diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml index 03b5567be389..41014f5c01c4 100644 --- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml +++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml @@ -49,6 +49,26 @@ properties: Set if the output SYNCLKO clock should be disabled. Do not mix with microchip,synclko-125. + microchip,io-drive-strength-microamp: + description: + IO Pad Drive Strength + enum: [8000, 16000] + default: 16000 + + microchip,hi-drive-strength-microamp: + description: + High Speed Drive Strength. Controls drive strength of GMII / RGMII / + MII / RMII (except TX_CLK/REFCLKI, COL and CRS) and CLKO_25_125 lines. + enum: [2000, 4000, 8000, 12000, 16000, 20000, 24000, 28000] + default: 24000 + + microchip,lo-drive-strength-microamp: + description: + Low Speed Drive Strength. Controls drive strength of TX_CLK / REFCLKI, + COL, CRS, LEDs, PME_N, NTRP_N, SDO and SDI/SDA/MDIO lines. + enum: [2000, 4000, 8000, 12000, 16000, 20000, 24000, 28000] + default: 8000 + interrupts: maxItems: 1 diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h index 7a57c6088f80..d33db4f86c64 100644 --- a/drivers/net/dsa/microchip/ksz8795_reg.h +++ b/drivers/net/dsa/microchip/ksz8795_reg.h @@ -442,20 +442,6 @@ #define TOS_PRIO_M KS_PRIO_M #define TOS_PRIO_S KS_PRIO_S -#define REG_SW_CTRL_20 0xA3 - -#define SW_GMII_DRIVE_STRENGTH_S 4 -#define SW_DRIVE_STRENGTH_M 0x7 -#define SW_DRIVE_STRENGTH_2MA 0 -#define SW_DRIVE_STRENGTH_4MA 1 -#define SW_DRIVE_STRENGTH_8MA 2 -#define SW_DRIVE_STRENGTH_12MA 3 -#define SW_DRIVE_STRENGTH_16MA 4 -#define SW_DRIVE_STRENGTH_20MA 5 -#define SW_DRIVE_STRENGTH_24MA 6 -#define SW_DRIVE_STRENGTH_28MA 7 -#define SW_MII_DRIVE_STRENGTH_S 0 - #define REG_SW_CTRL_21 0xA4 #define SW_IPV6_MLD_OPTION BIT(3) diff --git a/drivers/net/dsa/microchip/ksz9477_reg.h b/drivers/net/dsa/microchip/ksz9477_reg.h index cba3dba58bc3..504e085aab52 100644 --- a/drivers/net/dsa/microchip/ksz9477_reg.h +++ b/drivers/net/dsa/microchip/ksz9477_reg.h @@ -112,19 +112,6 @@ #define REG_SW_IBA_SYNC__1 0x010C -#define REG_SW_IO_STRENGTH__1 0x010D -#define SW_DRIVE_STRENGTH_M 0x7 -#define SW_DRIVE_STRENGTH_2MA 0 -#define SW_DRIVE_STRENGTH_4MA 1 -#define SW_DRIVE_STRENGTH_8MA 2 -#define SW_DRIVE_STRENGTH_12MA 3 -#define SW_DRIVE_STRENGTH_16MA 4 -#define SW_DRIVE_STRENGTH_20MA 5 -#define SW_DRIVE_STRENGTH_24MA 6 -#define SW_DRIVE_STRENGTH_28MA 7 -#define SW_HI_SPEED_DRIVE_STRENGTH_S 4 -#define SW_LO_SPEED_DRIVE_STRENGTH_S 0 - #define REG_SW_IBA_STATUS__4 0x0110 #define SW_IBA_REQ BIT(31) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 42db7679c360..54048b82db71 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -186,6 +186,72 @@ static const struct ksz_mib_names ksz9477_mib_names[] = { { 0x83, "tx_discards" }, }; +struct ksz_driver_strength_prop { + const char *name; + int offset; + int value; +}; + +enum ksz_driver_strength_type { + KSZ_DRIVER_STRENGTH_HI, + KSZ_DRIVER_STRENGTH_LO, + KSZ_DRIVER_STRENGTH_IO, +}; + +/** + * struct ksz_drive_strength - drive strength mapping + * @reg_val: register value + * @microamp: microamp value + */ +struct ksz_drive_strength { + u32 reg_val; + u32 microamp; +}; + +/* ksz9477_drive_strengths - Drive strength mapping for KSZ9477 variants + * + * This values are not documented in KSZ9477 variants but confirmed by + * Microchip that KSZ9477, KSZ9567, KSZ8567, KSZ9897, KSZ9896, KSZ9563, KSZ9893 + * and KSZ8563 are using same register (drive strength) settings like KSZ8795. + * + * Documentation in KSZ8795CLX provides more information with some + * recommendations: + * - for high speed signals + * 1. 