/*
 * (C) Copyright 2011
 * egnite GmbH <info@egnite.de>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

/*
 * Ethernut 5 power management support
 *
 * This board may be supplied via USB, IEEE 802.3af PoE or an
 * auxiliary DC input. An on-board ATmega168 microcontroller,
 * the so called power management controller or PMC, is used
 * to select the supply source and to switch on and off certain
 * energy consuming board components. This allows to reduce the
 * total stand-by consumption to less than 70mW.
 *
 * The main CPU communicates with the PMC via I2C. When
 * CONFIG_CMD_BSP is defined in the board configuration file,
 * then the board specific command 'pwrman' becomes available,
 * which allows to manually deal with the PMC.
 *
 * Two distinct registers are provided by the PMC for enabling
 * and disabling specific features. This avoids the often seen
 * read-modify-write cycle or shadow register requirement.
 * Additional registers are available to query the board
 * status and temperature, the auxiliary voltage and to control
 * the green user LED that is integrated in the reset switch.
 *
 * Note, that the AVR firmware of the PMC is released under BSDL.
 *
 * For additional information visit the project home page at
 * http://www.ethernut.de/
 */
#include <common.h>
#include <asm/arch/at91sam9260.h>
#include <asm/arch/at91_common.h>
#include <asm/arch/gpio.h>
#include <asm/io.h>
#include <i2c.h>

#include "ethernut5_pwrman.h"

/* PMC firmware version */
static int pwrman_major;
static int pwrman_minor;

/*
 * Enable Ethernut 5 power management.
 *
 * This function must be called during board initialization.
 * While we are using u-boot's I2C subsystem, it may be required
 * to enable the serial port before calling this function,
 * in particular when debugging is enabled.
 *
 * If board specific commands are not available, we will activate
 * all board components.
 */
void ethernut5_power_init(void)
{
        pwrman_minor = i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_VERS);
        pwrman_major = pwrman_minor >> 4;
        pwrman_minor &= 15;

#ifndef CONFIG_CMD_BSP
        /* Do not modify anything, if we do not have a known version. */
        if (pwrman_major == 2) {
                /* Without board specific commands we enable all features. */
                i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_ENA, ~PWRMAN_ETHRST);
                i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_DIS, PWRMAN_ETHRST);
        }
#endif
}

/*
 * Reset Ethernet PHY.
 *
 * This function allows the re-configure the PHY after
 * changing its strap pins.
 */
void ethernut5_phy_reset(void)
{
        /* Do not modify anything, if we do not have a known version. */
        if (pwrman_major != 2)
                return;

        /*
         * Make sure that the Ethernet clock is enabled and the PHY reset
         * is disabled for at least 100 us.
         */
        i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_ENA, PWRMAN_ETHCLK);
        i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_DIS, PWRMAN_ETHRST);
        udelay(100);

        /*
         * LAN8710 strap pins are
         * PA14 => PHY MODE0
         * PA15 => PHY MODE1
         * PA17 => PHY MODE2 => 111b all capable
         * PA18 => PHY ADDR0 => 0b
         */
        at91_set_pio_input(AT91_PIO_PORTA, 14, 1);
        at91_set_pio_input(AT91_PIO_PORTA, 15, 1);
        at91_set_pio_input(AT91_PIO_PORTA, 17, 1);
        at91_set_pio_input(AT91_PIO_PORTA, 18, 0);

        /* Activate PHY reset for 100 us. */
        i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_ENA, PWRMAN_ETHRST);
        udelay(100);
        i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_DIS, PWRMAN_ETHRST);

        at91_set_pio_input(AT91_PIO_PORTA, 14, 1);
}

/*
 * Output the firmware version we got during initialization.
 */
void ethernut5_print_version(void)
{
        printf("%u.%u\n", pwrman_major, pwrman_minor);
}

/*
 * All code below this point is optional and implements
 * the 'pwrman' command.
 */
#ifdef CONFIG_CMD_BSP

/* Human readable names of PMC features */
char *pwrman_feat[8] = {
        "board", "vbin", "vbout", "mmc",
        "rs232", "ethclk", "ethrst", "wakeup"
};

/*
 * Print all feature names, that have its related flags enabled.
 */
static void print_flagged_features(u8 flags)
{
        int i;

        for (i = 0; i < 8; i++) {
                if (flags & (1 << i))
                        printf("%s ", pwrman_feat[i]);
        }
}

/*
 * Return flags of a given list of feature names.
 *
 * The function stops at the first unknown list entry and
 * returns the number of detected names as a function result.
 */
static int feature_flags(char * const names[], int num, u8 *flags)
{
        int i, j;

        *flags = 0;
        for (i = 0; i < num; i++) {
                for (j = 0; j < 8; j++) {
                        if (strcmp(pwrman_feat[j], names[i]) == 0) {
                                *flags |= 1 << j;
                                break;
                        }
                }
                if (j > 7)
                        break;
        }
        return i;
}

void ethernut5_print_power(void)
{
        u8 flags;
        int i;

        flags = i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_ENA);
        for (i = 0; i < 2; i++) {
                if (flags) {
                        print_flagged_features(flags);
                        printf("%s\n", i ? "off" : "on");
                }
                flags = ~flags;
        }
}

void ethernut5_print_celsius(void)
{
        int val;

