[PATCH 09/13] atmel-mci: convert to dma_request_channel anddown-level dma_slave

From: Dan Williams
Date: Fri Nov 14 2008 - 16:39:08 EST

dma_request_channel provides an exclusive channel, so we no longer need to
pass slave data through dmaengine.

Cc: Haavard Skinnemoen <haavard.skinnemoen@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---

arch/avr32/include/asm/atmel-mci.h | 6 +-
arch/avr32/mach-at32ap/at32ap700x.c | 15 +----
drivers/dma/dmaengine.c | 8 ---
drivers/dma/dw_dmac.c | 25 ++-------
drivers/mmc/host/atmel-mci.c | 98 ++++++++++-------------------------
include/linux/dmaengine.h | 38 --------------
include/linux/dw_dmac.h | 31 ++++++++---
7 files changed, 62 insertions(+), 159 deletions(-)

diff --git a/arch/avr32/include/asm/atmel-mci.h b/arch/avr32/include/asm/atmel-mci.h
index 59f3fad..e5e54c6 100644
--- a/arch/avr32/include/asm/atmel-mci.h
+++ b/arch/avr32/include/asm/atmel-mci.h
@@ -3,7 +3,7 @@

#define ATMEL_MCI_MAX_NR_SLOTS 2

-struct dma_slave;
+#include <linux/dw_dmac.h>

/**
* struct mci_slot_pdata - board-specific per-slot configuration
@@ -28,11 +28,11 @@ struct mci_slot_pdata {

/**
* struct mci_platform_data - board-specific MMC/SDcard configuration
- * @dma_slave: DMA slave interface to use in data transfers, or NULL.
+ * @dma_slave: DMA slave interface to use in data transfers.
* @slot: Per-slot configuration data.
*/
struct mci_platform_data {
- struct dma_slave *dma_slave;
+ struct dw_dma_slave dma_slave;
struct mci_slot_pdata slot[ATMEL_MCI_MAX_NR_SLOTS];
};

diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index 0c6e02f..359c01f 100644
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -1305,7 +1305,7 @@ struct platform_device *__init
at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
{
struct platform_device *pdev;
- struct dw_dma_slave *dws;
+ struct dw_dma_slave *dws = &data->dma_slave;
u32 pioa_mask;
u32 piob_mask;

@@ -1324,22 +1324,13 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
ARRAY_SIZE(atmel_mci0_resource)))
goto fail;

- if (data->dma_slave)
- dws = kmemdup(to_dw_dma_slave(data->dma_slave),
- sizeof(struct dw_dma_slave), GFP_KERNEL);
- else
- dws = kzalloc(sizeof(struct dw_dma_slave), GFP_KERNEL);
-
- dws->slave.dev = &pdev->dev;
- dws->slave.dma_dev = &dw_dmac0_device.dev;
- dws->slave.reg_width = DMA_SLAVE_WIDTH_32BIT;
+ dws->dma_dev = &dw_dmac0_device.dev;
+ dws->reg_width = DW_DMA_SLAVE_WIDTH_32BIT;
dws->cfg_hi = (DWC_CFGH_SRC_PER(0)
| DWC_CFGH_DST_PER(1));
dws->cfg_lo &= ~(DWC_CFGL_HS_DST_POL
| DWC_CFGL_HS_SRC_POL);

- data->dma_slave = &dws->slave;
-
if (platform_device_add_data(pdev, data,
sizeof(struct mci_platform_data)))
goto fail;
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 46fd5fa..1b694b8 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -223,10 +223,6 @@ static void dma_client_chan_alloc(struct dma_client *client)
list_for_each_entry(device, &dma_device_list, global_node) {
if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
continue;
- /* Does the client require a specific DMA controller? */
- if (client->slave && client->slave->dma_dev
- && client->slave->dma_dev != device->dev)
- continue;

list_for_each_entry(chan, &device->channels, device_node) {
if (!dma_chan_satisfies_mask(chan, client->cap_mask))
@@ -601,10 +597,6 @@ void dma_async_client_register(struct dma_client *client)
struct dma_chan *chan;
int err;

