mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 18:09:57 +00:00
![Krzysztof Kozlowski](/assets/img/avatar_default.png)
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and the error value gets printed. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Alain Volmat <alain.volmat@st.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
156 lines
3.7 KiB
C
156 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* i2c-stm32.c
|
|
*
|
|
* Copyright (C) M'boumba Cedric Madianga 2017
|
|
* Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
|
|
*/
|
|
|
|
#include "i2c-stm32.h"
|
|
|
|
/* Functions for DMA support */
|
|
struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
|
|
dma_addr_t phy_addr,
|
|
u32 txdr_offset,
|
|
u32 rxdr_offset)
|
|
{
|
|
struct stm32_i2c_dma *dma;
|
|
struct dma_slave_config dma_sconfig;
|
|
int ret;
|
|
|
|
dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
|
|
if (!dma)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/* Request and configure I2C TX dma channel */
|
|
dma->chan_tx = dma_request_chan(dev, "tx");
|
|
if (IS_ERR(dma->chan_tx)) {
|
|
ret = PTR_ERR(dma->chan_tx);
|
|
if (ret != -ENODEV)
|
|
ret = dev_err_probe(dev, ret,
|
|
"can't request DMA tx channel\n");
|
|
goto fail_al;
|
|
}
|
|
|
|
memset(&dma_sconfig, 0, sizeof(dma_sconfig));
|
|
dma_sconfig.dst_addr = phy_addr + txdr_offset;
|
|
dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
|
|
dma_sconfig.dst_maxburst = 1;
|
|
dma_sconfig.direction = DMA_MEM_TO_DEV;
|
|
ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
|
|
if (ret < 0) {
|
|
dev_err(dev, "can't configure tx channel\n");
|
|
goto fail_tx;
|
|
}
|
|
|
|
/* Request and configure I2C RX dma channel */
|
|
dma->chan_rx = dma_request_chan(dev, "rx");
|
|
if (IS_ERR(dma->chan_rx)) {
|
|
ret = PTR_ERR(dma->chan_rx);
|
|
if (ret != -ENODEV)
|
|
ret = dev_err_probe(dev, ret,
|
|
"can't request DMA rx channel\n");
|
|
|
|
goto fail_tx;
|
|
}
|
|
|
|
memset(&dma_sconfig, 0, sizeof(dma_sconfig));
|
|
dma_sconfig.src_addr = phy_addr + rxdr_offset;
|
|
dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
|
|
dma_sconfig.src_maxburst = 1;
|
|
dma_sconfig.direction = DMA_DEV_TO_MEM;
|
|
ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
|
|
if (ret < 0) {
|
|
dev_err(dev, "can't configure rx channel\n");
|
|
goto fail_rx;
|
|
}
|
|
|
|
init_completion(&dma->dma_complete);
|
|
|
|
dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
|
|
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
|
|
|
|
return dma;
|
|
|
|
fail_rx:
|
|
dma_release_channel(dma->chan_rx);
|
|
fail_tx:
|
|
dma_release_channel(dma->chan_tx);
|
|
fail_al:
|
|
devm_kfree(dev, dma);
|
|
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
|
|
{
|
|
dma->dma_buf = 0;
|
|
dma->dma_len = 0;
|
|
|
|
dma_release_channel(dma->chan_tx);
|
|
dma->chan_tx = NULL;
|
|
|
|
dma_release_channel(dma->chan_rx);
|
|
dma->chan_rx = NULL;
|
|
|
|
dma->chan_using = NULL;
|
|
}
|
|
|
|
int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
|
|
bool rd_wr, u32 len, u8 *buf,
|
|
dma_async_tx_callback callback,
|
|
void *dma_async_param)
|
|
{
|
|
struct dma_async_tx_descriptor *txdesc;
|
|
struct device *chan_dev;
|
|
int ret;
|
|
|
|
if (rd_wr) {
|
|
dma->chan_using = dma->chan_rx;
|
|
dma->dma_transfer_dir = DMA_DEV_TO_MEM;
|
|
dma->dma_data_dir = DMA_FROM_DEVICE;
|
|
} else {
|
|
dma->chan_using = dma->chan_tx;
|
|
dma->dma_transfer_dir = DMA_MEM_TO_DEV;
|
|
dma->dma_data_dir = DMA_TO_DEVICE;
|
|
}
|
|
|
|
dma->dma_len = len;
|
|
chan_dev = dma->chan_using->device->dev;
|
|
|
|
dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
|
|
dma->dma_data_dir);
|
|
if (dma_mapping_error(chan_dev, dma->dma_buf)) {
|
|
dev_err(dev, "DMA mapping failed\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
|
|
dma->dma_len,
|
|
dma->dma_transfer_dir,
|
|
DMA_PREP_INTERRUPT);
|
|
if (!txdesc) {
|
|
dev_err(dev, "Not able to get desc for DMA xfer\n");
|
|
ret = -EINVAL;
|
|
goto err;
|
|
}
|
|
|
|
reinit_completion(&dma->dma_complete);
|
|
|
|
txdesc->callback = callback;
|
|
txdesc->callback_param = dma_async_param;
|
|
ret = dma_submit_error(dmaengine_submit(txdesc));
|
|
if (ret < 0) {
|
|
dev_err(dev, "DMA submit failed\n");
|
|
goto err;
|
|
}
|
|
|
|
dma_async_issue_pending(dma->chan_using);
|
|
|
|
return 0;
|
|
|
|
err:
|
|
dma_unmap_single(chan_dev, dma->dma_buf, dma->dma_len,
|
|
dma->dma_data_dir);
|
|
return ret;
|
|
}
|