drm/tegra: dsi: Implement host transfers
Add support for sending MIPI DSI command packets from the host to a
peripheral. This is required for panels that need configuration before
they accept video data.
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index 6681610..6646fa2 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -993,6 +993,272 @@
return 0;
}
+static const char * const error_report[16] = {
+ "SoT Error",
+ "SoT Sync Error",
+ "EoT Sync Error",
+ "Escape Mode Entry Command Error",
+ "Low-Power Transmit Sync Error",
+ "Peripheral Timeout Error",
+ "False Control Error",
+ "Contention Detected",
+ "ECC Error, single-bit",
+ "ECC Error, multi-bit",
+ "Checksum Error",
+ "DSI Data Type Not Recognized",
+ "DSI VC ID Invalid",
+ "Invalid Transmission Length",
+ "Reserved",
+ "DSI Protocol Violation",
+};
+
+static ssize_t tegra_dsi_read_response(struct tegra_dsi *dsi,
+ const struct mipi_dsi_msg *msg,
+ size_t count)
+{
+ u8 *rx = msg->rx_buf;
+ unsigned int i, j, k;
+ size_t size = 0;
+ u16 errors;
+ u32 value;
+
+ /* read and parse packet header */
+ value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+
+ switch (value & 0x3f) {
+ case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT:
+ errors = (value >> 8) & 0xffff;
+ dev_dbg(dsi->dev, "Acknowledge and error report: %04x\n",
+ errors);
+ for (i = 0; i < ARRAY_SIZE(error_report); i++)
+ if (errors & BIT(i))
+ dev_dbg(dsi->dev, " %2u: %s\n", i,
+ error_report[i]);
+ break;
+
+ case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE:
+ rx[0] = (value >> 8) & 0xff;
+ size = 1;
+ break;
+
+ case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE:
+ rx[0] = (value >> 8) & 0xff;
+ rx[1] = (value >> 16) & 0xff;
+ size = 2;
+ break;
+
+ case MIPI_DSI_RX_DCS_LONG_READ_RESPONSE:
+ size = ((value >> 8) & 0xff00) | ((value >> 8) & 0xff);
+ break;
+
+ case MIPI_DSI_RX_GENERIC_LONG_READ_RESPONSE:
+ size = ((value >> 8) & 0xff00) | ((value >> 8) & 0xff);
+ break;
+
+ default:
+ dev_err(dsi->dev, "unhandled response type: %02x\n",
+ value & 0x3f);
+ return -EPROTO;
+ }
+
+ size = min(size, msg->rx_len);
+
+ if (msg->rx_buf && size > 0) {
+ for (i = 0, j = 0; i < count - 1; i++, j += 4) {
+ u8 *rx = msg->rx_buf + j;
+
+ value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+
+ for (k = 0; k < 4 && (j + k) < msg->rx_len; k++)
+ rx[j + k] = (value >> (k << 3)) & 0xff;
+ }
+ }
+
+ return size;
+}
+
+static int tegra_dsi_transmit(struct tegra_dsi *dsi, unsigned long timeout)
+{
+ tegra_dsi_writel(dsi, DSI_TRIGGER_HOST, DSI_TRIGGER);
+
+ timeout = jiffies + msecs_to_jiffies(timeout);
+
+ while (time_before(jiffies, timeout)) {
+ u32 value = tegra_dsi_readl(dsi, DSI_TRIGGER);
+ if ((value & DSI_TRIGGER_HOST) == 0)
+ return 0;
+
+ usleep_range(1000, 2000);
+ }
+
+ DRM_DEBUG_KMS("timeout waiting for transmission to complete\n");
+ return -ETIMEDOUT;
+}
+
+static int tegra_dsi_wait_for_response(struct tegra_dsi *dsi,
+ unsigned long timeout)
+{
+ timeout = jiffies + msecs_to_jiffies(250);
+
+ while (time_before(jiffies, timeout)) {
+ u32 value = tegra_dsi_readl(dsi, DSI_STATUS);
+ u8 count = value & 0x1f;
+
+ if (count > 0)
+ return count;
+
+ usleep_range(1000, 2000);
+ }
+
+ DRM_DEBUG_KMS("peripheral returned no data\n");
+ return -ETIMEDOUT;
+}
+