4 mA or 8 mA is often used for MII, RMII, and SPI interface with using + * 2.5V or 3.3V VDDIO. + * 2. 12 mA or 16 mA is often used for MII, RMII, and SPI interface with + * using 1.8V VDDIO. + * 3. 20 mA or 24 mA is often used for GMII/RGMII interface with using 2.5V + * or 3.3V VDDIO. + * 4. 28 mA is often used for GMII/RGMII interface with using 1.8V VDDIO. + * 5. In same interface, the heavy loading should use higher one of the + * drive current strength. + * - for low speed signals + * 1. 3.3V VDDIO, use either 4 mA or 8 mA. + * 2. 2.5V VDDIO, use either 8 mA or 12 mA. + * 3. 1.8V VDDIO, use either 12 mA or 16 mA. + * 4. If it is heavy loading, can use higher drive current strength. + */ +static const struct ksz_drive_strength ksz9477_drive_strengths[] = { + { SW_DRIVE_STRENGTH_2MA, 2000 }, + { SW_DRIVE_STRENGTH_4MA, 4000 }, + { SW_DRIVE_STRENGTH_8MA, 8000 }, + { SW_DRIVE_STRENGTH_12MA, 12000 }, + { SW_DRIVE_STRENGTH_16MA, 16000 }, + { SW_DRIVE_STRENGTH_20MA, 20000 }, + { SW_DRIVE_STRENGTH_24MA, 24000 }, + { SW_DRIVE_STRENGTH_28MA, 28000 }, +}; + +/* ksz8830_drive_strengths - Drive strength mapping for KSZ8830, KSZ8873, .. + * variants. + * This values are documented in KSZ8873 and KSZ8863 datasheets. + */ +static const struct ksz_drive_strength ksz8830_drive_strengths[] = { + { 0, 8000 }, + { KSZ8873_DRIVE_STRENGTH_16MA, 16000 }, +}; + static const struct ksz_dev_ops ksz8_dev_ops = { .setup = ksz8_setup, .get_port_addr = ksz8_get_port_addr, @@ -3530,6 +3596,245 @@ static void ksz_parse_rgmii_delay(struct ksz_device *dev, int port_num, dev->ports[port_num].rgmii_tx_val = tx_delay; } +/** + * ksz_drive_strength_to_reg() - Convert drive strength value to corresponding + * register value. + * @array: The array of drive strength values to search. + * @array_size: The size of the array. + * @microamp: The drive strength value in microamp to be converted. + * + * This function searches the array of drive strength values for the given + * microamp value and returns the corresponding register value for that drive. + * + * Returns: If found, the corresponding register value for that drive strength + * is returned. Otherwise, -EINVAL is returned indicating an invalid value. + */ +static int ksz_drive_strength_to_reg(const struct ksz_drive_strength *array, + size_t array_size, int microamp) +{ + int i; + + for (i = 0; i < array_size; i++) { + if (array[i].microamp == microamp) + return array[i].reg_val; + } + + return -EINVAL; +} + +/** + * ksz_drive_strength_error() - Report invalid drive strength value + * @dev: ksz device + * @array: The array of drive strength values to search. + * @array_size: The size of the array. + * @microamp: Invalid drive strength value in microamp + * + * This function logs an error message when an unsupported drive strength value + * is detected. It lists out all the supported drive strength values for + * reference in the error message. + */ +static void ksz_drive_strength_error(struct ksz_device *dev, + const struct ksz_drive_strength *array, + size_t array_size, int microamp) +{ + char supported_values[100]; + size_t remaining_size; + int added_len; + char *ptr; + int i; + + remaining_size = sizeof(supported_values); + ptr = supported_values; + + for (i = 0; i < array_size; i++) { + added_len = snprintf(ptr, remaining_size, + i == 0 ? "%d" : ", %d", array[i].microamp); + + if (added_len >= remaining_size) + break; + + ptr += added_len; + remaining_size -= added_len; + } + + dev_err(dev->dev, "Invalid drive strength %d, supported values are %s\n", + microamp, supported_values); +} + +/** + * ksz9477_drive_strength_write() - Set the drive strength for specific KSZ9477 + * chip variants. + * @dev: ksz device + * @props: Array of drive strength properties to be applied + * @num_props: Number of properties in the array + * + * This function configures the drive strength for various KSZ9477 chip variants + * based on the provided properties. It handles chip-specific nuances and + * ensures only valid drive strengths are written to the respective chip. + * + * Return: 0 on successful configuration, a negative error code on failure. + */ +static int ksz9477_drive_strength_write(struct ksz_device *dev, + struct ksz_driver_strength_prop *props, + int num_props) +{ + size_t array_size = ARRAY_SIZE(ksz9477_drive_strengths); + int i, ret, reg; + u8 mask = 0; + u8 val = 0; + + if (props[KSZ_DRIVER_STRENGTH_IO].value != -1) + dev_warn(dev->dev, "%s is not supported by this chip variant\n", + props[KSZ_DRIVER_STRENGTH_IO].name); + + if (dev->chip_id == KSZ8795_CHIP_ID || + dev->chip_id == KSZ8794_CHIP_ID || + dev->chip_id == KSZ8765_CHIP_ID) + reg = KSZ8795_REG_SW_CTRL_20; + else + reg = KSZ9477_REG_SW_IO_STRENGTH; + + for (i = 0; i < num_props; i++) { + if (props[i].value == -1) + continue; + + ret = ksz_drive_strength_to_reg(ksz9477_drive_strengths, + array_size, props[i].value); + if (ret < 0) { + ksz_drive_strength_error(dev, ksz9477_drive_strengths, + array_size, props[i].value); + return ret; + } + + mask |= SW_DRIVE_STRENGTH_M << props[i].offset; + val |= ret << props[i].offset; + } + + return ksz_rmw8(dev, reg, mask, val); +} + +/** + * ksz8830_drive_strength_write() - Set the drive strength configuration for + * KSZ8830 compatible chip variants. + * @dev: ksz device + * @props: Array of drive strength properties to be set + * @num_props: Number of properties in the array + * + * This function applies the specified drive strength settings to KSZ8830 chip + * variants (KSZ8873, KSZ8863). + * It ensures the configurations align with what the chip variant supports and + * warns or errors out on unsupported settings. + * + * Return: 0 on success, error code otherwise + */ +static int ksz8830_drive_strength_write(struct ksz_device *dev, + struct ksz_driver_strength_prop *props, + int num_props) +{ + size_t array_size = ARRAY_SIZE(ksz8830_drive_strengths); + int microamp; + int i, ret; + + for (i = 0; i < num_props; i++) { + if (props[i].value == -1 || i == KSZ_DRIVER_STRENGTH_IO) + continue; + + dev_warn(dev->dev, "%s is not supported by this chip variant\n", + props[i].name); + } + + microamp = props[KSZ_DRIVER_STRENGTH_IO].value; + ret = ksz_drive_strength_to_reg(ksz8830_drive_strengths, array_size, + microamp); + if (ret < 0) { + ksz_drive_strength_error(dev, ksz8830_drive_strengths, + array_size, microamp); + return ret; + } + + return ksz_rmw8(dev, KSZ8873_REG_GLOBAL_CTRL_12, + KSZ8873_DRIVE_STRENGTH_16MA, ret); +} + +/** + * ksz_parse_drive_strength() - Extract and apply drive strength configurations + * from device tree properties. + * @dev: ksz device + * + * This