>
> +/* 13.2 System Control and Status Registers
> + * Multiply register number by 4 to get address offset.
> + */
> #define LAN9303_CHIP_REV 0x14
> # define LAN9303_CHIP_ID 0x9303
> #define LAN9303_IRQ_CFG 0x15
> @@ -53,6 +56,9 @@
> #define LAN9303_VIRT_PHY_BASE 0x70
> #define LAN9303_VIRT_SPECIAL_CTRL 0x77
>
> +/*13.4 Switch Fabric Control and Status Registers
> + * Accessed indirectly via SWITCH_CSR_CMD, SWITCH_CSR_DATA.
> + */
> #define LAN9303_SW_DEV_ID 0x0000
> #define LAN9303_SW_RESET 0x0001
> #define LAN9303_SW_RESET_RESET BIT(0)
> @@ -242,7 +248,7 @@ static int lan9303_virt_phy_reg_write(struct lan9303 *chip, int regnum, u16 val)
> return regmap_write(chip->regmap, LAN9303_VIRT_PHY_BASE + regnum, val);
> }
>
> -static int lan9303_port_phy_reg_wait_for_completion(struct lan9303 *chip)
> +static int lan9303_indirect_phy_wait_for_completion(struct lan9303 *chip)
> {
> int ret, i;
> u32 reg;
> @@ -262,7 +268,7 @@ static int lan9303_port_phy_reg_wait_for_completion(struct lan9303 *chip)
> return -EIO;
> }
>
> -static int lan9303_port_phy_reg_read(struct lan9303 *chip, int addr, int regnum)
> +static int lan9303_indirect_phy_read(struct lan9303 *chip, int addr, int regnum)
> {
> int ret;
> u32 val;
> @@ -272,7 +278,7 @@ static int lan9303_port_phy_reg_read(struct lan9303 *chip, int addr, int regnum)
>
> mutex_lock(&chip->indirect_mutex);
>
> - ret = lan9303_port_phy_reg_wait_for_completion(chip);
> + ret = lan9303_indirect_phy_wait_for_completion(chip);
> if (ret)
> goto on_error;
>
> @@ -281,7 +287,7 @@ static int lan9303_port_phy_reg_read(struct lan9303 *chip, int addr, int regnum)
> if (ret)
> goto on_error;
>
> - ret = lan9303_port_phy_reg_wait_for_completion(chip);
> + ret = lan9303_indirect_phy_wait_for_completion(chip);
> if (ret)
> goto on_error;
>
> @@ -299,8 +305,8 @@ static int lan9303_port_phy_reg_read(struct lan9303 *chip, int addr, int regnum)
> return ret;
> }
>
> -static int lan9303_phy_reg_write(struct lan9303 *chip, int addr, int regnum,
> - unsigned int val)
> +static int lan9303_indirect_phy_write(struct lan9303 *chip, int addr,
> + int regnum, u16 val)
> {
> int ret;
> u32 reg;
> @@ -311,7 +317,7 @@ static int lan9303_phy_reg_write(struct lan9303 *chip, int addr, int regnum,
>
> mutex_lock(&chip->indirect_mutex);
>
> - ret = lan9303_port_phy_reg_wait_for_completion(chip);
> + ret = lan9303_indirect_phy_wait_for_completion(chip);
> if (ret)
> goto on_error;
>
> @@ -328,6 +334,11 @@ static int lan9303_phy_reg_write(struct lan9303 *chip, int addr, int regnum,
> return ret;
> }
>
> +const struct lan9303_phy_ops lan9303_indirect_phy_ops = {
> + .phy_read = lan9303_indirect_phy_read,
> + .phy_write = lan9303_indirect_phy_write,
> +};
> +
> static int lan9303_switch_wait_for_completion(struct lan9303 *chip)
> {
> int ret, i;
> @@ -427,14 +438,15 @@ static int lan9303_detect_phy_setup(struct lan9303 *chip)
> * Special reg 18 of phy 3 reads as 0x0000, if 'phy_addr_sel_strap' is 0
> * and the IDs are 0-1-2, else it contains something different from
> * 0x0000, which means 'phy_addr_sel_strap' is 1 and the IDs are 1-2-3.
> + * 0xffff is returned for failed MDIO access.

Hi Egil

0xffff is not really a failure. It just means there is nothing on the
bus at that address. The bus has a weak pull-up, so defaults to one.

