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Subject[PATCH] mmc: sh_mmcif: rework dma channel handling
Date
When compiling the sh_mmcif driver for ARM64, we currently
get a harmless build warning:

../drivers/mmc/host/sh_mmcif.c: In function 'sh_mmcif_request_dma_one':
../drivers/mmc/host/sh_mmcif.c:417:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
(void *)pdata->slave_id_tx :
^
../drivers/mmc/host/sh_mmcif.c:418:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
(void *)pdata->slave_id_rx;

This could be worked around by adding another cast to uintptr_t, but
I decided to simplify the code a little more to avoid that. This
splits out the platform data using code into a separate function
and builds that only for CONFIG_SUPERH. This part still has a typecast
but does not need a second one. The SH platform code could be further
modified to pass a pointer directly as we do on other architectures
when we have a filter function.

The normal case is simplified further and now just calls
dma_request_slave_channel() directly without going through the
compat handling.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/mmc/host/sh_mmcif.c | 80 +++++++++++++++++---------------------------------
1 file changed, 34 insertions(+), 46 deletions(-)


diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index ad9ffea7d659..d964c99f3a30 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -397,38 +397,26 @@ static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host)
}

static struct dma_chan *
-sh_mmcif_request_dma_one(struct sh_mmcif_host *host,
- struct sh_mmcif_plat_data *pdata,
- enum dma_transfer_direction direction)
+sh_mmcif_request_dma_pdata(struct sh_mmcif_host *host, uintptr_t slave_id)
{
- struct dma_slave_config cfg = { 0, };
- struct dma_chan *chan;
- void *slave_data = NULL;
- struct resource *res;
- struct device *dev = sh_mmcif_host_to_dev(host);
dma_cap_mask_t mask;
- int ret;

dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
+ if (slave_id <= 0)
+ return NULL;

- if (pdata)
- slave_data = direction == DMA_MEM_TO_DEV ?
- (void *)pdata->slave_id_tx :
- (void *)pdata->slave_id_rx;
-
- chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
- slave_data, dev,
- direction == DMA_MEM_TO_DEV ? "tx" : "rx");
-
- dev_dbg(dev, "%s: %s: got channel %p\n", __func__,
- direction == DMA_MEM_TO_DEV ? "TX" : "RX", chan);
+ return dma_request_channel(mask, shdma_chan_filter, (void *)slave_id);
+}

- if (!chan)
- return NULL;
+static int sh_mmcif_dma_slave_config(struct sh_mmcif_host *host,
+ struct dma_chan *chan,
+ enum dma_transfer_direction direction)
+{
+ struct resource *res;
+ struct dma_slave_config cfg = { 0, };

res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
-
cfg.direction = direction;

if (direction == DMA_DEV_TO_MEM) {
@@ -439,38 +427,38 @@ sh_mmcif_request_dma_one(struct sh_mmcif_host *host,
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
}

- ret = dmaengine_slave_config(chan, &cfg);
- if (ret < 0) {
- dma_release_channel(chan);
- return NULL;
- }
-
- return chan;
+ return dmaengine_slave_config(chan, &cfg);
}

-static void sh_mmcif_request_dma(struct sh_mmcif_host *host,
- struct sh_mmcif_plat_data *pdata)
+static void sh_mmcif_request_dma(struct sh_mmcif_host *host)
{
struct device *dev = sh_mmcif_host_to_dev(host);
host->dma_active = false;

- if (pdata) {
- if (pdata->slave_id_tx <= 0 || pdata->slave_id_rx <= 0)
- return;
- } else if (!dev->of_node) {
- return;
+ /* We can only either use DMA for both Tx and Rx or not use it at all */
+ if (IS_ENABLED(CONFIG_SUPERH) && dev->platform_data) {
+ struct sh_mmcif_plat_data *pdata = dev->platform_data;
+ host->chan_tx = sh_mmcif_request_dma_pdata(host, pdata->slave_id_tx);
+ host->chan_rx = sh_mmcif_request_dma_pdata(host, pdata->slave_id_rx);
+ } else {
+ host->chan_tx = dma_request_slave_channel(dev, "tx");
+ host->chan_tx = dma_request_slave_channel(dev, "rx");
}
+ dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx, host->chan_rx);

- /* We can only either use DMA for both Tx and Rx or not use it at all */
- host->chan_tx = sh_mmcif_request_dma_one(host, pdata, DMA_MEM_TO_DEV);
- if (!host->chan_tx)
- return;
+ if (!host->chan_tx || !host->chan_rx ||
+ sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) ||
+ sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM))
+ goto error;

- host->chan_rx = sh_mmcif_request_dma_one(host, pdata, DMA_DEV_TO_MEM);
- if (!host->chan_rx) {
+ return;
+
+error:
+ if (host->chan_tx)
dma_release_channel(host->chan_tx);
- host->chan_tx = NULL;
- }
+ if (host->chan_rx)
+ dma_release_channel(host->chan_rx);
+ host->chan_tx = host->chan_rx = NULL;
}

static void sh_mmcif_release_dma(struct sh_mmcif_host *host)
@@ -1102,7 +1090,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (ios->power_mode == MMC_POWER_UP) {
if (!host->card_present) {
/* See if we also get DMA */
- sh_mmcif_request_dma(host, dev->platform_data);
+ sh_mmcif_request_dma(host);
host->card_present = true;
}
sh_mmcif_set_power(host, ios);


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