function reads the specified drive strength properties from the + * device tree, validates against the supported chip variants, and sets + * them accordingly. An error should be critical here, as the drive strength + * settings are crucial for EMI compliance. + * + * Return: 0 on success, error code otherwise + */ +static int ksz_parse_drive_strength(struct ksz_device *dev) +{ + struct ksz_driver_strength_prop of_props[] = { + [KSZ_DRIVER_STRENGTH_HI] = { + .name = "microchip,hi-drive-strength-microamp", + .offset = SW_HI_SPEED_DRIVE_STRENGTH_S, + .value = -1, + }, + [KSZ_DRIVER_STRENGTH_LO] = { + .name = "microchip,lo-drive-strength-microamp", + .offset = SW_LO_SPEED_DRIVE_STRENGTH_S, + .value = -1, + }, + [KSZ_DRIVER_STRENGTH_IO] = { + .name = "microchip,io-drive-strength-microamp", + .offset = 0, /* don't care */ + .value = -1, + }, + }; + struct device_node *np = dev->dev->of_node; + bool have_any_prop = false; + int i, ret; + + for (i = 0; i < ARRAY_SIZE(of_props); i++) { + ret = of_property_read_u32(np, of_props[i].name, + &of_props[i].value); + if (ret && ret != -EINVAL) + dev_warn(dev->dev, "Failed to read %s\n", + of_props[i].name); + if (ret) + continue; + + have_any_prop = true; + } + + if (!have_any_prop) + return 0; + + switch (dev->chip_id) { + case KSZ8830_CHIP_ID: + return ksz8830_drive_strength_write(dev, of_props, + ARRAY_SIZE(of_props)); + case KSZ8795_CHIP_ID: + case KSZ8794_CHIP_ID: + case KSZ8765_CHIP_ID: + case KSZ8563_CHIP_ID: + case KSZ9477_CHIP_ID: + case KSZ9563_CHIP_ID: + case KSZ9567_CHIP_ID: + case KSZ9893_CHIP_ID: + case KSZ9896_CHIP_ID: + case KSZ9897_CHIP_ID: + return ksz9477_drive_strength_write(dev, of_props, + ARRAY_SIZE(of_props)); + default: + for (i = 0; i < ARRAY_SIZE(of_props); i++) { + if (of_props[i].value == -1) + continue; + + dev_warn(dev->dev, "%s is not supported by this chip variant\n", + of_props[i].name); + } + } + + return 0; +} + int ksz_switch_register(struct ksz_device *dev) { const struct ksz_chip_data *info; @@ -3612,6 +3917,10 @@ int ksz_switch_register(struct ksz_device *dev) for (port_num = 0; port_num < dev->info->port_cnt; ++port_num) dev->ports[port_num].interface = PHY_INTERFACE_MODE_NA; if (dev->dev->of_node) { + ret = ksz_parse_drive_strength(dev); + if (ret) + return ret; + ret = of_get_phy_mode(dev->dev->of_node, &interface); if (ret == 0) dev->compat_interface = interface; diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h index a4de58847dea..ca37b5b87946 100644 --- a/drivers/net/dsa/microchip/ksz_common.h +++ b/drivers/net/dsa/microchip/ksz_common.h @@ -689,6 +689,26 @@ static inline int is_lan937x(struct ksz_device *dev) #define KSZ8_LEGAL_PACKET_SIZE 1518 #define KSZ9477_MAX_FRAME_SIZE 9000 +#define KSZ8873_REG_GLOBAL_CTRL_12 0x0e +/* Drive Strength of I/O Pad + * 0: 8mA, 1: 16mA + */ +#define KSZ8873_DRIVE_STRENGTH_16MA BIT(6) + +#define KSZ8795_REG_SW_CTRL_20 0xa3 +#define KSZ9477_REG_SW_IO_STRENGTH 0x010d +#define SW_DRIVE_STRENGTH_M 0x7 +#define SW_DRIVE_STRENGTH_2MA 0 +#define SW_DRIVE_STRENGTH_4MA 1 +#define SW_DRIVE_STRENGTH_8MA 2 +#define SW_DRIVE_STRENGTH_12MA 3 +#define SW_DRIVE_STRENGTH_16MA 4 +#define SW_DRIVE_STRENGTH_20MA 5 +#define SW_DRIVE_STRENGTH_24MA 6 +#define SW_DRIVE_STRENGTH_28MA 7 +#define SW_HI_SPEED_DRIVE_STRENGTH_S 4 +#define SW_LO_SPEED_DRIVE_STRENGTH_S 0 + #define KSZ9477_REG_PORT_OUT_RATE_0 0x0420 #define KSZ9477_OUT_RATE_NO_LIMIT 0