ptn3460.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <device/i2c_bus.h>
#include <types.h>
 
#include "ptn3460.h"
 
/**
 * \brief  This function selects one of 7 EDID-tables inside PTN3460
 *         which should be emulated on display port and turn emulation ON
 * @param  *dev         Pointer to the relevant I2C controller
 * @param  edid_num     Number of EDID to emulate (0..6)
 * @return PTN_SUCCESS or error code
 */
static int ptn_select_edid(struct device *dev, uint8_t edid_num)
{
        int status = 0;
        u8 val;
 
        if (edid_num > PTN_MAX_EDID_NUM)
                return PTN_INVALID_EDID;
        val = (edid_num << 1) | PTN_ENABLE_EMULATION;
        status = i2c_dev_writeb_at(dev, PTN_CONFIG_OFF + 4, val);
        return status ? (PTN_BUS_ERROR | status) : PTN_SUCCESS;
}
 
/**
 * \brief This function writes one EDID data structure to PTN3460
 * @param  *dev      Pointer to the relevant I2C controller
 * @param  edid_num  Number of EDID that must be written (0..6)
 * @param  *data     Pointer to a buffer where data to write is stored in
 * @return           PTN_SUCCESS on success or error code
 */
static int ptn3460_write_edid(struct device *dev, u8 edid_num, u8 *data)
{
        int status;
        int i;
 
        if (edid_num > PTN_MAX_EDID_NUM)
                return PTN_INVALID_EDID;
 
        /* First enable access to the desired EDID table */
        status = i2c_dev_writeb_at(dev, PTN_CONFIG_OFF + 5, edid_num);
        if (status)
                return (PTN_BUS_ERROR | status);
 
        /* Now we can simply write EDID data to ptn3460 */
        for (i = 0; i < PTN_EDID_LEN; i++) {
                status = i2c_dev_writeb_at(dev, PTN_EDID_OFF + i, data[i]);
                if (status)
                        return (PTN_BUS_ERROR | status);
        }
        return PTN_SUCCESS;
}
 
/**
 * \brief This function sets up the DP2LVDS-converter to be used with the
 *         appropriate EDID data
 * @param  *dev Pointer to the I2C controller where PTN3460 is attached
 */
static void ptn3460_init(struct device *dev)
{
        struct ptn_3460_config cfg;
        uint8_t edid_data[PTN_EDID_LEN], edid_tab, *ptr = (uint8_t *) &cfg;
        int i, val;
 
        /* Mainboard provides EDID data. */
        if (mb_get_edid(edid_data) != CB_SUCCESS) {
                printk(BIOS_ERR, "PTN3460 error: Unable to get EDID data from mainboard.\n");
                return;
        }
 
        /* Mainboard decides which EDID table has to be used. */
        edid_tab = mb_select_edid_table();
        if (edid_tab > PTN_MAX_EDID_NUM) {
                printk(BIOS_ERR, "PTN3460 error: invalid EDID table (%d) selected.\n",
                       edid_tab);
                return;
        }
        /* Write EDID data into PTN. */
        val = ptn3460_write_edid(dev, edid_tab, edid_data);
        if (val != PTN_SUCCESS) {
                printk(BIOS_ERR, "PTN3460 error: writing EDID data into device failed.\n");
                return;
        }
        /* Activate the selected EDID block. */
        ptn_select_edid(dev, edid_tab);
        /* Read out PTN configuration data. */
        for (i = 0; i < sizeof(struct ptn_3460_config); i++) {
                val = i2c_dev_readb_at(dev, PTN_CONFIG_OFF + i);
                if (val < 0) {
                        printk(BIOS_ERR,
                               "PTN3460 error: Unable to read config data from device.\n");
                        return;
                }
                *ptr++ = (uint8_t)val; /* fill config structure via ptr */
        }
        /* Mainboard can modify the configuration data.
           Write back configuration data to PTN3460 if modified by mainboard */
        if (mb_adjust_cfg(&cfg) == PTN_CFG_MODIFIED) {
                ptr = (uint8_t *) &cfg;
                for (i = 0; i < sizeof(struct ptn_3460_config); i++) {
                        val = i2c_dev_writeb_at(dev, PTN_CONFIG_OFF + i, *ptr++);
                        if (val < 0) {
                                printk(BIOS_ERR,
                                       "PTN3460 error: Unable to write config data.\n");
                                return;
                        }
                }
        }
}
 
__weak enum cb_err mb_get_edid(uint8_t edid_data[0x80])
{
        return CB_ERR;
}
__weak uint8_t mb_select_edid_table(void)
{
        return 0;
}
__weak int mb_adjust_cfg(struct ptn_3460_config *cfg_ptr)
{
        return 0;
}
 
static struct device_operations ptn3460_ops = {
        .read_resources         = noop_read_resources,
        .set_resources          = noop_set_resources,
        .init                   = ptn3460_init,
};
 
static void ptn3460_enable(struct device *dev)
{
        dev->ops = &ptn3460_ops;
}
 
struct chip_operations drivers_i2c_ptn3460_ops = {
        CHIP_NAME("PTN3460")
        .enable_dev = ptn3460_enable
};