Hi Hugo, Thanks for the patch.
For some reason, your cover letter is not showing link to this patch [1] https://lore.kernel.org/all/20250520164034.3453315-1-h...@hugovil.com/ > -----Original Message----- > From: Hugo Villeneuve <h...@hugovil.com> > Sent: 20 May 2025 18:11 > Subject: [PATCH 1/2] drm: rcar-du: rzg2l_mipi_dsi: Implement host transfers rcar-du->rz-du > > From: Hugo Villeneuve <hvillene...@dimonoff.com> > > 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. > > Based on Renesas Linux kernel v5.10 repos [1]. > > Link: https://github.com/renesas-rz/rz_linux-cip.git > Cc: Biju Das <biju.das...@bp.renesas.com> > Cc: Chris Brandt <chris.bra...@renesas.com> > Signed-off-by: Hugo Villeneuve <hvillene...@dimonoff.com> > --- > .../gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 174 ++++++++++++++++++ > .../drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h | 56 ++++++ > 2 files changed, 230 insertions(+) > > diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > b/drivers/gpu/drm/renesas/rz- > du/rzg2l_mipi_dsi.c > index dc6ab012cdb69..77d3a31ff8e35 100644 > --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c > @@ -6,6 +6,7 @@ > */ > #include <linux/clk.h> > #include <linux/delay.h> > +#include <linux/dma-mapping.h> > #include <linux/io.h> > #include <linux/iopoll.h> > #include <linux/module.h> > @@ -23,9 +24,12 @@ > #include <drm/drm_of.h> > #include <drm/drm_panel.h> > #include <drm/drm_probe_helper.h> > +#include <video/mipi_display.h> > > #include "rzg2l_mipi_dsi_regs.h" > > +#define RZG2L_DCS_BUF_SIZE 128 /* Maximum DCS buffer size in external > memory. */ > + > struct rzg2l_mipi_dsi { > struct device *dev; > void __iomem *mmio; > @@ -44,6 +48,10 @@ struct rzg2l_mipi_dsi { > unsigned int num_data_lanes; > unsigned int lanes; > unsigned long mode_flags; > + > + /* DCS buffer pointers when using external memory. */ > + dma_addr_t dcs_buf_phys; > + u8 *dcs_buf_virt; > }; > > static inline struct rzg2l_mipi_dsi * > @@ -651,9 +659,168 @@ static int rzg2l_mipi_dsi_host_detach(struct > mipi_dsi_host *host, > return 0; > } > > +static ssize_t rzg2l_mipi_dsi_read_response(struct rzg2l_mipi_dsi *dsi, > + const struct mipi_dsi_msg *msg) { > + u8 *msg_rx = msg->rx_buf; > + u16 size; > + u8 datatype; > + u32 result; Please arrange the variables in reverse xmas tree fashion. > + > + result = rzg2l_mipi_dsi_link_read(dsi, RXRSS0R); > + if (result & RXRSS0R_RXPKTDFAIL) { > + dev_err(dsi->dev, "packet rx data did not save correctly\n"); > + return -EPROTO; > + } > + > + if (result & RXRSS0R_RXFAIL) { > + dev_err(dsi->dev, "packet rx failure\n"); > + return -EPROTO; > + } > + > + if (!(result & RXRSS0R_RXSUC)) > + return -EPROTO; > + > + datatype = FIELD_GET(RXRSS0R_DT, result); > + > + switch (datatype) { > + case 0: > + dev_dbg(dsi->dev, "ACK\n"); > + return 0; > + case MIPI_DSI_RX_END_OF_TRANSMISSION: > + dev_dbg(dsi->dev, "EoTp\n"); > + return 0; > + case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT: > + dev_dbg(dsi->dev, "Acknowledge and error report: $%02x%02x\n", > + (u8)FIELD_GET(RXRSS0R_DATA1, result), > + (u8)FIELD_GET(RXRSS0R_DATA0, result)); > + return 0; > + case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE: > + case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_1BYTE: > + msg_rx[0] = FIELD_GET(RXRSS0R_DATA0, result); > + return 1; > + case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE: > + case MIPI_DSI_RX_GENERIC_SHORT_READ_RESPONSE_2BYTE: > + msg_rx[0] = FIELD_GET(RXRSS0R_DATA0, result); > + msg_rx[1] = FIELD_GET(RXRSS0R_DATA1, result); > + return 2; > + case