+static void tegra_dsi_writesl(struct tegra_dsi *dsi, unsigned long offset,
+ const void *buffer, size_t size)
+{
+ const u8 *buf = buffer;
+ size_t i, j;
+ u32 value;
+
+ for (j = 0; j < size; j += 4) {
+ value = 0;
+
+ for (i = 0; i < 4 && j + i < size; i++)
+ value |= buf[j + i] << (i << 3);
+
+ tegra_dsi_writel(dsi, value, DSI_WR_DATA);
+ }
+}
+
+static ssize_t tegra_dsi_host_transfer(struct mipi_dsi_host *host,
+ const struct mipi_dsi_msg *msg)
+{
+ struct tegra_dsi *dsi = host_to_tegra(host);
+ struct mipi_dsi_packet packet;
+ const u8 *header;
+ size_t count;
+ ssize_t err;
+ u32 value;
+
+ err = mipi_dsi_create_packet(&packet, msg);
+ if (err < 0)
+ return err;
+
+ header = packet.header;
+
+ /* maximum FIFO depth is 1920 words */
+ if (packet.size > dsi->video_fifo_depth * 4)
+ return -ENOSPC;
+
+ /* reset underflow/overflow flags */
+ value = tegra_dsi_readl(dsi, DSI_STATUS);
+ if (value & (DSI_STATUS_UNDERFLOW | DSI_STATUS_OVERFLOW)) {
+ value = DSI_HOST_CONTROL_FIFO_RESET;
+ tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+ usleep_range(10, 20);
+ }
+
+ value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+ value |= DSI_POWER_CONTROL_ENABLE;
+ tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+ usleep_range(5000, 10000);
+
+ value = DSI_HOST_CONTROL_CRC_RESET | DSI_HOST_CONTROL_TX_TRIG_HOST |
+ DSI_HOST_CONTROL_CS | DSI_HOST_CONTROL_ECC;
+
+ if ((msg->flags & MIPI_DSI_MSG_USE_LPM) == 0)
+ value |= DSI_HOST_CONTROL_HS;
+
+ /*
+ * The host FIFO has a maximum of 64 words, so larger transmissions
+ * need to use the video FIFO.
+ */
+ if (packet.size > dsi->host_fifo_depth * 4)
+ value |= DSI_HOST_CONTROL_FIFO_SEL;
+
+ tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+
+ /*
+ * For reads and messages with explicitly requested ACK, generate a
+ * BTA sequence after the transmission of the packet.
+ */
+ if ((msg->flags & MIPI_DSI_MSG_REQ_ACK) ||
+ (msg->rx_buf && msg->rx_len > 0)) {
+ value = tegra_dsi_readl(dsi, DSI_HOST_CONTROL);
+ value |= DSI_HOST_CONTROL_PKT_BTA;
+ tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+ }
+
+ value = DSI_CONTROL_LANES(0) | DSI_CONTROL_HOST_ENABLE;
+ tegra_dsi_writel(dsi, value, DSI_CONTROL);
+
+ /* write packet header, ECC is generated by hardware */
+ value = header[2] << 16 | header[1] << 8 | header[0];
+ tegra_dsi_writel(dsi, value, DSI_WR_DATA);
+
+ /* write payload (if any) */
+ if (packet.payload_length > 0)
+ tegra_dsi_writesl(dsi, DSI_WR_DATA, packet.payload,
+ packet.payload_length);
+
+ err = tegra_dsi_transmit(dsi, 250);
+ if (err < 0)
+ return err;
+
+ if ((msg->flags & MIPI_DSI_MSG_REQ_ACK) ||
+ (msg->rx_buf && msg->rx_len > 0)) {
+ err = tegra_dsi_wait_for_response(dsi, 250);
+ if (err < 0)
+ return err;
+
+ count = err;
+
+ value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+ switch (value) {
+ case 0x84:
+ /*
+ dev_dbg(dsi->dev, "ACK\n");
+ */
+ break;
+
+ case 0x87:
+ /*
+ dev_dbg(dsi->dev, "ESCAPE\n");
+ */
+ break;
+
+ default:
+ dev_err(dsi->dev, "unknown status: %08x\n", value);
+ break;
+ }
+
+ if (count > 1) {
+ err = tegra_dsi_read_response(dsi, msg, count);
+ if (err < 0)
+ dev_err(dsi->dev,
+ "failed to parse response: %zd\n",
+ err);
+ else {
+ /*
+ * For read commands, return the number of
+ * bytes returned by the peripheral.
