To support Host to read data from Peripheral after
a DCS read command is sent over DSI.
v1: initial version.
v2:
- adding error message when failing to place BTA.
- returning byte number instead of 0 for the read
function dsi_read_pkt_payld().
v3: fixing coding style warning.
v4:
- correcting the data type of returning data for
the read function dsi_read_pkt_payld().
v5: adding change history as part of commit messages.
v6: according to the review comments from Jani,
- drop the commented out variable "hdr_data".
- use int insteaf of u8 as the data type of the loop
variable i.
- use intel_de_rmw() for read-modify-write.
- add new function place_bta_request() to keep
payload receive function clean.
- explicitly clear the READ_UNLOADS_DW bit of
DSI_CMD_RXCTL before reading receive payload.
- use two loops to copy received data.
- remove the unrelated change from this patch,
which is made to gen11_dsi_setup_timeouts().
- drop the comment in gen11_dsi_host_transfer().
- change the condition to call the payload
receive function in gen11_dsi_host_transfer().
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
Cc: Lee Shawn C <shawn.c.lee@xxxxxxxxx>
Signed-off-by: William Tseng <william.tseng@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/icl_dsi.c | 76 ++++++++++++++++++++-
drivers/gpu/drm/i915/display/icl_dsi_regs.h | 13 ++++
2 files changed, 86 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c
index 19bf717fd4cb..edf20016af91 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi.c
+++ b/drivers/gpu/drm/i915/display/icl_dsi.c
@@ -201,6 +201,75 @@ static int dsi_send_pkt_hdr(struct intel_dsi_host *host,
return 0;
}
+static bool place_bta_request(struct intel_dsi_host *host)
+{
+ struct intel_dsi *intel_dsi = host->intel_dsi;
+ struct drm_i915_private *dev_priv = to_i915(intel_dsi->base.base.dev);
+ enum transcoder dsi_trans = dsi_port_to_transcoder(host->port);
+
+ /* step2a(i): specify Turn-Around timeout */
+ intel_de_rmw(dev_priv, DSI_TA_TO(dsi_trans), TA_TIMEOUT_VALUE_MASK,
+ TA_TIMEOUT_VALUE(intel_dsi->turn_arnd_val));
+
+ /* step2a(ii): specify maximum allowed time */
+ intel_de_rmw(dev_priv, DSI_LPRX_HOST_TO(dsi_trans), ~LPRX_TIMEOUT_VALUE_MASK,
+ LPRX_TIMEOUT_VALUE(intel_dsi->lp_rx_timeout));
+
+ /* check if header credit available */
+ if (!wait_for_header_credits(dev_priv, dsi_trans, 1)) {
+ drm_err(&dev_priv->drm, "not ready to recive payload\n");
+ return false;
+ }
+
+ /* place BTA request */
+ intel_de_rmw(dev_priv, DSI_LP_MSG(dsi_trans), LINK_BTA, LINK_BTA);
+
+ return true;
+}
+
+static int dsi_read_pkt_payld(struct intel_dsi_host *host,
+ u8 *rx_buf, size_t rx_len)
+{
+ struct intel_dsi *intel_dsi = host->intel_dsi;
+ struct drm_i915_private *dev_priv = to_i915(intel_dsi->base.base.dev);
+ enum transcoder dsi_trans = dsi_port_to_transcoder(host->port);
+ u32 tmp, payld_data;
+ u32 payld_dw;
+ int i, j;
+
+ if (rx_len <= 0)
+ return 0;
+
+ /* do not unload receive queue */
+ tmp = intel_de_read(dev_priv, DSI_CMD_RXCTL(dsi_trans));
+ tmp &= ~READ_UNLOADS_DW;
+ intel_de_write(dev_priv, DSI_CMD_RXCTL(dsi_trans), tmp);
+
+ /* step2: place a BTA request */
+ if (!place_bta_request(host))
+ return -EBUSY;
+
+ /* step4a: wait and read payload */
+ if (wait_for_us(((intel_de_read(dev_priv, DSI_CMD_RXCTL(dsi_trans)) &
+ NUMBER_RX_PLOAD_DW_MASK) >> NUMBER_RX_PLOAD_DW_SHIFT) > 0, 100000)) {
+ drm_err(&dev_priv->drm, "DSI fails to receive payload\n");
+ return -EBUSY;
+ }
+
+ tmp = intel_de_read(dev_priv, DSI_CMD_RXCTL(dsi_trans));
+ payld_dw = (tmp & NUMBER_RX_PLOAD_DW_MASK) >> NUMBER_RX_PLOAD_DW_SHIFT;
+
+ for (i = 0; i < payld_dw; i++) {
+
+ payld_data = intel_de_read(dev_priv, DSI_CMD_RXPYLD(dsi_trans));
+
+ for (j = 0; j < min_t(u32, rx_len - (i * 4), 4); j++)
+ *(rx_buf + (i * 4 + j)) = (payld_data >> 8 * j) & 0xff;
+ }
+
+ return ((i - 1) * 4 + j);
+}
+
void icl_dsi_frame_update(struct intel_crtc_state *crtc_state)
{
struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
@@ -1837,9 +1906,10 @@ static ssize_t gen11_dsi_host_transfer(struct mipi_dsi_host *host,
if (ret < 0)
return ret;
- //TODO: add payload receive code if needed
-
- ret = sizeof(dsi_pkt.header) + dsi_pkt.payload_length;
+ if (msg->rx_buf)
+ ret = dsi_read_pkt_payld(intel_dsi_host, msg->rx_buf, msg->rx_len);
+ else
+ ret = sizeof(dsi_pkt.header) + dsi_pkt.payload_length;
return ret;
}
diff --git a/drivers/gpu/drm/i915/display/icl_dsi_regs.h b/drivers/gpu/drm/i915/display/icl_dsi_regs.h
index f78f28b8dd94..a77a49b42d60 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi_regs.h
+++ b/drivers/gpu/drm/i915/display/icl_dsi_regs.h
@@ -251,6 +251,18 @@
#define NUMBER_RX_PLOAD_DW_MASK (0xff << 0)
#define NUMBER_RX_PLOAD_DW_SHIFT 0
+#define _DSI_CMD_RXHDR_0 0x6b0e0
+#define _DSI_CMD_RXHDR_1 0x6b8e0
+#define DSI_CMD_RXHDR(tc) _MMIO_DSI(tc, \
+ _DSI_CMD_RXHDR_0,\
+ _DSI_CMD_RXHDR_1)
+
+#define _DSI_CMD_RXPYLD_0 0x6b0e4
+#define _DSI_CMD_RXPYLD_1 0x6b8e4
+#define DSI_CMD_RXPYLD(tc) _MMIO_DSI(tc, \
+ _DSI_CMD_RXPYLD_0,\
+ _DSI_CMD_RXPYLD_1)
+
#define _DSI_CMD_TXCTL_0 0x6b0d0
#define _DSI_CMD_TXCTL_1 0x6b8d0
#define DSI_CMD_TXCTL(tc) _MMIO_DSI(tc, \
@@ -294,6 +306,7 @@
#define LPTX_IN_PROGRESS (1 << 17)
#define LINK_IN_ULPS (1 << 16)
#define LINK_ULPS_TYPE_LP11 (1 << 8)
+#define LINK_BTA (1 << 1)
#define LINK_ENTER_ULPS (1 << 0)
/* DSI timeout registers */
--
2.17.1
