i2c/busses/i2c-stm32.c

17 	struct stm32_i2c_dma *dma;
21 	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
22 	if (!dma)
25 	/* Request and configure I2C TX dma channel */
26 	dma->chan_tx = dma_request_chan(dev, "tx");
27 	if (IS_ERR(dma->chan_tx)) {
28 		ret = PTR_ERR(dma->chan_tx);
40 	ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
46 	/* Request and configure I2C RX dma channel */
47 	dma->chan_rx = dma_request_chan(dev, "rx");
48 	if (IS_ERR(dma->chan_rx)) {
49 		ret = PTR_ERR(dma->chan_rx);
62 	ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
68 	init_completion(&dma->dma_complete);
71 		 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
73 	return dma;
76 	dma_release_channel(dma->chan_rx);
78 	dma_release_channel(dma->chan_tx);
80 	devm_kfree(dev, dma);
85 void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
87 	dma->dma_buf = 0;
88 	dma->dma_len = 0;
90 	dma_release_channel(dma->chan_tx);
91 	dma->chan_tx = NULL;
93 	dma_release_channel(dma->chan_rx);
94 	dma->chan_rx = NULL;
96 	dma->chan_using = NULL;
99 int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
109 		dma->chan_using = dma->chan_rx;
110 		dma->dma_transfer_dir = DMA_DEV_TO_MEM;
111 		dma->dma_data_dir = DMA_FROM_DEVICE;
113 		dma->chan_using = dma->chan_tx;
114 		dma->dma_transfer_dir = DMA_MEM_TO_DEV;
115 		dma->dma_data_dir = DMA_TO_DEVICE;
118 	dma->dma_len = len;
119 	chan_dev = dma->chan_using->device->dev;
121 	dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
122 				      dma->dma_data_dir);
123 	if (dma_mapping_error(chan_dev, dma->dma_buf)) {
128 	txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
129 					     dma->dma_len,
130 					     dma->dma_transfer_dir,
138 	reinit_completion(&dma->dma_complete);
148 	dma_async_issue_pending(dma->chan_using);
153 	dma_unmap_single(chan_dev, dma->dma_buf, dma->dma_len,
154 			 dma->dma_data_dir);