drivers/edgetpu/janeiro-pm.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Janeiro EdgeTPU power management support
 *
 * Copyright (C) 2020 Google, Inc.
 */

#include <linux/delay.h>
#include <linux/iopoll.h>

#include "edgetpu-config.h"
#include "edgetpu-internal.h"
#include "edgetpu-mobile-platform.h"
#include "mobile-pm.h"

#define TPU_DEFAULT_POWER_STATE		TPU_ACTIVE_UUD

#include "mobile-pm.c"

#define SHUTDOWN_DELAY_US_MIN		20
#define SHUTDOWN_DELAY_US_MAX		20
#define BOOTUP_DELAY_US_MIN		200
#define BOOTUP_DELAY_US_MAX		250
#define SHUTDOWN_MAX_DELAY_COUNT	1000

#define EDGETPU_PSM0_CFG 0x1c1880
#define EDGETPU_PSM0_START 0x1c1884
#define EDGETPU_PSM0_STATUS 0x1c1888
#define EDGETPU_PSM1_CFG 0x1c2880
#define EDGETPU_PSM1_START 0x1c2884
#define EDGETPU_PSM1_STATUS 0x1c2888
#define EDGETPU_LPM_CHANGE_TIMEOUT 30000
#define EDGETPU_PSM0_GPOUT_WRT_LO 0x1c18a8
#define EDGETPU_PSM0_GPOUT_WRT_HI 0x1c18ac
#define EDGETPU_PSM0_DEBUGCFG 0x1c188c
#define EDGETPU_PSM0_RECOVER_VAL 125888

static void janeiro_lpm_down(struct edgetpu_dev *etdev)
{
	int timeout_cnt = 0;
	u32 val, val1;

	do {
		/* Manually delay 20us per retry till LPM shutdown finished */
		usleep_range(SHUTDOWN_DELAY_US_MIN, SHUTDOWN_DELAY_US_MAX);
		val = edgetpu_dev_read_32_sync(etdev, EDGETPU_REG_LPM_CONTROL);
		if ((val & 0x1000) || (val == 0))
			break;
		timeout_cnt++;
	} while (timeout_cnt < SHUTDOWN_MAX_DELAY_COUNT);
	if (timeout_cnt == SHUTDOWN_MAX_DELAY_COUNT) {
		/* Log the issue then continue to perform the shutdown forcefully. */
		etdev_err(etdev, "LPM shutdown failure, attempt to recover\n");
		val = edgetpu_dev_read_32_sync(etdev, EDGETPU_PSM0_STATUS);
		val1 = edgetpu_dev_read_32_sync(etdev, EDGETPU_PSM1_STATUS);
		etdev_err(etdev, "PSM0_STATUS: %#x, PSM1_STATUS: %#x\n", val, val1);

		edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_GPOUT_WRT_LO,
					  EDGETPU_PSM0_RECOVER_VAL);
		edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_GPOUT_WRT_HI, 0);
		val = edgetpu_dev_read_32_sync(etdev, EDGETPU_PSM0_DEBUGCFG);
		/* Write then clear EDGETPU_PSM0_DEBUGCFG[1] to update the value. */
		edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_DEBUGCFG, 0x2 | val);
		edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_DEBUGCFG, 0x1 & val);
		etdev_err(etdev, "Recovery attempt finish\n");
	}
}

static int janeiro_lpm_up(struct edgetpu_dev *etdev)
{
	int ret;
	u32 val;

	edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_START, 1);
	ret = readl_poll_timeout(etdev->regs.mem + EDGETPU_PSM0_STATUS, val, val & 0x80, 20,
				 EDGETPU_LPM_CHANGE_TIMEOUT);
	if (ret) {
		etdev_err(etdev, "Set LPM0 failed: %d\n", ret);
		return ret;
	}
	edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM1_START, 1);
	ret = readl_poll_timeout(etdev->regs.mem + EDGETPU_PSM1_STATUS, val, val & 0x80, 20,
				 EDGETPU_LPM_CHANGE_TIMEOUT);
	if (ret) {
		etdev_err(etdev, "Set LPM1 failed: %d\n", ret);
		return ret;
	}

	edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM0_CFG, 0);
	edgetpu_dev_write_32_sync(etdev, EDGETPU_PSM1_CFG, 0);

	return 0;
}

static int get_blk_status_by_reg(struct edgetpu_mobile_platform_dev *etmdev)
{
	return readl(etmdev->pmu_status);
}

static int get_blk_status_by_acpm(struct edgetpu_mobile_platform_dev *etmdev)
{
	/* Check BLK status instead of CLK rate */
	return exynos_acpm_get_rate(TPU_ACPM_DOMAIN, 1);
}

static bool janeiro_is_block_down(struct edgetpu_dev *etdev)
{
	struct edgetpu_mobile_platform_dev *etmdev = to_mobile_dev(etdev);
	int timeout_cnt = 0;
	int curr_state;
	int (*status)(struct edgetpu_mobile_platform_dev *etmdev);

	if (etmdev->pmu_status)
		status = get_blk_status_by_reg;
	else
		status = get_blk_status_by_acpm;

	do {
		/* Delay 20us per retry till blk shutdown finished */
		usleep_range(SHUTDOWN_DELAY_US_MIN, SHUTDOWN_DELAY_US_MAX);
		curr_state = status(etmdev);
		if (!curr_state)
			return true;
		timeout_cnt++;
	} while (timeout_cnt < SHUTDOWN_MAX_DELAY_COUNT);

	return false;
}

static void janeiro_firmware_down(struct edgetpu_dev *etdev)
{
	int ret;

	ret = edgetpu_kci_shutdown(etdev->kci);
	if (ret) {
		etdev_err(etdev, "firmware shutdown failed: %d", ret);
		return;
	}
}

static int janeiro_acpm_set_rate(unsigned int id, unsigned long rate)
{
	return exynos_acpm_set_rate(id, rate);
}

int edgetpu_chip_pm_create(struct edgetpu_dev *etdev)
{
	struct edgetpu_mobile_platform_dev *etmdev = to_mobile_dev(etdev);
	struct edgetpu_mobile_platform_pwr *platform_pwr = &etmdev->platform_pwr;

	platform_pwr->lpm_up = janeiro_lpm_up;
	platform_pwr->lpm_down = janeiro_lpm_down;
	platform_pwr->is_block_down = janeiro_is_block_down;
	platform_pwr->firmware_down = janeiro_firmware_down;
	platform_pwr->acpm_set_rate = janeiro_acpm_set_rate;

	return edgetpu_mobile_pm_create(etdev);
}