/* * Driver for X-Powers AXP 209 Power Management Unit * * Despite axp209_read/write only working on a byte at a time, there is no such * limitation in the AXP209. * * Copyright (C) 2013 Alexandru Gagniuc * Subject to the GNU GPL v2, or (at your option) any later version. */ #include "axp209.h" #include "chip.h" #include #include #include /* Hide these definitions from the rest of the source, so keep them here */ enum registers { REG_POWER_STATUS = 0x00, REG_POWER_MODE = 0x01, REG_OTG_VBUS = 0x02, REG_CHIP_ID = 0x03, REG_CHIP_PWROUT_CTL = 0x12, REG_DCDC2_VOLTAGE = 0x23, REG_DCDC2_LDO3_CTL = 0x25, REG_DCDC3_VOLTAGE = 0x27, REG_LDO24_VOLTAGE = 0x28, REG_LDO3_VOLTAGE = 0x29, REG_VBUS_IPSOUT = 0x30, REG_PWROFF_VOLTAGE = 0x31, REG_SHTDWN_SETTING = 0x32, }; /* REG_LDO24_VOLTAGE definitions */ #define REG_LDO24_VOLTAGE_LDO2_MASK (0xf << 4) #define REG_LDO24_VOLTAGE_LDO2_VAL(x) ((x << 4) & REG_LDO24_VOLTAGE_LDO2_MASK) #define REG_LDO24_VOLTAGE_LDO4_MASK (0xf << 0) #define REG_LDO24_VOLTAGE_LDO4_VAL(x) ((x << 0) & REG_LDO24_VOLTAGE_LDO4_MASK) /* * Read and write accessors. We only work on one register at a time, but there * is no limitation on the AXP209 as to how many registers we may read or write * in one transaction. * These return the number of bytes read/written, or an error code. In this * case, they return 1 on success, or an error code otherwise. This is done to * work with I²C drivers that return either 0 on success or the number of bytes * actually transferred. */ static int axp209_read(u8 bus, u8 reg, u8 *val) { if (i2c_readb(bus, AXP209_I2C_ADDR, reg, val) < 0) return CB_ERR; return 1; } static int axp209_write(u8 bus, u8 reg, u8 val) { if (i2c_writeb(bus, AXP209_I2C_ADDR, reg, val) < 0) return CB_ERR; return 1; } /** * \brief Identify and initialize an AXP209 on the I²C bus * * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on if an AXP209 is found, or an error code otherwise. */ enum cb_err axp209_init(u8 bus) { u8 id; if (axp209_read(bus, REG_CHIP_ID, &id) != 1) return CB_ERR; /* From U-Boot code : Low 4 bits is chip version */ if ((id & 0x0f) != 0x1) { printk(BIOS_ERR, "[axp209] ID 0x%x does not match\n", id); return CB_ERR; } return CB_SUCCESS; } /** * \brief Configure the output voltage of DC-DC2 converter * * If the requested voltage is not available, the next lowest voltage will * be applied. * Valid values are between 700mV and 2275mV * * @param[in] millivolts voltage in mV units. * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, * CB_ERR_ARG if voltage is out of range, or an error code otherwise. */ enum cb_err axp209_set_dcdc2_voltage(u8 bus, u16 millivolts) { u8 val; if (millivolts < 700 || millivolts > 2275) return CB_ERR_ARG; val = (millivolts - 700) / 25; if (axp209_write(bus, REG_DCDC2_VOLTAGE, val) != 1) return CB_ERR; return CB_SUCCESS; } /** * \brief Configure the output voltage of DC-DC3 converter * * If the requested voltage is not available, the next lowest voltage will * be applied. * Valid values are between 700mV and 3500mV * * @param[in] millivolts voltage in mV units. * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, * CB_ERR_ARG if voltage is out of range, or an error code otherwise. */ enum cb_err axp209_set_dcdc3_voltage(u8 bus, u16 millivolts) { u8 val; if (millivolts < 700 || millivolts > 3500) return CB_ERR_ARG; val = (millivolts - 700) / 25; if (axp209_write(bus, REG_DCDC3_VOLTAGE, val) != 1) return CB_ERR; return CB_SUCCESS; } /** * \brief Configure the output voltage of LDO2 regulator * * If the requested voltage is not available, the next lowest voltage will * be applied. * Valid values are between 700mV and 3300mV * * @param[in] millivolts voltage in mV units. * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, * CB_ERR_ARG if voltage is out of range, or an error code otherwise. */ enum cb_err axp209_set_ldo2_voltage(u8 bus, u16 millivolts) { u8 reg8, val; if (millivolts < 1800 || millivolts > 3300) return CB_ERR_ARG; /* Try to read the register first, and stop here on error */ if (axp209_read(bus, REG_LDO24_VOLTAGE, ®8) != 1) return