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path: root/drivers/i2c/busses/i2c-sh_mobile.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-sh_mobile.c')
-rw-r--r--drivers/i2c/busses/i2c-sh_mobile.c112
1 files changed, 54 insertions, 58 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index d7efaf44868b..440d5dbc8b5f 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -140,6 +140,7 @@ struct sh_mobile_i2c_data {
int sr;
bool send_stop;
+ struct resource *res;
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
struct scatterlist sg;
@@ -539,6 +540,42 @@ static void sh_mobile_i2c_dma_callback(void *data)
iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE);
}
+static struct dma_chan *sh_mobile_i2c_request_dma_chan(struct device *dev,
+ enum dma_transfer_direction dir, dma_addr_t port_addr)
+{
+ struct dma_chan *chan;
+ struct dma_slave_config cfg;
+ char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
+ int ret;
+
+ chan = dma_request_slave_channel_reason(dev, chan_name);
+ if (IS_ERR(chan)) {
+ ret = PTR_ERR(chan);
+ dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret);
+ return chan;
+ }
+
+ memset(&cfg, 0, sizeof(cfg));
+ cfg.direction = dir;
+ if (dir == DMA_MEM_TO_DEV) {
+ cfg.dst_addr = port_addr;
+ cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ } else {
+ cfg.src_addr = port_addr;
+ cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ }
+
+ ret = dmaengine_slave_config(chan, &cfg);
+ if (ret) {
+ dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
+ dma_release_channel(chan);
+ return ERR_PTR(ret);
+ }
+
+ dev_dbg(dev, "got DMA channel for %s\n", chan_name);
+ return chan;
+}
+
static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
{
bool read = pd->msg->flags & I2C_M_RD;
@@ -548,7 +585,16 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
dma_addr_t dma_addr;
dma_cookie_t cookie;
- if (!chan)
+ if (PTR_ERR(chan) == -EPROBE_DEFER) {
+ if (read)
+ chan = pd->dma_rx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
+ pd->res->start + ICDR);
+ else
+ chan = pd->dma_tx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
+ pd->res->start + ICDR);
+ }
+
+ if (IS_ERR(chan))
return;
dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
@@ -747,56 +793,16 @@ static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
-static int sh_mobile_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir,
- dma_addr_t port_addr, struct dma_chan **chan_ptr)
-{
- struct dma_chan *chan;
- struct dma_slave_config cfg;
- char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
- int ret;
-
- *chan_ptr = NULL;
-
- chan = dma_request_slave_channel_reason(dev, chan_name);
- if (IS_ERR(chan)) {
- ret = PTR_ERR(chan);
- dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret);
- return ret;
- }
-
- memset(&cfg, 0, sizeof(cfg));
- cfg.direction = dir;
- if (dir == DMA_MEM_TO_DEV) {
- cfg.dst_addr = port_addr;
- cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
- } else {
- cfg.src_addr = port_addr;
- cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
- }
-
- ret = dmaengine_slave_config(chan, &cfg);
- if (ret) {
- dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret);
- dma_release_channel(chan);
- return ret;
- }
-
- *chan_ptr = chan;
-
- dev_dbg(dev, "got DMA channel for %s\n", chan_name);
- return 0;
-}
-
static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd)
{
- if (pd->dma_tx) {
+ if (!IS_ERR(pd->dma_tx)) {
dma_release_channel(pd->dma_tx);
- pd->dma_tx = NULL;
+ pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
}
- if (pd->dma_rx) {
+ if (!IS_ERR(pd->dma_rx)) {
dma_release_channel(pd->dma_rx);
- pd->dma_rx = NULL;
+ pd->dma_rx = ERR_PTR(-EPROBE_DEFER);
}
}
@@ -849,6 +855,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ pd->res = res;
pd->reg = devm_ioremap_resource(&dev->dev, res);
if (IS_ERR(pd->reg))
return PTR_ERR(pd->reg);
@@ -889,17 +896,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
/* Init DMA */
sg_init_table(&pd->sg, 1);
pd->dma_direction = DMA_NONE;
- ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM,
- res->start + ICDR, &pd->dma_rx);
- if (ret == -EPROBE_DEFER)
- return ret;
-
- ret = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV,
- res->start + ICDR, &pd->dma_tx);
- if (ret == -EPROBE_DEFER) {
- sh_mobile_i2c_release_dma(pd);
- return ret;
- }
+ pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
/* Enable Runtime PM for this device.
*
@@ -937,8 +934,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
return ret;
}
- dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz, DMA=%c\n",
- adap->nr, pd->bus_speed, (pd->dma_rx || pd->dma_tx) ? 'y' : 'n');
+ dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz\n", adap->nr, pd->bus_speed);
return 0;
}