MIPI_DSI_RX_GENERIC_LONG_READ_RESPONSE: > + case MIPI_DSI_RX_DCS_LONG_READ_RESPONSE: > + size = FIELD_GET(RXRSS0R_WC, result); > + > + if (size > msg->rx_len) { > + dev_err(dsi->dev, "rx buffer too small"); > + return -ENOSPC; > + } > + > + memcpy(msg_rx, dsi->dcs_buf_virt, size); > + return size; > + default: > + dev_err(dsi->dev, "unhandled response type: %02x\n", datatype); > + return -EPROTO; > + } > +} > + > +static ssize_t rzg2l_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > + const struct mipi_dsi_msg *msg) { > + struct rzg2l_mipi_dsi *dsi = host_to_rzg2l_mipi_dsi(host); > + struct mipi_dsi_packet packet; > + bool need_bta; > + u32 value; > + int ret; > + > + ret = mipi_dsi_create_packet(&packet, msg); > + if (ret < 0) > + return ret; > + > + /* Terminate operation after this descriptor is finished */ > + value = SQCH0DSC0AR_NXACT_TERM; > + > + if (msg->flags & MIPI_DSI_MSG_REQ_ACK) { > + need_bta = true; /* Message with explicitly requested ACK */ > + value |= FIELD_PREP(SQCH0DSC0AR_BTA, SQCH0DSC0AR_BTA_NON_READ); > + } else if (msg->rx_buf && msg->rx_len > 0) { > + need_bta = true; /* Read request */ > + value |= FIELD_PREP(SQCH0DSC0AR_BTA, SQCH0DSC0AR_BTA_READ); > + } else { > + need_bta = false; > + value |= FIELD_PREP(SQCH0DSC0AR_BTA, SQCH0DSC0AR_BTA_NONE); > + } > + > + /* Set transmission speed */ > + if (msg->flags & MIPI_DSI_MSG_USE_LPM) > + value |= SQCH0DSC0AR_SPD_LOW; > + else > + value |= SQCH0DSC0AR_SPD_HIGH; > + > + /* Write TX packet header */ > + value |= FIELD_PREP(SQCH0DSC0AR_DT, packet.header[0]) | > + FIELD_PREP(SQCH0DSC0AR_DATA0, packet.header[1]) | > + FIELD_PREP(SQCH0DSC0AR_DATA1, packet.header[2]); > + > + if (mipi_dsi_packet_format_is_long(msg->type)) { > + value |= SQCH0DSC0AR_FMT_LONG; > + > + if (packet.payload_length > RZG2L_DCS_BUF_SIZE) { > + dev_err(dsi->dev, "Packet Tx payload size (%d) too > large", > + (unsigned int)packet.payload_length); > + return -ENOSPC; > + } > + > + /* Copy TX packet payload data to memory space */ > + memcpy(dsi->dcs_buf_virt, packet.payload, > packet.payload_length); > + } else { > + value |= SQCH0DSC0AR_FMT_SHORT; > + } > + > + rzg2l_mipi_dsi_link_write(dsi, SQCH0DSC0AR, value); > + > + /* > + * Write: specify payload data source location, only used for > + * long packet. > + * Read: specify payload data storage location of response > + * packet. Note: a read packet is always a short packet. > + * If the response packet is a short packet or a long packet > + * with WC = 0 (no payload), DTSEL is meaningless. > + */ > + rzg2l_mipi_dsi_link_write(dsi, SQCH0DSC0BR, > +SQCH0DSC0BR_DTSEL_MEM_SPACE); > + > + /* > + * Set SQCHxSR.AACTFIN bit when descriptor actions are finished. > + * Read: set Rx result save slot number to 0 (ACTCODE). > + */ > + rzg2l_mipi_dsi_link_write(dsi, SQCH0DSC0CR, SQCH0DSC0CR_FINACT); > + > + /* Set rx/tx payload data address, only relevant for long packet. */ > + rzg2l_mipi_dsi_link_write(dsi, SQCH0DSC0DR, (u32)dsi->dcs_buf_phys); > + > + /* Start sequence 0 operation */ > + value = rzg2l_mipi_dsi_link_read(dsi, SQCH0SET0R); > + value |= SQCH0SET0R_START; > + rzg2l_mipi_dsi_link_write(dsi, SQCH0SET0R, value); > + > + /* Wait for operation to finish */ > + ret = read_poll_timeout(rzg2l_mipi_dsi_link_read, > + value, value & SQCH0SR_ADESFIN, > + 2000, 20000, false, dsi, SQCH0SR); > + if (ret == 0) { > + /* Success: clear status bit */ > + rzg2l_mipi_dsi_link_write(dsi, SQCH0SCR, SQCH0SCR_ADESFIN); > + > + if (need_bta) > + ret = rzg2l_mipi_dsi_read_response(dsi, msg); > + else > + ret = packet.payload_length; > + } > + > + return