rtd2132.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <delay.h>
#include <device/device.h>
#include <device/smbus.h>
#include <device/pci.h>
#include "chip.h"
 
/* Chip commands */
#define RTD2132_COMMAND                 0x01
#define RTD2132_DATA                    0x00
#define RTD2132_FIRMWARE                0x80
#define  RTD2132_FIRMWARE_START         0x00
#define  RTD2132_FIRMWARE_STOP          0x01
 
/* Panel Power Sequence Timing Registers. */
#define RTD2132_COMMAND_PWR_SEQ_T1      0x32 /* 1ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T2      0x33 /* 4ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T3      0x34 /* 1ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T4      0x35 /* 1ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T5      0x36 /* 4ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T6      0x37 /* 1ms units. */
#define RTD2132_COMMAND_PWR_SEQ_T7      0x38 /* 4ms units. */
 
/* Spread spectrum configuration */
#define RTD2132_COMMAND_SSCG_CONFIG_0   0x39
#define  RTD2132_SSCG_ENABLE            0xa0
#define  RTD2132_SSCG_DISABLE           0x20
#define RTD2132_COMMAND_SSCG_CONFIG_1   0x3a
#define  RTD2132_SSCG_CONFIG_DISABLED   0x01    /* DISABLED */
#define  RTD2132_SSCG_CONFIG_0_5        0x07    /* 0.5% */
#define  RTD2132_SSCG_CONFIG_1_0        0x0f    /* 1.0% */
#define  RTD2132_SSCG_CONFIG_1_5        0x16    /* 1.5% */
 
/* LVDS Swap */
#define RTD2132_COMMAND_LVDS_SWAP       0x3b
#define  RTD2132_LVDS_SWAP_DUAL         0x80
#define  RTD2132_LVDS_SWAP_NORMAL       0x04
#define  RTD2132_LVDS_SWAP_MIRROR       0x14
#define  RTD2132_LVDS_SWAP_P_N          0x24
#define  RTD2132_LVDS_SWAP_MIRROR_P_N   0x34
#define  RTD2132_LVDS_SWAP_R_L          0x0c
 
/* Configuration values from devicetree */
#define RTD2132_SSCG_PERCENT_0_0        0x00    /* DISABLED */
#define RTD2132_SSCG_PERCENT_0_5        0x05    /* 0.5% */
#define RTD2132_SSCG_PERCENT_1_0        0x10    /* 1.0% */
#define RTD2132_SSCG_PERCENT_1_5        0x15    /* 1.5% */
 
#define  RTD2132_LVDS_SWAP_CFG_DUAL             0x80
#define  RTD2132_LVDS_SWAP_CFG_NORMAL           0x00
#define  RTD2132_LVDS_SWAP_CFG_MIRROR           0x01
#define  RTD2132_LVDS_SWAP_CFG_P_N              0x02
#define  RTD2132_LVDS_SWAP_CFG_MIRROR_P_N       0x03
#define  RTD2132_LVDS_SWAP_CFG_R_L              0x04
 
#define RTD2132_DEBUG_REG 0
 
static void rtd2132_write_reg(struct device *dev, u8 reg, u8 value)
{
        if (RTD2132_DEBUG_REG)
                printk(BIOS_DEBUG, "RTD2132 0x%02x <- 0x%02x\n", reg, value);
        smbus_write_byte(dev, RTD2132_COMMAND, reg);
        smbus_write_byte(dev, RTD2132_DATA, value);
}
 
static void rtd2132_firmware_stop(struct device *dev)
{
        smbus_write_byte(dev, RTD2132_FIRMWARE, RTD2132_FIRMWARE_STOP);
        mdelay(60);
}
 
static void rtd2132_firmware_start(struct device *dev)
{
        smbus_write_byte(dev, RTD2132_FIRMWARE, RTD2132_FIRMWARE_START);
}
 
static void rtd2132_pps(struct device *dev, struct drivers_i2c_rtd2132_config *cfg)
{
        /* T2, T5, and T7 register values are in units of 4ms. */
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T1, cfg->t1);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T2, cfg->t2 / 4);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T3, cfg->t3);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T4, cfg->t4);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T5, cfg->t5 / 4);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T6, cfg->t6);
        rtd2132_write_reg(dev, RTD2132_COMMAND_PWR_SEQ_T7, cfg->t7 / 4);
}
 
static void rtd2132_sscg_enable(struct device *dev, u8 sscg_percent)
{
        /* SSCG_Config_0 */
        rtd2132_write_reg(dev, RTD2132_COMMAND_SSCG_CONFIG_0,
                          RTD2132_SSCG_ENABLE);
 
        /* SSCG_Config_1 */
        rtd2132_write_reg(dev, RTD2132_COMMAND_SSCG_CONFIG_1, sscg_percent);
}
 
static void rtd2132_sscg_disable(struct device *dev)
{
        /* SSCG_Config_0 */
        rtd2132_write_reg(dev, RTD2132_COMMAND_SSCG_CONFIG_0,
                          RTD2132_SSCG_DISABLE);
 