> */
> - reg = lan9303_port_phy_reg_read(chip, 3, MII_LAN911X_SPECIAL_MODES);
> + reg = chip->ops->phy_read(chip, 3, MII_LAN911X_SPECIAL_MODES);
> if (reg < 0) {
> dev_err(chip->dev, "Failed to detect phy config: %d\n", reg);
> return reg;
> }
>
> - if (reg != 0)
> + if ((reg != 0) && (reg != 0xffff))
> chip->phy_addr_sel_strap = 1;
> else
> chip->phy_addr_sel_strap = 0;
> @@ -719,7 +731,7 @@ static int lan9303_phy_read(struct dsa_switch *ds, int phy, int regnum)
> if (phy > phy_base + 2)
> return -ENODEV;
>
> - return lan9303_port_phy_reg_read(chip, phy, regnum);
> + return chip->ops->phy_read(chip, phy, regnum);
> }
>
> static int lan9303_phy_write(struct dsa_switch *ds, int phy, int regnum,
> @@ -733,7 +745,7 @@ static int lan9303_phy_write(struct dsa_switch *ds, int phy, int regnum,
> if (phy > phy_base + 2)
> return -ENODEV;
>
> - return lan9303_phy_reg_write(chip, phy, regnum, val);
> + return chip->ops->phy_write(chip, phy, regnum, val);
> }
>
> static int lan9303_port_enable(struct dsa_switch *ds, int port,
> @@ -766,13 +778,13 @@ static void lan9303_port_disable(struct dsa_switch *ds, int port,
> switch (port) {
> case 1:
> lan9303_disable_packet_processing(chip, LAN9303_PORT_1_OFFSET);
> - lan9303_phy_reg_write(chip, chip->phy_addr_sel_strap + 1,
> - MII_BMCR, BMCR_PDOWN);
> + lan9303_phy_write(ds, chip->phy_addr_sel_strap + 1,
> + MII_BMCR, BMCR_PDOWN);
> break;
> case 2:
> lan9303_disable_packet_processing(chip, LAN9303_PORT_2_OFFSET);
> - lan9303_phy_reg_write(chip, chip->phy_addr_sel_strap + 2,
> - MII_BMCR, BMCR_PDOWN);
> + lan9303_phy_write(ds, chip->phy_addr_sel_strap + 2,
> + MII_BMCR, BMCR_PDOWN);
> break;
> default:
> dev_dbg(chip->dev,
> diff --git a/drivers/net/dsa/lan9303.h b/drivers/net/dsa/lan9303.h
> index d1512dad2d90..444d00b460e1 100644
> --- a/drivers/net/dsa/lan9303.h
> +++ b/drivers/net/dsa/lan9303.h
> @@ -2,6 +2,15 @@
> #include <linux/device.h>
> #include <net/dsa.h>
>
> +struct lan9303;
> +
> +struct lan9303_phy_ops {
> + /* PHY 1 &2 access*/

A space would be nice here after the &.

> + int (*phy_read)(struct lan9303 *chip, int port, int regnum);
> + int (*phy_write)(struct lan9303 *chip, int port,
> + int regnum, u16 val);
> +};
> +
> struct lan9303 {
> struct device *dev;
> struct regmap *regmap;
> @@ -11,9 +20,11 @@ struct lan9303 {
> bool phy_addr_sel_strap;
> struct dsa_switch *ds;
> struct mutex indirect_mutex; /* protect indexed register access */
> + const struct lan9303_phy_ops *ops;
> };
>
> extern const struct regmap_access_table lan9303_register_set;
> +extern const struct lan9303_phy_ops lan9303_indirect_phy_ops;
>
> int lan9303_probe(struct lan9303 *chip, struct device_node *np);
> int lan9303_remove(struct lan9303 *chip);
> diff --git a/drivers/net/dsa/lan9303_i2c.c b/drivers/net/dsa/lan9303_i2c.c
> index ab3ce0da5071..24ec20f7f444 100644
> --- a/drivers/net/dsa/lan9303_i2c.c
> +++ b/drivers/net/dsa/lan9303_i2c.c
> @@ -63,6 +63,8 @@ static int lan9303_i2c_probe(struct i2c_client *client,
> i2c_set_clientdata(client, sw_dev);
> sw_dev->chip.dev = &client->dev;
>
> + sw_dev->chip.ops = &lan9303_indirect_phy_ops;
> +
> ret = lan9303_probe(&sw_dev->chip, client->dev.of_node);
> if (ret != 0)
> return ret;
> diff --git a/drivers/net/dsa/lan9303_mdio.c b/drivers/net/dsa/lan9303_mdio.c
> index 93c36c0541cf..94df12c5362f 100644
> --- a/drivers/net/dsa/lan9303_mdio.c
> +++ b/drivers/net/dsa/lan9303_mdio.c
> @@ -39,6 +39,7 @@ static void lan9303_mdio_real_write(struct mdio_device *mdio, int reg, u16 val)
> static int lan9303_mdio_write(void *ctx, uint32_t reg, uint32_t val)
> {
> struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
> + reg <<= 2; /* reg num to offset */
>
> mutex_lock(&sw_dev->device->bus->mdio_lock);
> lan9303_mdio_real_write(sw_dev->device, reg, val & 0xffff);
> @@ -56,6 +57,7 @@ static u16 lan9303_mdio_real_read(struct mdio_device *mdio, int reg)
> static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
> {
> struct lan9303_mdio *sw_dev = (struct lan9303_mdio *)ctx;
> + reg <<= 2; /* reg num to offset */
>
> mutex_lock(&sw_dev->device->bus->mdio_lock);
> *val = lan9303_mdio_real_read(sw_dev->device, reg);
> @@ -65,6 +67,36 @@ static int lan9303_mdio_read(void *ctx, uint32_t reg, uint32_t *val)
> return 0;
> }
>
> +int lan9303_mdio_phy_write(struct lan9303 *chip, int phy, int regnum, u16 val)
> +{
> + struct lan9303_mdio *sw_dev = dev_get_drvdata(chip->dev);
> + struct mdio_device *mdio = sw_dev->device;
> +
> + mutex_lock(&mdio->bus->mdio_lock);
> + mdio->bus->write(mdio->bus, phy, regnum, val);
> + mutex_unlock(&mdio->bus->mdio_lock);

It is better to use mdiobus_read/write or if you are nesting mdio
busses, mdiobus_read_nested/mdiobus_write_nested. Please test this
code with lockdep enabled.

And as others have pointed out, there are too many changes in this one
patch.

Thanks
Andrew

Next message: Shuah Khan: "Re: [PATCH] kselftest: exec: make exec test output conform to TAP13"
Previous message: Christopher Lameter: "Re: [v3] mm: Add SLUB free list pointer obfuscation"
In reply to: Andrew Lunn: "Re: [PATCH net-next v2 01/10] net: dsa: lan9303: Fixed MDIO interface"
Next in thread: Egil Hjelmeland: "Re: [PATCH net-next v2 01/10] net: dsa: lan9303: Fixed MDIO interface"
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