From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751210AbdAVDJ5 (ORCPT ); Sat, 21 Jan 2017 22:09:57 -0500 Received: from regular1.263xmail.com ([211.150.99.134]:43482 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741AbdAVDJk (ORCPT ); Sat, 21 Jan 2017 22:09:40 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: zyw@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: zyw@rock-chips.com X-UNIQUE-TAG: <0369acd0922eb99fc8695dbac283cc61> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH v2 26/26] drm/rockchip: dw-mipi-dsi: support read commands To: John Keeping , Mark Yao References: <20170121163128.22240-1-john@metanate.com> <20170121163128.22240-27-john@metanate.com> Cc: dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org From: Chris Zhong Message-ID: <58842245.6000103@rock-chips.com> Date: Sun, 22 Jan 2017 11:08:53 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20170121163128.22240-27-john@metanate.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi John On 01/22/2017 12:31 AM, John Keeping wrote: > I haven't found any method for getting the length of a response, so this > just uses the requested rx_len > > Signed-off-by: John Keeping > --- > Unchanged in v2 > --- > drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 54 ++++++++++++++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > index f780401e8b5e..f0cb005c6d76 100644 > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c > @@ -675,6 +675,54 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, > return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val); > } > > +static int dw_mipi_dsi_dcs_read(struct dw_mipi_dsi *dsi, > + const struct mipi_dsi_msg *msg) > +{ > + const u8 *tx_buf = msg->tx_buf; > + u8 *rx_buf = msg->rx_buf; > + size_t i; > + int ret, val; > + > + dsi_write(dsi, DSI_PCKHDL_CFG, EN_CRC_RX | EN_ECC_RX | EN_BTA); > + dsi_write(dsi, DSI_GEN_HDR, GEN_HDATA(tx_buf[0]) | GEN_HTYPE(msg->type)); WARNING: line over 80 characters > + > + ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, > + val, !(val & GEN_RD_CMD_BUSY), 1000, > + CMD_PKT_STATUS_TIMEOUT_US); > + if (ret < 0) { > + dev_err(dsi->dev, "failed to read command response\n"); > + return ret; > + } > + > + for (i = 0; i < msg->rx_len;) { > + u32 pld = dsi_read(dsi, DSI_GEN_PLD_DATA); > + while (i < msg->rx_len) { > + rx_buf[i] = pld & 0xff; > + pld >>= 8; > + i++; > + } > + } > + > + return msg->rx_len; > +} > + > +static int dw_mipi_dsi_set_max_return_packet_size(struct dw_mipi_dsi *dsi, > + size_t len) > +{ > + u8 val[] = { len & 0xff, (len >> 8) & 0xff }; > + struct mipi_dsi_msg msg = { > + .channel = dsi->channel, > + .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE, > + .tx_buf = val, > + .tx_len = 2, > + }; > + > + if (len > 0xffff) > + return -EINVAL; > + > + return dw_mipi_dsi_dcs_short_write(dsi, &msg); > +} > + > static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > const struct mipi_dsi_msg *msg) > { > @@ -692,6 +740,12 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > case MIPI_DSI_DCS_LONG_WRITE: > ret = dw_mipi_dsi_dcs_long_write(dsi, msg); > break; > + case MIPI_DSI_DCS_READ: > + ret = dw_mipi_dsi_set_max_return_packet_size(dsi, msg->rx_len); > + if (ret < 0) > + return ret; > + ret = dw_mipi_dsi_dcs_read(dsi, msg); > + break; > default: > dev_err(dsi->dev, "unsupported message type 0x%02x\n", > msg->type);