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[24.22.235.96]) by smtp.gmail.com with ESMTPSA id d132sm6527348pfd.61.2019.06.05.00.05.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 05 Jun 2019 00:05:32 -0700 (PDT) From: Andrey Smirnov To: dri-devel@lists.freedesktop.org Subject: [PATCH v3 07/15] drm/bridge: tc358767: Simplify AUX data write Date: Wed, 5 Jun 2019 00:04:59 -0700 Message-Id: <20190605070507.11417-8-andrew.smirnov@gmail.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190605070507.11417-1-andrew.smirnov@gmail.com> References: <20190605070507.11417-1-andrew.smirnov@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Wed, 05 Jun 2019 07:33:23 +0000 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/TiqV4mMjweNF+QK2RThSopUBwGbQaMYJC9n9xdVUsw=; b=FMqlvux0IyVO4Q2gN5is5VAXLp56S9MMHjROii34P7CJIrq248pneh1idjkzxPzSdO y4Eqy/wzHbvhzs8GDgsr4kdWcHYK9YM0/ZO1hUta8o4v4zbl2VGJZvTeVBSmA9ByXw3R gZJZLBz4kejggi8nxi5tqJ8Er+wa83oE7/B/VhGvwhNlqf8VQs1iqO2Z/a286RU19H5n rbfSJYsT4h8qnQQipR0Y6aL2fgQqMAOZA6HhJ1bXSnxrEYRyzxxe4kwkfqgDCW+aEUlJ bCZu+2euB9BrbXow+VX3KQ7WfKVOfcd4t29n98BXEoy3Mw7QKKIpv5qw8M7gdhyBl8AH NSkQ== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cory Tusar , Archit Taneja , Andrey Smirnov , Andrey Gusakov , linux-kernel@vger.kernel.org, Tomi Valkeinen , Laurent Pinchart , Chris Healy Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Simplify AUX data write by dropping index arithmetic and shifting and replacing it with a call to a helper function that does three things: 1. Copies user-provided data into a write buffer 2. Optionally fixes the endianness of the write buffer (not needed on LE hosts) 3. Transfers contenst of the write buffer to up to 4 32-bit registers on the chip Note that separate data endianness fix: tmp = (tmp << 8) | buf[i]; that was reserved for DP_AUX_I2C_WRITE looks really strange, since it will place data differently depending on the passed user-data size. E.g. for a write of 1 byte, data transferred to the chip would look like: [byte0] [dummy1] [dummy2] [dummy3] whereas for a write of 4 bytes we'd get: [byte3] [byte2] [byte1] [byte0] Since there's no indication in the datasheet that I2C write buffer should be treated differently than AUX write buffer and no comment in the original code explaining why it was done this way, that special I2C write buffer transformation was dropped in this patch. Signed-off-by: Andrey Smirnov Cc: Archit Taneja Cc: Andrzej Hajda Cc: Laurent Pinchart Cc: Tomi Valkeinen Cc: Andrey Gusakov Cc: Philipp Zabel Cc: Cory Tusar Cc: Chris Healy Cc: Lucas Stach Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Andrzej Hajda --- drivers/gpu/drm/bridge/tc358767.c | 59 +++++++++++++++++++------------ 1 file changed, 37 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index da47d81e7109..260fbcd0271e 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -321,6 +321,32 @@ static int tc_aux_get_status(struct tc_data *tc, u8 *reply) return 0; } +static int tc_aux_write_data(struct tc_data *tc, const void *data, + size_t size) +{ + u32 auxwdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)] = { 0 }; + int ret, i, count = DIV_ROUND_UP(size, sizeof(u32)); + + memcpy(auxwdata, data, size); + + for (i = 0; i < count; i++) { + /* + * Our regmap is configured as LE + * for register data, so we need + * undo any byte swapping that will + * happened to preserve original + * byte order. + */ + cpu_to_le32s(&auxwdata[i]); + } + + ret = regmap_bulk_write(tc->regmap, DP0_AUXWDATA(0), auxwdata, count); + if (ret) + return ret; + + return size; +} + static int tc_aux_read_data(struct tc_data *tc, void *data, size_t size) { u32 auxrdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)]; @@ -350,9 +376,6 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux, struct tc_data *tc = aux_to_tc(aux); size_t size = min_t(size_t, 8, msg->size); u8 request = msg->request & ~DP_AUX_I2C_MOT; - u8 *buf = msg->buffer; - u32 tmp = 0; - int i = 0; int ret; if (size == 0) @@ -362,25 +385,17 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux, if (ret) return ret; - if (request == DP_AUX_I2C_WRITE || request == DP_AUX_NATIVE_WRITE) { - /* Store data */ - while (i < size) { - if (request == DP_AUX_NATIVE_WRITE) - tmp = tmp | (buf[i] << (8 * (i & 0x3))); - else - tmp = (tmp << 8) | buf[i]; - i++; - if (((i % 4) == 0) || (i == size)) { - ret = regmap_write(tc->regmap, - DP0_AUXWDATA((i - 1) >> 2), - tmp); - if (ret) - return ret; - tmp = 0; - } - } - } else if (request != DP_AUX_I2C_READ && - request != DP_AUX_NATIVE_READ) { + switch (request) { + case DP_AUX_NATIVE_READ: + case DP_AUX_I2C_READ: + break; + case DP_AUX_NATIVE_WRITE: + case DP_AUX_I2C_WRITE: + ret = tc_aux_write_data(tc, msg->buffer, size); + if (ret < 0) + return ret; + break; + default: return -EINVAL; }