- /* validate client data */
- BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
- !client->slave);
-
mutex_lock(&dma_list_mutex);
dmaengine_ref_count++;

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 377dafa..dbd5080 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -567,7 +567,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (unlikely(!dws || !sg_len))
return NULL;

- reg_width = dws->slave.reg_width;
+ reg_width = dws->reg_width;
prev = first = NULL;

sg_len = dma_map_sg(chan->dev.parent, sgl, sg_len, direction);
@@ -579,7 +579,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| DWC_CTLL_DST_FIX
| DWC_CTLL_SRC_INC
| DWC_CTLL_FC_M2P);
- reg = dws->slave.tx_reg;
+ reg = dws->tx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len;
@@ -625,7 +625,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| DWC_CTLL_SRC_FIX
| DWC_CTLL_FC_P2M);

- reg = dws->slave.rx_reg;
+ reg = dws->rx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len;
@@ -764,7 +764,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc;
- struct dma_slave *slave;
struct dw_dma_slave *dws;
int i;
u32 cfghi;
@@ -772,12 +771,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,

dev_vdbg(&chan->dev, "alloc_chan_resources\n");

- /* Channels doing slave DMA can only handle one client. */
- if (dwc->dws || (client && client->slave)) {
- if (chan->client_count)
- return -EBUSY;
- }
-
/* ASSERT: channel is idle */
if (dma_readl(dw, CH_EN) & dwc->mask) {
dev_dbg(&chan->dev, "DMA channel not idle?\n");
@@ -789,23 +782,17 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
cfghi = DWC_CFGH_FIFO_MODE;
cfglo = 0;

- slave = client->slave;
- if (slave) {
+ dws = dwc->dws;
+ if (dws) {
/*
* We need controller-specific data to set up slave
* transfers.
*/
- BUG_ON(!slave->dma_dev || slave->dma_dev != dw->dma.dev);
-
- dws = container_of(slave, struct dw_dma_slave, slave);
+ BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);

- dwc->dws = dws;
cfghi = dws->cfg_hi;
cfglo = dws->cfg_lo;
- } else {
- dwc->dws = NULL;
}
-
channel_writel(dwc, CFG_LO, cfglo);
channel_writel(dwc, CFG_HI, cfghi);

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 6c11f4d..7a34118 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1441,60 +1441,6 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

-#ifdef CONFIG_MMC_ATMELMCI_DMA
-
-static inline struct atmel_mci *
-dma_client_to_atmel_mci(struct dma_client *client)
-{
- return container_of(client, struct atmel_mci, dma.client);
-}
-
-static enum dma_state_client atmci_dma_event(struct dma_client *client,
- struct dma_chan *chan, enum dma_state state)
-{
- struct atmel_mci *host;
- enum dma_state_client ret = DMA_NAK;
-
- host = dma_client_to_atmel_mci(client);
-
- switch (state) {
- case DMA_RESOURCE_AVAILABLE:
- spin_lock_bh(&host->lock);
- if (!host->dma.chan) {
- host->dma.chan = chan;
- ret = DMA_ACK;
- }
- spin_unlock_bh(&host->lock);
-
- if (ret == DMA_ACK)
- dev_info(&host->pdev->dev,
- "Using %s for DMA transfers\n",
- chan->dev.bus_id);
- break;
-
- case DMA_RESOURCE_REMOVED:
- spin_lock_bh(&host->lock);
- if (host->dma.chan == chan) {
- host->dma.chan = NULL;
- ret = DMA_ACK;
- }
- spin_unlock_bh(&host->lock);
-
- if (ret == DMA_ACK)
- dev_info(&host->pdev->dev,
- "Lost %s, falling back to PIO\n",
- chan->dev.bus_id);
- break;
-
- default:
- break;
- }
-
-
- return ret;
-}
-#endif /* CONFIG_MMC_ATMELMCI_DMA */
-
static int __init atmci_init_slot(struct atmel_mci *host,
struct mci_slot_pdata *slot_data, unsigned int id,
u32 sdc_reg)
@@ -1598,6 +1544,18 @@ static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
mmc_free_host(slot->mmc);
}

