1 // SPDX-License-Identifier: GPL-2.0
3 * NHI specific operations
5 * Copyright (C) 2019, Intel Corporation
6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
9 #include <linux/delay.h>
10 #include <linux/suspend.h>
16 /* Ice Lake specific NHI operations */
18 #define ICL_LC_MAILBOX_TIMEOUT 500 /* ms */
20 static int check_for_device(struct device *dev, void *data)
22 return tb_is_switch(dev);
25 static bool icl_nhi_is_device_connected(struct tb_nhi *nhi)
27 struct tb *tb = pci_get_drvdata(nhi->pdev);
30 ret = device_for_each_child(&tb->root_switch->dev, NULL,
35 static int icl_nhi_force_power(struct tb_nhi *nhi, bool power)
40 * The Thunderbolt host controller is present always in Ice Lake
41 * but the firmware may not be loaded and running (depending
42 * whether there is device connected and so on). Each time the
43 * controller is used we need to "Force Power" it first and wait
44 * for the firmware to indicate it is up and running. This "Force
45 * Power" is really not about actually powering on/off the
46 * controller so it is accessible even if "Force Power" is off.
48 * The actual power management happens inside shared ACPI power
49 * resources using standard ACPI methods.
51 pci_read_config_dword(nhi->pdev, VS_CAP_22, &vs_cap);
53 vs_cap &= ~VS_CAP_22_DMA_DELAY_MASK;
54 vs_cap |= 0x22 << VS_CAP_22_DMA_DELAY_SHIFT;
55 vs_cap |= VS_CAP_22_FORCE_POWER;
57 vs_cap &= ~VS_CAP_22_FORCE_POWER;
59 pci_write_config_dword(nhi->pdev, VS_CAP_22, vs_cap);
62 unsigned int retries = 10;
65 /* Wait until the firmware tells it is up and running */
67 pci_read_config_dword(nhi->pdev, VS_CAP_9, &val);
68 if (val & VS_CAP_9_FW_READY)
79 static void icl_nhi_lc_mailbox_cmd(struct tb_nhi *nhi, enum icl_lc_mailbox_cmd cmd)
83 pci_read_config_dword(nhi->pdev, VS_CAP_19, &data);
84 data = (cmd << VS_CAP_19_CMD_SHIFT) & VS_CAP_19_CMD_MASK;
85 pci_write_config_dword(nhi->pdev, VS_CAP_19, data | VS_CAP_19_VALID);
88 static int icl_nhi_lc_mailbox_cmd_complete(struct tb_nhi *nhi, int timeout)
96 end = jiffies + msecs_to_jiffies(timeout);
98 pci_read_config_dword(nhi->pdev, VS_CAP_18, &data);
99 if (data & VS_CAP_18_DONE)
102 } while (time_before(jiffies, end));
107 /* Clear the valid bit */
108 pci_write_config_dword(nhi->pdev, VS_CAP_19, 0);
112 static void icl_nhi_set_ltr(struct tb_nhi *nhi)
116 pci_read_config_dword(nhi->pdev, VS_CAP_16, &max_ltr);
118 /* Program the same value for both snoop and no-snoop */
119 ltr = max_ltr << 16 | max_ltr;
120 pci_write_config_dword(nhi->pdev, VS_CAP_15, ltr);
123 static int icl_nhi_suspend(struct tb_nhi *nhi)
127 if (icl_nhi_is_device_connected(nhi))
131 * If there is no device connected we need to perform both: a
132 * handshake through LC mailbox and force power down before
135 icl_nhi_lc_mailbox_cmd(nhi, ICL_LC_PREPARE_FOR_RESET);
136 ret = icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT);
140 return icl_nhi_force_power(nhi, false);
143 static int icl_nhi_suspend_noirq(struct tb_nhi *nhi, bool wakeup)
145 enum icl_lc_mailbox_cmd cmd;
147 if (!pm_suspend_via_firmware())
148 return icl_nhi_suspend(nhi);
150 cmd = wakeup ? ICL_LC_GO2SX : ICL_LC_GO2SX_NO_WAKE;
151 icl_nhi_lc_mailbox_cmd(nhi, cmd);
152 return icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT);
155 static int icl_nhi_resume(struct tb_nhi *nhi)
159 ret = icl_nhi_force_power(nhi, true);
163 icl_nhi_set_ltr(nhi);
167 static void icl_nhi_shutdown(struct tb_nhi *nhi)
169 icl_nhi_force_power(nhi, false);
172 const struct tb_nhi_ops icl_nhi_ops = {
173 .init = icl_nhi_resume,
174 .suspend_noirq = icl_nhi_suspend_noirq,
175 .resume_noirq = icl_nhi_resume,
176 .runtime_suspend = icl_nhi_suspend,
177 .runtime_resume = icl_nhi_resume,
178 .shutdown = icl_nhi_shutdown,