tn3399_openwrt/target/linux/ipq40xx/patches-4.14/088-0003-i2c-qup-minor-code-reorganization-for-use_dma.patch
Piotr Dymacz 24de7c29e5 ipq40xx: backport I2C QUP driver changes from 4.17
Backport below changes for I2C QUP driver from v4.17:

  0668bc44a426 i2c: qup: fix copyrights and update to SPDX identifier
  7239872fb340 i2c: qup: fixed releasing dma without flush operation completion
  eb422b539c1f i2c: qup: minor code reorganization for use_dma
  6d5f37f166bb i2c: qup: remove redundant variables for BAM SG count
  c5adc0fa63a9 i2c: qup: schedule EOT and FLUSH tags at the end of transfer
  7e6c35fe602d i2c: qup: fix the transfer length for BAM RX EOT FLUSH tags
  3f450d3eea14 i2c: qup: proper error handling for i2c error in BAM mode
  08f15963bc75 i2c: qup: use the complete transfer length to choose DMA mode
  ecb6e1e5f435 i2c: qup: change completion timeout according to transfer length
  6f2f0f6465ac i2c: qup: fix buffer overflow for multiple msg of maximum xfer len
  f7714b4e451b i2c: qup: send NACK for last read sub transfers
  fbfab1ab0658 i2c: qup: reorganization of driver code to remove polling for qup v1
  7545c7dba169 i2c: qup: reorganization of driver code to remove polling for qup v2

This fixes various I2C issues observed on AP120C-AC board equipped with
Atmel/Microchip AT97SC3205T TPM module.

Tested-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>
2019-03-08 19:28:31 +01:00

77 lines
2.2 KiB
Diff

From eb422b539c1f39faf576826b54be93e84d9cb32a Mon Sep 17 00:00:00 2001
From: Abhishek Sahu <absahu@codeaurora.org>
Date: Mon, 12 Mar 2018 18:44:52 +0530
Subject: [PATCH 03/13] i2c: qup: minor code reorganization for use_dma
1. Assigns use_dma in qup_dev structure itself which will
help in subsequent patches to determine the mode in IRQ handler.
2. Does minor code reorganization for loops to reduce the
unnecessary comparison and assignment.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
drivers/i2c/busses/i2c-qup.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -181,6 +181,8 @@ struct qup_i2c_dev {
/* dma parameters */
bool is_dma;
+ /* To check if the current transfer is using DMA */
+ bool use_dma;
struct dma_pool *dpool;
struct qup_i2c_tag start_tag;
struct qup_i2c_bam brx;
@@ -1288,7 +1290,7 @@ static int qup_i2c_xfer_v2(struct i2c_ad
int num)
{
struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
- int ret, len, idx = 0, use_dma = 0;
+ int ret, len, idx = 0;
qup->bus_err = 0;
qup->qup_err = 0;
@@ -1317,13 +1319,12 @@ static int qup_i2c_xfer_v2(struct i2c_ad
len = (msgs[idx].len > qup->out_fifo_sz) ||
(msgs[idx].len > qup->in_fifo_sz);
- if ((!is_vmalloc_addr(msgs[idx].buf)) && len) {
- use_dma = 1;
- } else {
- use_dma = 0;
+ if (is_vmalloc_addr(msgs[idx].buf) || !len)
break;
- }
}
+
+ if (idx == num)
+ qup->use_dma = true;
}
idx = 0;
@@ -1347,15 +1348,17 @@ static int qup_i2c_xfer_v2(struct i2c_ad
reinit_completion(&qup->xfer);
- if (use_dma) {
+ if (qup->use_dma) {
ret = qup_i2c_bam_xfer(adap, &msgs[idx], num);
+ qup->use_dma = false;
+ break;
} else {
if (msgs[idx].flags & I2C_M_RD)
ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
else
ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
}
- } while ((idx++ < (num - 1)) && !use_dma && !ret);
+ } while ((idx++ < (num - 1)) && !ret);
if (!ret)
ret = qup_i2c_change_state(qup, QUP_RESET_STATE);