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/* SPDX-License-Identifier: GPL-2.0-only */
#include <assert.h>
#include <amdblocks/acpimmio.h>
#include <amdblocks/gpio.h>
#include <amdblocks/gpio_defs.h>
#include <amdblocks/i2c.h>
#include <console/console.h>
#include <delay.h>
#include <device/device.h>
#include <device/i2c.h>
#include <device/mmio.h>
#include <drivers/i2c/designware/dw_i2c.h>
#include <gpio.h>
#include <types.h>
#define MAX_PIN_COUNT 4
uintptr_t dw_i2c_base_address(unsigned int bus)
{
size_t num_ctrlrs;
const struct soc_i2c_ctrlr_info *ctrlr = soc_get_i2c_ctrlr_info(&num_ctrlrs);
if (bus >= num_ctrlrs) {
printk(BIOS_ERR, "Bus ID %u is >= number of I2C controllers %zu\n",
bus, num_ctrlrs);
return 0;
}
return ctrlr[bus].bar;
}
const struct dw_i2c_bus_config *dw_i2c_get_soc_cfg(unsigned int bus)
{
size_t num_buses = 0;
const struct dw_i2c_bus_config *cfg = soc_get_i2c_bus_config(&num_buses);
if (bus >= num_buses) {
printk(BIOS_ERR, "Bus ID %u is >= number of I2C buses %zu\n", bus, num_buses);
return NULL;
}
return &cfg[bus];
}
static const char *i2c_acpi_name(const struct device *dev)
{
size_t i;
size_t num_ctrlrs;
const struct soc_i2c_ctrlr_info *ctrlr = soc_get_i2c_ctrlr_info(&num_ctrlrs);
if (!(uintptr_t)dev->path.mmio.addr)
die("NULL MMIO address at %s\n", __func__);
for (i = 0; i < num_ctrlrs; i++) {
if ((uintptr_t)dev->path.mmio.addr == ctrlr[i].bar)
return ctrlr[i].acpi_name;
}
printk(BIOS_ERR, "%s: Could not find %lu\n", __func__, (uintptr_t)dev->path.mmio.addr);
return NULL;
}
int dw_i2c_soc_dev_to_bus(const struct device *dev)
{
size_t i;
size_t num_ctrlrs;
const struct soc_i2c_ctrlr_info *ctrlr = soc_get_i2c_ctrlr_info(&num_ctrlrs);
if (!(uintptr_t)dev->path.mmio.addr)
die("NULL MMIO address at %s\n", __func__);
for (i = 0; i < num_ctrlrs; i++) {
if ((uintptr_t)dev->path.mmio.addr == ctrlr[i].bar)
return i;
}
printk(BIOS_ERR, "%s: Could not find %lu\n", __func__, (uintptr_t)dev->path.mmio.addr);
return -1;
}
static void dw_i2c_soc_init(bool is_early_init)
{
unsigned int bus;
size_t num_buses = 0, num_ctrlrs = 0;
const struct dw_i2c_bus_config *cfg = soc_get_i2c_bus_config(&num_buses);
const struct soc_i2c_ctrlr_info *ctrlr = soc_get_i2c_ctrlr_info(&num_ctrlrs);
/* Ensure that the number of controllers in devicetree and SoC match. */
assert(num_buses == num_ctrlrs);
for (bus = 0; bus < num_buses; bus++, cfg++, ctrlr++) {
/*
* Skip initialization when controller is in peripheral mode or base address
* is not configured or is not the expected stage to initialize.
*/
if (ctrlr->mode == I2C_PERIPHERAL_MODE || !ctrlr->bar ||
cfg->early_init != is_early_init)
continue;
if (dw_i2c_init(bus, cfg) != CB_SUCCESS) {
printk(BIOS_ERR, "Failed to init i2c bus %u\n", bus);
continue;
}
soc_i2c_misc_init(bus, cfg);
}
}
void i2c_soc_early_init(void)
{
dw_i2c_soc_init(true);
}
void i2c_soc_init(void)
{
dw_i2c_soc_init(false);
}
static void i2c_read_resources(struct device *dev)
{
mmio_resource(dev, 0, dev->path.mmio.addr / KiB, 4);
}
struct device_operations soc_amd_i2c_mmio_ops = {
.read_resources = i2c_read_resources,
.set_resources = noop_set_resources,
.scan_bus = scan_smbus,
.acpi_name = i2c_acpi_name,
.acpi_fill_ssdt = dw_i2c_acpi_fill_ssdt,
.ops_i2c_bus = &dw_i2c_bus_ops,
};
static void drive_scl(const struct soc_i2c_peripheral_reset_info *reset_info, int val)
{
size_t j;
for (j = 0; j < reset_info->num_pins; j++) {
if (reset_info->i2c_scl_reset_mask & reset_info->i2c_scl[j].pin_mask)
gpio_set(reset_info->i2c_scl[j].pin.gpio, val);
}
gpio_get(0); /* Flush posted write */
/*
* TODO(b/183010197): 4usec gets 85KHz for 1 pin, 70KHz for 4 pins. Ensure this delay
* works fine for all SoCs and make this delay configurable if required.
*/
udelay(4);
}
void sb_reset_i2c_peripherals(const struct soc_i2c_peripheral_reset_info *reset_info)
{
struct soc_amd_gpio_register_save save_table[MAX_PIN_COUNT];
size_t i;
if (!reset_info || !reset_info->i2c_scl || !reset_info->num_pins ||
!reset_info->i2c_scl_reset_mask)
return;
assert(reset_info->num_pins <= MAX_PIN_COUNT);
/* Save and reprogram I2C SCL pins */
for (i = 0; i < reset_info->num_pins; i++) {
/* To program I2C pins without destroying their programming, the registers
that will be changed need to be saved first */
gpio_save_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
/* Program SCL GPIO as output driven high */
gpio_configure_pads(&reset_info->i2c_scl[i].pin, 1);
}
/*
* Toggle SCL back and forth 9 times under 100KHz. A single read is
* needed after the writes to force the posted write to complete.
*/
for (i = 0; i < 9; i++) {
drive_scl(reset_info, 1);
drive_scl(reset_info, 0);
}
/* Restore I2C pins. */
for (i = 0; i < reset_info->num_pins; i++)
gpio_restore_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
}
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