From 0fffdf6ca9926243db9ca17701fcdc0a38c67d48 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 7 Nov 2014 17:25:26 +0100 Subject: [PATCH] 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 --- drivers/gpu/drm/tegra/dsi.c | 267 ++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/tegra/dsi.h | 13 +- 2 files changed, 279 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c index 66816104ba72..6646fa2adc38 100644 --- a/drivers/gpu/drm/tegra/dsi.c +++ b/drivers/gpu/drm/tegra/dsi.c @@ -993,6 +993,272 @@ static int tegra_dsi_setup_clocks(struct tegra_dsi *dsi) 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 int tegra_dsi_host_detach(struct mipi_dsi_host *host, 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 1f6ca68108d8..bad1006a5150 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 -- 2.39.5