        /* SSCG_Config_1 */
        rtd2132_write_reg(dev, RTD2132_COMMAND_SSCG_CONFIG_1,
                          RTD2132_SSCG_CONFIG_DISABLED);
}
 
static void rtd2132_sscg(struct device *dev, struct drivers_i2c_rtd2132_config *cfg)
{
        switch (cfg->sscg_percent) {
        case RTD2132_SSCG_PERCENT_0_0:
                printk(BIOS_INFO, "RTD2132: Disable Spread Spectrum\n");
                rtd2132_sscg_disable(dev);
                break;
        case RTD2132_SSCG_PERCENT_0_5:
                printk(BIOS_INFO, "RTD2132: Enable 0.5%% Spread Spectrum\n");
                rtd2132_sscg_enable(dev, RTD2132_SSCG_CONFIG_0_5);
                break;
        case RTD2132_SSCG_PERCENT_1_0:
                printk(BIOS_INFO, "RTD2132: Enable 1.0%% Spread Spectrum\n");
                rtd2132_sscg_enable(dev, RTD2132_SSCG_CONFIG_1_0);
                break;
        case RTD2132_SSCG_PERCENT_1_5:
                printk(BIOS_INFO, "RTD2132: Enable 1.5%% Spread Spectrum\n");
                rtd2132_sscg_enable(dev, RTD2132_SSCG_CONFIG_1_5);
                break;
        default:
                printk(BIOS_ERR, "RTD2132: Invalid Spread Spectrum 0x%02x\n",
                       cfg->sscg_percent);
        }
}
 
static void rtd2132_lvds_swap(struct device *dev,
                              struct drivers_i2c_rtd2132_config *cfg)
{
        u8 swap_value = RTD2132_LVDS_SWAP_NORMAL;
 
        switch (cfg->lvds_swap & ~RTD2132_LVDS_SWAP_CFG_DUAL) {
        case RTD2132_LVDS_SWAP_CFG_NORMAL:
                swap_value = RTD2132_LVDS_SWAP_NORMAL;
                break;
        case RTD2132_LVDS_SWAP_CFG_MIRROR:
                swap_value = RTD2132_LVDS_SWAP_MIRROR;
                break;
        case RTD2132_LVDS_SWAP_CFG_P_N:
                swap_value = RTD2132_LVDS_SWAP_P_N;
                break;
        case RTD2132_LVDS_SWAP_CFG_MIRROR_P_N:
                swap_value = RTD2132_LVDS_SWAP_MIRROR_P_N;
                break;
        case RTD2132_LVDS_SWAP_CFG_R_L:
                swap_value = RTD2132_LVDS_SWAP_R_L;
                break;
        default:
                printk(BIOS_ERR, "RTD2132: Invalid LVDS swap value 0x%02x\n",
                       cfg->lvds_swap);
        }
 
        if (cfg->lvds_swap & RTD2132_LVDS_SWAP_CFG_DUAL)
                swap_value |= RTD2132_LVDS_SWAP_DUAL;
 
        printk(BIOS_INFO, "RTD2132: LVDS Swap 0x%02x\n", swap_value);
 
        rtd2132_write_reg(dev, RTD2132_COMMAND_LVDS_SWAP, swap_value);
}
 
static void rtd2132_defaults(struct device *dev)
{
        static const struct def_setting {
                u8 reg;
                u8 value;
        } def_settings[] = {
                { 0x3c, 0x06 },
                { 0x3d, 0x38 },
                { 0x3e, 0x73 },
                { 0x3f, 0x33 },
                { 0x06, 0x90 },
                { 0x06, 0xb0 },
                { 0x06, 0x80 },
        };
        int i;
 
        for (i = 0; i < ARRAY_SIZE(def_settings); i++)
                rtd2132_write_reg(dev, def_settings[i].reg,
                                  def_settings[i].value);
}
 
static void rtd2132_setup(struct device *dev)
{
        struct drivers_i2c_rtd2132_config *config = dev->chip_info;
 
        if (!config)
                return;
 
        /* Stop running firmware */
        rtd2132_firmware_stop(dev);
 
        /* Panel Power Sequencing Settings. */
        rtd2132_pps(dev, config);
 
        /* Spread spectrum configuration */
        rtd2132_sscg(dev, config);
 
        /* LVDS Swap Setting. */
        rtd2132_lvds_swap(dev, config);
 
        /* Default settings. */
        rtd2132_defaults(dev);
 
        /* Start firmware */
        rtd2132_firmware_start(dev);
}
 
static void rtd2132_init(struct device *dev)
{
        if (dev->enabled && dev->path.type == DEVICE_PATH_I2C &&
            ops_smbus_bus(get_pbus_smbus(dev))) {
                rtd2132_setup(dev);
        }
}
 
static struct device_operations rtd2132_operations = {
        .read_resources         = noop_read_resources,
        .set_resources          = noop_set_resources,
        .init                   = rtd2132_init,
};
 
static void enable_dev(struct device *dev)
{
        dev->ops = &rtd2132_operations;
}
 
struct chip_operations drivers_i2c_rtd2132_ops = {
        CHIP_NAME("Realtek RTD2132 LVDS Bridge")
        .enable_dev = enable_dev,
};