diff options
Diffstat (limited to 'drivers/thunderbolt/nhi_ops.c')
| -rw-r--r-- | drivers/thunderbolt/nhi_ops.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/thunderbolt/nhi_ops.c b/drivers/thunderbolt/nhi_ops.c new file mode 100644 index 000000000000..61cd09cef943 --- /dev/null +++ b/drivers/thunderbolt/nhi_ops.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NHI specific operations + * + * Copyright (C) 2019, Intel Corporation + * Author: Mika Westerberg <mika.westerberg@linux.intel.com> + */ + +#include <linux/delay.h> +#include <linux/suspend.h> + +#include "nhi.h" +#include "nhi_regs.h" +#include "tb.h" + +/* Ice Lake specific NHI operations */ + +#define ICL_LC_MAILBOX_TIMEOUT 500 /* ms */ + +static int check_for_device(struct device *dev, void *data) +{ + return tb_is_switch(dev); +} + +static bool icl_nhi_is_device_connected(struct tb_nhi *nhi) +{ + struct tb *tb = pci_get_drvdata(nhi->pdev); + int ret; + + ret = device_for_each_child(&tb->root_switch->dev, NULL, + check_for_device); + return ret > 0; +} + +static int icl_nhi_force_power(struct tb_nhi *nhi, bool power) +{ + u32 vs_cap; + + /* + * The Thunderbolt host controller is present always in Ice Lake + * but the firmware may not be loaded and running (depending + * whether there is device connected and so on). Each time the + * controller is used we need to "Force Power" it first and wait + * for the firmware to indicate it is up and running. This "Force + * Power" is really not about actually powering on/off the + * controller so it is accessible even if "Force Power" is off. + * + * The actual power management happens inside shared ACPI power + * resources using standard ACPI methods. + */ + pci_read_config_dword(nhi->pdev, VS_CAP_22, &vs_cap); + if (power) { + vs_cap &= ~VS_CAP_22_DMA_DELAY_MASK; + vs_cap |= 0x22 << VS_CAP_22_DMA_DELAY_SHIFT; + vs_cap |= VS_CAP_22_FORCE_POWER; + } else { + vs_cap &= ~VS_CAP_22_FORCE_POWER; + } + pci_write_config_dword(nhi->pdev, VS_CAP_22, vs_cap); + + if (power) { + unsigned int retries = 10; + u32 val; + + /* Wait until the firmware tells it is up and running */ + do { + pci_read_config_dword(nhi->pdev, VS_CAP_9, &val); + if (val & VS_CAP_9_FW_READY) + return 0; + msleep(250); + } while (--retries); + + return -ETIMEDOUT; + } + + return 0; +} + +static void icl_nhi_lc_mailbox_cmd(struct tb_nhi *nhi, enum icl_lc_mailbox_cmd cmd) +{ + u32 data; + + pci_read_config_dword(nhi->pdev, VS_CAP_19, &data); + data = (cmd << VS_CAP_19_CMD_SHIFT) & VS_CAP_19_CMD_MASK; + pci_write_config_dword(nhi->pdev, VS_CAP_19, data | VS_CAP_19_VALID); +} + +static int icl_nhi_lc_mailbox_cmd_complete(struct tb_nhi *nhi, int timeout) +{ + unsigned long end; + u32 data; + + if (!timeout) + goto clear; + + end = jiffies + msecs_to_jiffies(timeout); + do { + pci_read_config_dword(nhi->pdev, VS_CAP_18, &data); + if (data & VS_CAP_18_DONE) + goto clear; + msleep(100); + } while (time_before(jiffies, end)); + + return -ETIMEDOUT; + +clear: + /* Clear the valid bit */ + pci_write_config_dword(nhi->pdev, VS_CAP_19, 0); + return 0; +} + +static void icl_nhi_set_ltr(struct tb_nhi *nhi) +{ + u32 max_ltr, ltr; + + pci_read_config_dword(nhi->pdev, VS_CAP_16, &max_ltr); + max_ltr &= 0xffff; + /* Program the same value for both snoop and no-snoop */ + ltr = max_ltr << 16 | max_ltr; + pci_write_config_dword(nhi->pdev, VS_CAP_15, ltr); +} + +static int icl_nhi_suspend(struct tb_nhi *nhi) +{ + int ret; + + if (icl_nhi_is_device_connected(nhi)) + return 0; + + /* + * If there is no device connected we need to perform both: a + * handshake through LC mailbox and force power down before + * entering D3. + */ + icl_nhi_lc_mailbox_cmd(nhi, ICL_LC_PREPARE_FOR_RESET); + ret = icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT); + if (ret) + return ret; + + return icl_nhi_force_power(nhi, false); +} + +static int icl_nhi_suspend_noirq(struct tb_nhi *nhi, bool wakeup) +{ + enum icl_lc_mailbox_cmd cmd; + + if (!pm_suspend_via_firmware()) + return icl_nhi_suspend(nhi); + + cmd = wakeup ? ICL_LC_GO2SX : ICL_LC_GO2SX_NO_WAKE; + icl_nhi_lc_mailbox_cmd(nhi, cmd); + return icl_nhi_lc_mailbox_cmd_complete(nhi, ICL_LC_MAILBOX_TIMEOUT); +} + +static int icl_nhi_resume(struct tb_nhi *nhi) +{ + int ret; + + ret = icl_nhi_force_power(nhi, true); + if (ret) + return ret; + + icl_nhi_set_ltr(nhi); + return 0; +} + +static void icl_nhi_shutdown(struct tb_nhi *nhi) +{ + icl_nhi_force_power(nhi, false); +} + +const struct tb_nhi_ops icl_nhi_ops = { + .init = icl_nhi_resume, + .suspend_noirq = icl_nhi_suspend_noirq, + .resume_noirq = icl_nhi_resume, + .runtime_suspend = icl_nhi_suspend, + .runtime_resume = icl_nhi_resume, + .shutdown = icl_nhi_shutdown, +}; |