From dfebb055f73a24e2c8756b837d9ce1a06457f5d7 Mon Sep 17 00:00:00 2001 From: Abhishek Sahu Date: Tue, 1 Aug 2017 19:41:43 +0530 Subject: [PATCH] dmaengine: qcom: bam_dma: wrapper functions for command descriptor QCOM BAM also supports command descriptor which allows the SW to create descriptors of type command which does not generate any data transmissions but configures registers in the peripheral. In command descriptor the 32bit address point to the start of the command block which holds the command elements and the 16bit size define the size of the command block. Each Command Element is structured by 4 words: Write command: address + cmd register data register mask reserved Read command: address + cmd read data result address, reserved reserved This patch creates a new header file for BAM driver which contains the structures and wrapper functions for command descriptor. This file will be used by different QCOM peripheral drivers for forming the command descriptor Signed-off-by: Abhishek Sahu Signed-off-by: Vinod Koul --- include/linux/dma/qcom_bam_dma.h | 79 ++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 include/linux/dma/qcom_bam_dma.h diff --git a/include/linux/dma/qcom_bam_dma.h b/include/linux/dma/qcom_bam_dma.h new file mode 100644 index 000000000000..077d43a358e5 --- /dev/null +++ b/include/linux/dma/qcom_bam_dma.h @@ -0,0 +1,79 @@ +/* + * Copyright (c) 2016-2017, The Linux Foundation. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _QCOM_BAM_DMA_H +#define _QCOM_BAM_DMA_H + +#include + +/* + * This data type corresponds to the native Command Element + * supported by BAM DMA Engine. + * + * @cmd_and_addr - upper 8 bits command and lower 24 bits register address. + * @data - for write command: content to be written into peripheral register. + * for read command: dest addr to write peripheral register value. + * @mask - register mask. + * @reserved - for future usage. + * + */ +struct bam_cmd_element { + __le32 cmd_and_addr; + __le32 data; + __le32 mask; + __le32 reserved; +}; + +/* + * This enum indicates the command type in a command element + */ +enum bam_command_type { + BAM_WRITE_COMMAND = 0, + BAM_READ_COMMAND, +}; + +/* + * prep_bam_ce_le32 - Wrapper function to prepare a single BAM command + * element with the data already in le32 format. + * + * @bam_ce: bam command element + * @addr: target address + * @cmd: BAM command + * @data: actual data for write and dest addr for read in le32 + */ +static inline void +bam_prep_ce_le32(struct bam_cmd_element *bam_ce, u32 addr, + enum bam_command_type cmd, __le32 data) +{ + bam_ce->cmd_and_addr = + cpu_to_le32((addr & 0xffffff) | ((cmd & 0xff) << 24)); + bam_ce->data = data; + bam_ce->mask = cpu_to_le32(0xffffffff); +} + +/* + * bam_prep_ce - Wrapper function to prepare a single BAM command element + * with the data. + * + * @bam_ce: BAM command element + * @addr: target address + * @cmd: BAM command + * @data: actual data for write and dest addr for read + */ +static inline void +bam_prep_ce(struct bam_cmd_element *bam_ce, u32 addr, + enum bam_command_type cmd, u32 data) +{ + bam_prep_ce_le32(bam_ce, addr, cmd, cpu_to_le32(data)); +} +#endif