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![Mika Westerberg](/assets/img/avatar_default.png)
The read is not needed as we overwrite the returned value in the next
line anyway so drop it.
Fixes: 3cdb9446a1
("thunderbolt: Add support for Intel Ice Lake")
Reported-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
178 lines
4.1 KiB
C
178 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* NHI specific operations
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*
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* Copyright (C) 2019, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*/
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#include <linux/delay.h>
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#include <linux/suspend.h>
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#include "nhi.h"
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#include "nhi_regs.h"
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#include "tb.h"
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/* Ice Lake specific NHI operations */
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#define ICL_LC_MAILBOX_TIMEOUT 500 /* ms */
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static int check_for_device(struct device *dev, void *data)
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{
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return tb_is_switch(dev);
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}
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static bool icl_nhi_is_device_connected(struct tb_nhi *nhi)
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{
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struct tb *tb = pci_get_drvdata(nhi->pdev);
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int ret;
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ret = device_for_each_child(&tb->root_switch->dev, NULL,
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check_for_device);
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return ret > 0;
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}
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static int icl_nhi_force_power(struct tb_nhi *nhi, bool power)
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{
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u32 vs_cap;
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/*
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* The Thunderbolt host controller is present always in Ice Lake
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* but the firmware may not be loaded and running (depending
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* whether there is device connected and so on). Each time the
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* controller is used we need to "Force Power" it first and wait
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* for the firmware to indicate it is up and running. This "Force
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* Power" is really not about actually powering on/off the
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* controller so it is accessible even if "Force Power" is off.
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*
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* The actual power management happens inside shared ACPI power
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* resources using standard ACPI methods.
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*/
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pci_read_config_dword(nhi->pdev, VS_CAP_22, &vs_cap);
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if (power) {
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vs_cap &= ~VS_CAP_22_DMA_DELAY_MASK;
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vs_cap |= 0x22 << VS_CAP_22_DMA_DELAY_SHIFT;
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vs_cap |= VS_CAP_22_FORCE_POWER;
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} else {
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vs_cap &= ~VS_CAP_22_FORCE_POWER;
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}
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pci_write_config_dword(nhi->pdev, VS_CAP_22, vs_cap);
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if (power) {
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unsigned int retries = 10;
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u32 val;
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/* Wait until the firmware tells it is up and running */
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do {
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pci_read_config_dword(nhi->pdev, VS_CAP_9, &val);
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if (val & VS_CAP_9_FW_READY)
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return 0;
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msleep(250);
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} while (--retries);
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return -ETIMEDOUT;
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}
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return 0;
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}
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static void icl_nhi_lc_mailbox_cmd(struct tb_nhi *nhi, enum icl_lc_mailbox_cmd cmd)
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{
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u32 data;
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data = (cmd << VS_CAP_19_CMD_SHIFT) & VS_CAP_19_CMD_MASK;
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pci_write_config_dword(nhi->pdev, VS_CAP_19, data | VS_CAP_19_VALID);
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}
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static int icl_nhi_lc_mailbox_cmd_complete(struct tb_nhi *nhi, int timeout)
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{
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unsigned long end;
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u32 data;
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if (!timeout)
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goto clear;
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end = jiffies + msecs_to_jiffies(timeout);
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do {
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pci_read_config_dword(nhi->pdev, VS_CAP_18, &data);
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if (data & VS_CAP_18_DONE)
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goto clear;
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msleep(100);
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} while (time_before(jiffies, end));
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return -ETIMEDOUT;
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clear:
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/* Clear the valid bit */
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pci_write_config_dword(nhi->pdev, VS_CAP_19, 0);
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return 0;
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}
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static void icl_nhi_set_ltr(struct tb_nhi *nhi)
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{
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u32 max_ltr, ltr;
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pci_read_config_dword(nhi->pdev, VS_CAP_16, &max_ltr);
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max_ltr &= 0xffff;
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/* Program the same value for both snoop and no-snoop */
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ltr = max_ltr << 16 | max_ltr;
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pci_write_config_dword(nhi->pdev, VS_CAP_15, ltr);
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}
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static int icl_nhi_suspend(struct tb_nhi *nhi)
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{
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int ret;
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if (icl_nhi_is_device_connected(nhi))
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return 0;
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/*
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* If there is no device connected we need to perform both: a
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* handshake through LC mailbox and force power down before
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* entering D3.
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*/
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icl_nhi_lc_mailbox_cmd(nhi, ICL_LC_PREPARE_FOR_RESET);
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ret = icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT);
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if (ret)
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return ret;
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return icl_nhi_force_power(nhi, false);
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}
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static int icl_nhi_suspend_noirq(struct tb_nhi *nhi, bool wakeup)
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{
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enum icl_lc_mailbox_cmd cmd;
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if (!pm_suspend_via_firmware())
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return icl_nhi_suspend(nhi);
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cmd = wakeup ? ICL_LC_GO2SX : ICL_LC_GO2SX_NO_WAKE;
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icl_nhi_lc_mailbox_cmd(nhi, cmd);
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return icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT);
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}
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static int icl_nhi_resume(struct tb_nhi *nhi)
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{
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int ret;
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ret = icl_nhi_force_power(nhi, true);
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if (ret)
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return ret;
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icl_nhi_set_ltr(nhi);
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return 0;
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}
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static void icl_nhi_shutdown(struct tb_nhi *nhi)
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{
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icl_nhi_force_power(nhi, false);
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}
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const struct tb_nhi_ops icl_nhi_ops = {
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.init = icl_nhi_resume,
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.suspend_noirq = icl_nhi_suspend_noirq,
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.resume_noirq = icl_nhi_resume,
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.runtime_suspend = icl_nhi_suspend,
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.runtime_resume = icl_nhi_resume,
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.shutdown = icl_nhi_shutdown,
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};
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