ret; > +} > + > static const struct mipi_dsi_host_ops rzg2l_mipi_dsi_host_ops = { > .attach = rzg2l_mipi_dsi_host_attach, > .detach = rzg2l_mipi_dsi_host_detach, > + .transfer = rzg2l_mipi_dsi_host_transfer, > }; > > /* > ----------------------------------------------------------------------------- > @@ -771,6 +938,11 @@ static int rzg2l_mipi_dsi_probe(struct platform_device > *pdev) > if (ret < 0) > goto err_pm_disable; > > + dsi->dcs_buf_virt = dma_alloc_coherent(dsi->host.dev, > RZG2L_DCS_BUF_SIZE, > + &dsi->dcs_buf_phys, GFP_KERNEL); > + if (!dsi->dcs_buf_virt) > + return -ENOMEM; > + > return 0; > > err_phy: > @@ -785,6 +957,8 @@ static void rzg2l_mipi_dsi_remove(struct platform_device > *pdev) { > struct rzg2l_mipi_dsi *dsi = platform_get_drvdata(pdev); > > + dma_free_coherent(dsi->host.dev, RZG2L_DCS_BUF_SIZE, dsi->dcs_buf_virt, > + dsi->dcs_buf_phys); > mipi_dsi_host_unregister(&dsi->host); > pm_runtime_disable(&pdev->dev); > } > diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h > b/drivers/gpu/drm/renesas/rz- > du/rzg2l_mipi_dsi_regs.h > index 1dbc16ec64a4b..33cd669bc74b1 100644 > --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h > +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi_regs.h > @@ -81,6 +81,16 @@ > #define RSTSR_SWRSTLP (1 << 1) > #define RSTSR_SWRSTHS (1 << 0) > > +/* Rx Result Save Slot 0 Register */ > +#define RXRSS0R 0x240 > +#define RXRSS0R_RXPKTDFAIL BIT(28) > +#define RXRSS0R_RXFAIL BIT(27) > +#define RXRSS0R_RXSUC BIT(25) > +#define RXRSS0R_DT GENMASK(21, 16) > +#define RXRSS0R_DATA1 GENMASK(15, 8) > +#define RXRSS0R_DATA0 GENMASK(7, 0) > +#define RXRSS0R_WC GENMASK(15, 0) /* Word count for long > packet. */ > + > /* Clock Lane Stop Time Set Register */ > #define CLSTPTSETR 0x314 > #define CLSTPTSETR_CLKKPT(x) ((x) << 24) > @@ -148,4 +158,50 @@ > #define VICH1HPSETR_HFP(x) (((x) & 0x1fff) << 16) > #define VICH1HPSETR_HBP(x) (((x) & 0x1fff) << 0) > > +/* Sequence Channel 0 Set 0 Register */ > +#define SQCH0SET0R 0x5c0 > +#define SQCH0SET0R_START BIT(0) > + > +/* Sequence Channel 0 Set 1 Register */ > +#define SQCH0SET1R 0x5c4 Unused. Drop it. > + > +/* Sequence Channel 0 Status Register */ > +#define SQCH0SR 0x5d0 > +#define SQCH0SR_RUNNING BIT(2) Unused > +#define SQCH0SR_ADESFIN BIT(8) > + > +/* Sequence Channel 0 Status Clear Register */ > +#define SQCH0SCR 0x5d4 > +#define SQCH0SCR_ADESFIN BIT(8) > + > +/* Sequence Channel 0 Descriptor 0-A Register */ > +#define SQCH0DSC0AR 0x780 > +#define SQCH0DSC0AR_NXACT_TERM 0 > +#define SQCH0DSC0AR_NXACT_OPER BIT(28) Unused > +#define SQCH0DSC0AR_BTA GENMASK(27, 26) > +#define SQCH0DSC0AR_BTA_NONE 0 > +#define SQCH0DSC0AR_BTA_NON_READ 1 > +#define SQCH0DSC0AR_BTA_READ 2 > +#define SQCH0DSC0AR_BTA_ONLY 3 > +#define SQCH0DSC0AR_SPD_HIGH 0 > +#define SQCH0DSC0AR_SPD_LOW BIT(25) > +#define SQCH0DSC0AR_FMT_SHORT 0 > +#define SQCH0DSC0AR_FMT_LONG BIT(24) > +#define SQCH0DSC0AR_DT GENMASK(21, 16) > +#define SQCH0DSC0AR_DATA1 GENMASK(15, 8) > +#define SQCH0DSC0AR_DATA0 GENMASK(7, 0) > + > +/* Sequence Channel 0 Descriptor 0-B Register */ > +#define SQCH0DSC0BR 0x784 > +#define SQCH0DSC0BR_DTSEL_PAYLOAD_DR 0 /* Use packet payload data > register */ Unused > +#define SQCH0DSC0BR_DTSEL_MEM_SPACE BIT(24) /* Use external memory */ > + > +/* Sequence Channel 0 Descriptor 0-C Register */ > +#define SQCH0DSC0CR 0x788 > +#define SQCH0DSC0CR_FINACT BIT(0) > +#define SQCH0DSC0CR_AUXOP BIT(22) Unused > + > +/* Sequence Channel 0 Descriptor 0-D Register */ > +#define SQCH0DSC0DR 0x78c > + Cheers, Biju > #endif /* __RZG2L_MIPI_DSI_REGS_H__ */ > -- > 2.39.5
