12 /* Functions for DMA support */
18 	struct stm32_i2c_dma *dma;  in stm32_i2c_dma_request()  local
22 	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);  in stm32_i2c_dma_request()
23 	if (!dma)  in stm32_i2c_dma_request()
26 	/* Request and configure I2C TX dma channel */  in stm32_i2c_dma_request()
27 	dma->chan_tx = dma_request_chan(dev, "tx");  in stm32_i2c_dma_request()
28 	if (IS_ERR(dma->chan_tx)) {  in stm32_i2c_dma_request()
29 		dev_dbg(dev, "can't request DMA tx channel\n");  in stm32_i2c_dma_request()
30 		ret = PTR_ERR(dma->chan_tx);  in stm32_i2c_dma_request()
39 	ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);  in stm32_i2c_dma_request()
45 	/* Request and configure I2C RX dma channel */  in stm32_i2c_dma_request()
46 	dma->chan_rx = dma_request_chan(dev, "rx");  in stm32_i2c_dma_request()
47 	if (IS_ERR(dma->chan_rx)) {  in stm32_i2c_dma_request()
48 		dev_err(dev, "can't request DMA rx channel\n");  in stm32_i2c_dma_request()
49 		ret = PTR_ERR(dma->chan_rx);  in stm32_i2c_dma_request()
58 	ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);  in stm32_i2c_dma_request()
64 	init_completion(&dma->dma_complete);  in stm32_i2c_dma_request()
66 	dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",  in stm32_i2c_dma_request()
67 		 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));  in stm32_i2c_dma_request()
69 	return dma;  in stm32_i2c_dma_request()
72 	dma_release_channel(dma->chan_rx);  in stm32_i2c_dma_request()
74 	dma_release_channel(dma->chan_tx);  in stm32_i2c_dma_request()
76 	devm_kfree(dev, dma);  in stm32_i2c_dma_request()
77 	dev_info(dev, "can't use DMA\n");  in stm32_i2c_dma_request()
82 void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)  in stm32_i2c_dma_free()  argument
84 	dma->dma_buf = 0;  in stm32_i2c_dma_free()
85 	dma->dma_len = 0;  in stm32_i2c_dma_free()
87 	dma_release_channel(dma->chan_tx);  in stm32_i2c_dma_free()
88 	dma->chan_tx = NULL;  in stm32_i2c_dma_free()
90 	dma_release_channel(dma->chan_rx);  in stm32_i2c_dma_free()
91 	dma->chan_rx = NULL;  in stm32_i2c_dma_free()
93 	dma->chan_using = NULL;  in stm32_i2c_dma_free()
96 int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,  in stm32_i2c_prep_dma_xfer()  argument
106 		dma->chan_using = dma->chan_rx;  in stm32_i2c_prep_dma_xfer()
107 		dma->dma_transfer_dir = DMA_DEV_TO_MEM;  in stm32_i2c_prep_dma_xfer()
108 		dma->dma_data_dir = DMA_FROM_DEVICE;  in stm32_i2c_prep_dma_xfer()
110 		dma->chan_using = dma->chan_tx;  in stm32_i2c_prep_dma_xfer()
111 		dma->dma_transfer_dir = DMA_MEM_TO_DEV;  in stm32_i2c_prep_dma_xfer()
112 		dma->dma_data_dir = DMA_TO_DEVICE;  in stm32_i2c_prep_dma_xfer()
115 	dma->dma_len = len;  in stm32_i2c_prep_dma_xfer()
116 	chan_dev = dma->chan_using->device->dev;  in stm32_i2c_prep_dma_xfer()
118 	dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,  in stm32_i2c_prep_dma_xfer()
119 				      dma->dma_data_dir);  in stm32_i2c_prep_dma_xfer()
120 	if (dma_mapping_error(chan_dev, dma->dma_buf)) {  in stm32_i2c_prep_dma_xfer()
121 		dev_err(dev, "DMA mapping failed\n");  in stm32_i2c_prep_dma_xfer()
125 	txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,  in stm32_i2c_prep_dma_xfer()
126 					     dma->dma_len,  in stm32_i2c_prep_dma_xfer()
127 					     dma->dma_transfer_dir,  in stm32_i2c_prep_dma_xfer()
130 		dev_err(dev, "Not able to get desc for DMA xfer\n");  in stm32_i2c_prep_dma_xfer()
135 	reinit_completion(&dma->dma_complete);  in stm32_i2c_prep_dma_xfer()
141 		dev_err(dev, "DMA submit failed\n");  in stm32_i2c_prep_dma_xfer()
145 	dma_async_issue_pending(dma->chan_using);  in stm32_i2c_prep_dma_xfer()
150 	dma_unmap_single(chan_dev, dma->dma_buf, dma->dma_len,  in stm32_i2c_prep_dma_xfer()
151 			 dma->dma_data_dir);  in stm32_i2c_prep_dma_xfer()