        /* Read ADC value from LM50 and return Celsius degrees. */
        val = i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_TEMP);
        val *= 5000;    /* 100mV/degree with 5V reference */
        val += 128;     /* 8 bit resolution */
        val /= 256;
        val -= 450;     /* Celsius offset, still x10 */
        /* Output full degrees. */
        printf("%d\n", (val + 5) / 10);
}

void ethernut5_print_voltage(void)
{
        int val;

        /* Read ADC value from divider and return voltage. */
        val = i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_VAUX);
        /* Resistors are 100k and 12.1k */
        val += 5;
        val *= 180948;
        val /= 100000;
        val++;
        /* Calculation was done in 0.1V units. */
        printf("%d\n", (val + 5) / 10);
}

/*
 * Process the board specific 'pwrman' command.
 */
int do_pwrman(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        u8 val;
        int i;

        if (argc == 1) {
                ethernut5_print_power();
        } else if (argc == 2 && strcmp(argv[1], "reset") == 0) {
                at91_set_pio_output(AT91_PIO_PORTB, 8, 1);
                udelay(100);
                at91_set_pio_output(AT91_PIO_PORTB, 8, 0);
                udelay(100000);
        } else if (argc == 2 && strcmp(argv[1], "temp") == 0) {
                ethernut5_print_celsius();
        } else if (argc == 2 && strcmp(argv[1], "vaux") == 0) {
                ethernut5_print_voltage();
        } else if (argc == 2 && strcmp(argv[1], "version") == 0) {
                ethernut5_print_version();
        } else if (strcmp(argv[1], "led") == 0) {
                /* Control the green status LED. Blink frequency unit
                ** is 0.1s, very roughly. */
                if (argc == 2) {
                        /* No more arguments, output current settings. */
                        val = i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_LEDCTL);
                        printf("led %u %u\n", val >> 4, val & 15);
                } else {
                        /* First argument specifies the on-time. */
                        val = (u8) simple_strtoul(argv[2], NULL, 0);
                        val <<= 4;
                        if (argc > 3) {
                                /* Second argument specifies the off-time. */
                                val |= (u8) (simple_strtoul(argv[3], NULL, 0)
                                                & 15);
                        }
                        /* Update the LED control register. */
                        i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_LEDCTL, val);
                }
        } else {
                /* We expect a list of features followed an optional status. */
                argc--;
                i = feature_flags(&argv[1], argc, &val);
                if (argc == i) {
                        /* We got a list only, print status. */
                        val &= i2c_reg_read(PWRMAN_I2C_ADDR, PWRMAN_REG_STA);
                        if (val) {
                                if (i > 1)
                                        print_flagged_features(val);
                                printf("active\n");
                        } else {
                                printf("inactive\n");
                        }
                } else {
                        /* More arguments. */
                        if (i == 0) {
                                /* No given feature, use despensibles. */
                                val = PWRMAN_DISPENSIBLE;
                        }
                        if (strcmp(argv[i + 1], "on") == 0) {
                                /* Enable features. */
                                i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_ENA,
                                                val);
                        } else if (strcmp(argv[i + 1], "off") == 0) {
                                /* Disable features. */
                                i2c_reg_write(PWRMAN_I2C_ADDR, PWRMAN_REG_DIS,
                                                val);
                        } else {
                                printf("Bad parameter %s\n", argv[i + 1]);
                                return 1;
                        }
                }
        }
        return 0;
}

U_BOOT_CMD(
        pwrman, CONFIG_SYS_MAXARGS, 1, do_pwrman,
        "power management",
                   "- print settings\n"
        "pwrman feature ...\n"
        "       - print status\n"
        "pwrman [feature ...] on|off\n"
        "       - enable/disable specified or all dispensible features\n"
        "pwrman led [on-time [off-time]]\n"
        "       - print or set led blink timer\n"
        "pwrman temp\n"
        "       - print board temperature (Celsius)\n"
        "pwrman vaux\n"
        "       - print auxiliary input voltage\n"
        "pwrman reset\n"
        "       - reset power management controller\n"
        "pwrman version\n"
        "       - print firmware version\n"
        "\n"
        "        features, (*)=dispensible:\n"
        "          board  - 1.8V and 3.3V supply\n"
        "          vbin   - supply via USB device connector\n"
        "          vbout  - USB host connector supply(*)\n"
        "          mmc    - MMC slot supply(*)\n"
        "          rs232  - RS232 driver\n"
        "          ethclk - Ethernet PHY clock(*)\n"
        "          ethrst - Ethernet PHY reset\n"
        "          wakeup - RTC alarm"
);
#endif /* CONFIG_CMD_BSP */