+ */
+ count = err;
+ }
+ }
+ } else {
+ /*
+ * For write commands, we have transmitted the 4-byte header
+ * plus the variable-length payload.
+ */
+ count = 4 + packet.payload_length;
+ }
+
+ return count;
+}
+
static int tegra_dsi_ganged_setup(struct tegra_dsi *dsi)
{
struct clk *parent;
@@ -1069,6 +1335,7 @@
static const struct mipi_dsi_host_ops tegra_dsi_host_ops = {
.attach = tegra_dsi_host_attach,
.detach = tegra_dsi_host_detach,
+ .transfer = tegra_dsi_host_transfer,
};
static int tegra_dsi_ganged_probe(struct tegra_dsi *dsi)
diff --git a/drivers/gpu/drm/tegra/dsi.h b/drivers/gpu/drm/tegra/dsi.h
index 1f6ca68..bad1006 100644
--- a/drivers/gpu/drm/tegra/dsi.h
+++ b/drivers/gpu/drm/tegra/dsi.h
@@ -21,9 +21,16 @@
#define DSI_INT_STATUS 0x0d
#define DSI_INT_MASK 0x0e
#define DSI_HOST_CONTROL 0x0f
+#define DSI_HOST_CONTROL_FIFO_RESET (1 << 21)
+#define DSI_HOST_CONTROL_CRC_RESET (1 << 20)
+#define DSI_HOST_CONTROL_TX_TRIG_SOL (0 << 12)
+#define DSI_HOST_CONTROL_TX_TRIG_FIFO (1 << 12)
+#define DSI_HOST_CONTROL_TX_TRIG_HOST (2 << 12)
#define DSI_HOST_CONTROL_RAW (1 << 6)
#define DSI_HOST_CONTROL_HS (1 << 5)
-#define DSI_HOST_CONTROL_BTA (1 << 2)
+#define DSI_HOST_CONTROL_FIFO_SEL (1 << 4)
+#define DSI_HOST_CONTROL_IMM_BTA (1 << 3)
+#define DSI_HOST_CONTROL_PKT_BTA (1 << 2)
#define DSI_HOST_CONTROL_CS (1 << 1)
#define DSI_HOST_CONTROL_ECC (1 << 0)
#define DSI_CONTROL 0x10
@@ -39,9 +46,13 @@
#define DSI_SOL_DELAY 0x11
#define DSI_MAX_THRESHOLD 0x12
#define DSI_TRIGGER 0x13
+#define DSI_TRIGGER_HOST (1 << 1)
+#define DSI_TRIGGER_VIDEO (1 << 0)
#define DSI_TX_CRC 0x14
#define DSI_STATUS 0x15
#define DSI_STATUS_IDLE (1 << 10)
+#define DSI_STATUS_UNDERFLOW (1 << 9)
+#define DSI_STATUS_OVERFLOW (1 << 8)
#define DSI_INIT_SEQ_CONTROL 0x1a
#define DSI_INIT_SEQ_DATA_0 0x1b
#define DSI_INIT_SEQ_DATA_1 0x1c
