tpm/tpm_crb: implement tpm crb idle state

[linux.git] / drivers / char / tpm / tpm_crb.c

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index c8b0d91d97908f49670c4ba838ed4388ac5d7083..466d12b7fd46a9f04332f9554b47f5b3eae415f9 100644 (file)
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -19,7 +19,6 @@
 #include <linux/highmem.h>
 #include <linux/rculist.h>
 #include <linux/module.h>
-#include <linux/platform_device.h>
 #include "tpm.h"
 
 #define ACPI_SIG_TPM2 "TPM2"
@@ -35,8 +34,8 @@ enum crb_defaults {
 };
 
 enum crb_ctrl_req {
-       CRB_CTRL_REQ_GO_IDLE    = BIT(0),
-       CRB_CTRL_REQ_CMD_READY  = BIT(1),
+       CRB_CTRL_REQ_CMD_READY  = BIT(0),
+       CRB_CTRL_REQ_GO_IDLE    = BIT(1),
 };
 
 enum crb_ctrl_sts {
@@ -81,8 +80,78 @@ struct crb_priv {
        struct crb_control_area __iomem *cca;
        u8 __iomem *cmd;
        u8 __iomem *rsp;
+       u32 cmd_size;
 };
 
+/**
+ * crb_go_idle - request tpm crb device to go the idle state
+ *
+ * @dev:  crb device
+ * @priv: crb private data
+ *
+ * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
+ * The device should respond within TIMEOUT_C by clearing the bit.
+ * Anyhow, we do not wait here as a consequent CMD_READY request
+ * will be handled correctly even if idle was not completed.
+ *
+ * The function does nothing for devices with ACPI-start method.
+ *
+ * Return: 0 always
+ */
+static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
+{
+       if (priv->flags & CRB_FL_ACPI_START)
+               return 0;
+
+       iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req);
+       /* we don't really care when this settles */
+
+       return 0;
+}
+
+/**
+ * crb_cmd_ready - request tpm crb device to enter ready state
+ *
+ * @dev:  crb device
+ * @priv: crb private data
+ *
+ * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
+ * and poll till the device acknowledge it by clearing the bit.
+ * The device should respond within TIMEOUT_C.
+ *
+ * The function does nothing for devices with ACPI-start method
+ *
+ * Return: 0 on success -ETIME on timeout;
+ */
+static int __maybe_unused crb_cmd_ready(struct device *dev,
+                                       struct crb_priv *priv)
+{
+       ktime_t stop, start;
+
+       if (priv->flags & CRB_FL_ACPI_START)
+               return 0;
+
+       iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req);
+
+       start = ktime_get();
+       stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C));
+       do {
+               if (!(ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY)) {
+                       dev_dbg(dev, "cmdReady in %lld usecs\n",
+                               ktime_to_us(ktime_sub(ktime_get(), start)));
+                       return 0;
+               }
+               usleep_range(50, 100);
+       } while (ktime_before(ktime_get(), stop));
+
+       if (ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY) {
+               dev_warn(dev, "cmdReady timed out\n");
+               return -ETIME;
+       }
+
+       return 0;
+}
+
 static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
 
 static u8 crb_status(struct tpm_chip *chip)
@@ -147,11 +216,9 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
         */
        iowrite32(0, &priv->cca->cancel);
 
-       if (len > ioread32(&priv->cca->cmd_size)) {
-               dev_err(&chip->dev,
-                       "invalid command count value %x %zx\n",
-                       (unsigned int) len,
-                       (size_t) ioread32(&priv->cca->cmd_size));
+       if (len > priv->cmd_size) {
+               dev_err(&chip->dev, "invalid command count value %zd %d\n",
+                       len, priv->cmd_size);
                return -E2BIG;
        }
 
@@ -161,7 +228,7 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
        wmb();
 
        if (priv->flags & CRB_FL_CRB_START)
-               iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start);
+               iowrite32(CRB_START_INVOKE, &priv->cca->start);
 
        if (priv->flags & CRB_FL_ACPI_START)
                rc = crb_do_acpi_start(chip);
@@ -173,7 +240,7 @@ static void crb_cancel(struct tpm_chip *chip)
 {
        struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 
-       iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel);
+       iowrite32(CRB_CANCEL_INVOKE, &priv->cca->cancel);
 
        if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
                dev_err(&chip->dev, "ACPI Start failed\n");
@@ -265,8 +332,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
        acpi_dev_free_resource_list(&resources);
 
        if (resource_type(&io_res) != IORESOURCE_MEM) {
-               dev_err(dev,
-                       FW_BUG "TPM2 ACPI table does not define a memory resource\n");
+               dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
                return -EINVAL;
        }
 
@@ -302,6 +368,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
                dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
                return -EINVAL;
        }
+       priv->cmd_size = cmd_size;
 
        priv->rsp = priv->cmd;
        return 0;