CB_ERR; val = (millivolts - 1800) / 100; reg8 &= ~REG_LDO24_VOLTAGE_LDO2_MASK; reg8 |= REG_LDO24_VOLTAGE_LDO2_VAL(val); if (axp209_write(bus, REG_LDO24_VOLTAGE, reg8) != 1) return CB_ERR; return CB_SUCCESS; } /** * \brief Configure the output voltage of LDO4 regulator * * If the requested voltage is not available, the next lowest voltage will * be applied. * Valid values are between 700mV and 3500mV. Datasheet lists maximum voltage at * 2250mV, but hardware samples go as high as 3500mV. * * @param[in] millivolts voltage in mV units. * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, * CB_ERR_ARG if voltage is out of range, or an error code otherwise. */ enum cb_err axp209_set_ldo3_voltage(u8 bus, u16 millivolts) { u8 val; /* Datasheet lists 2250 max, but PMU will output up to 3500mV */ if (millivolts < 700 || millivolts > 3500) return CB_ERR_ARG; val = (millivolts - 700) / 25; if (axp209_write(bus, REG_LDO3_VOLTAGE, val) != 1) return CB_ERR; return CB_SUCCESS; } /** * \brief Configure the output voltage of DC-DC2 converter * * If the requested voltage is not available, the next lowest voltage will * be applied. * Valid values are between 1250V and 3300mV * * @param[in] millivolts voltage in mV units. * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, * CB_ERR_ARG if voltage is out of range, or an error code otherwise. */ enum cb_err axp209_set_ldo4_voltage(u8 bus, u16 millivolts) { u8 reg8, val; if (millivolts < 1250 || millivolts > 3300) return CB_ERR_ARG; /* Try to read the register first, and stop here on error */ if (axp209_read(bus, REG_LDO24_VOLTAGE, ®8) != 1) return CB_ERR; if (millivolts <= 2000) val = (millivolts - 1200) / 100; else if (millivolts <= 2700) val = 9 + (millivolts - 2500) / 100; else if (millivolts <= 2800) val = 11; else val = 12 + (millivolts - 3000) / 100; reg8 &= ~REG_LDO24_VOLTAGE_LDO4_MASK; reg8 |= REG_LDO24_VOLTAGE_LDO4_VAL(val); if (axp209_write(bus, REG_LDO24_VOLTAGE, reg8) != 1) return CB_ERR; return CB_SUCCESS; } static const struct { enum cb_err (*set_voltage) (u8 bus, u16 mv); const char *name; } vtable[] = { { .set_voltage = axp209_set_dcdc2_voltage, .name = "DCDC2", }, { .set_voltage = axp209_set_dcdc3_voltage, .name = "DCDC3", }, { .set_voltage = axp209_set_ldo2_voltage, .name = "LDO2", }, { .set_voltage = axp209_set_ldo3_voltage, .name = "LDO3", }, { .set_voltage = axp209_set_ldo4_voltage, .name = "LDO4", } }; static enum cb_err set_rail(u8 bus, int idx, u16 mv) { enum cb_err err; const char *name = vtable[idx].name; /* If voltage isn't specified, don't touch the rail */ if (mv == 0) { printk(BIOS_DEBUG, "[axp209] Skipping %s configuration\n", name); return CB_SUCCESS; } if ((err = vtable[idx].set_voltage(bus, mv) != CB_SUCCESS)) { printk(BIOS_ERR, "[axp209] Failed to set %s to %u mv\n", name, mv); return err; } return CB_SUCCESS; } /** * \brief Configure all voltage rails * * Configure all converters and regulators from devicetree config. If any of the * voltages are not declared (i.e. are zero), the respective rail will not be * reconfigured, and retain its powerup voltage. * * @param[in] cfg pointer to @ref drivers_xpowers_axp209_config structure * @param[in] bus I²C bus to which the AXP209 is connected * @return CB_SUCCES on success, or an error code otherwise. */ enum cb_err axp209_set_voltages(u8 bus, const struct drivers_xpowers_axp209_config *cfg) { enum cb_err err; /* Don't worry about what the error is. Console prints that */ err = set_rail(bus, 0, cfg->dcdc2_voltage_mv); err |= set_rail(bus, 1, cfg->dcdc3_voltage_mv); err |= set_rail(bus, 2, cfg->ldo2_voltage_mv); err |= set_rail(bus, 3, cfg->ldo3_voltage_mv); err |= set_rail(bus, 4, cfg->ldo4_voltage_mv); if (err != CB_SUCCESS) return CB_ERR; return CB_SUCCESS; } /* * Usually, the AXP209 is enabled and configured in romstage, so there is no * need for a full ramstage driver. Hence .enable_dev is NULL. */ #ifndef __PRE_RAM__ struct chip_operations drivers_xpowers_axp209_config = { CHIP_NAME("X-Powers AXP 209 Power Management Unit") .enable_dev = NULL, }; #endif /* __PRE_RAM__ */