+#ifdef CONFIG_MMC_ATMELMCI_DMA
+static enum dma_state_client filter(struct dma_chan *chan, void *slave)
+{
+ struct dw_dma_slave *dws = slave;
+
+ if (dws->dma_dev == chan->device->dev)
+ return DMA_ACK;
+ else
+ return DMA_DUP;
+}
+#endif
+
static int __init atmci_probe(struct platform_device *pdev)
{
struct mci_platform_data *pdata;
@@ -1650,22 +1608,20 @@ static int __init atmci_probe(struct platform_device *pdev)
goto err_request_irq;

#ifdef CONFIG_MMC_ATMELMCI_DMA
- if (pdata->dma_slave) {
- struct dma_slave *slave = pdata->dma_slave;
+ if (pdata->dma_slave.dma_dev) {
+ struct dw_dma_slave *dws = &pdata->dma_slave;
+ dma_cap_mask_t mask;

- slave->tx_reg = regs->start + MCI_TDR;
- slave->rx_reg = regs->start + MCI_RDR;
+ dws->tx_reg = regs->start + MCI_TDR;
+ dws->rx_reg = regs->start + MCI_RDR;

/* Try to grab a DMA channel */
- host->dma.client.event_callback = atmci_dma_event;
- dma_cap_set(DMA_SLAVE, host->dma.client.cap_mask);
- host->dma.client.slave = slave;
-
- dma_async_client_register(&host->dma.client);
- dma_async_client_chan_request(&host->dma.client);
- } else {
- dev_notice(&pdev->dev, "DMA not available, using PIO\n");
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ host->dma.chan = dma_request_channel(mask, filter, dws);
}
+ if (!host->dma.chan)
+ dev_notice(&pdev->dev, "DMA not available, using PIO\n");
#endif /* CONFIG_MMC_ATMELMCI_DMA */

platform_set_drvdata(pdev, host);
@@ -1697,8 +1653,8 @@ static int __init atmci_probe(struct platform_device *pdev)

err_init_slot:
#ifdef CONFIG_MMC_ATMELMCI_DMA
- if (pdata->dma_slave)
- dma_async_client_unregister(&host->dma.client);
+ if (host->dma.chan)
+ dma_release_channel(host->dma.chan);
#endif
free_irq(irq, host);
err_request_irq:
@@ -1729,8 +1685,8 @@ static int __exit atmci_remove(struct platform_device *pdev)
clk_disable(host->mck);

#ifdef CONFIG_MMC_ATMELMCI_DMA
- if (host->dma.client.slave)
- dma_async_client_unregister(&host->dma.client);
+ if (host->dma.chan)
+ dma_release_channel(host->dma.chan);
#endif

free_irq(platform_get_irq(pdev, 0), host);
@@ -1759,7 +1715,7 @@ static void __exit atmci_exit(void)
platform_driver_unregister(&atmci_driver);
}

-module_init(atmci_init);
+late_initcall(atmci_init); /* try to load after dma driver when built-in */
module_exit(atmci_exit);

MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 6f2d070..d63544c 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -96,17 +96,6 @@ enum dma_transaction_type {
/* last transaction type for creation of the capabilities mask */
#define DMA_TX_TYPE_END (DMA_SLAVE + 1)

-/**
- * enum dma_slave_width - DMA slave register access width.
- * @DMA_SLAVE_WIDTH_8BIT: Do 8-bit slave register accesses
- * @DMA_SLAVE_WIDTH_16BIT: Do 16-bit slave register accesses
- * @DMA_SLAVE_WIDTH_32BIT: Do 32-bit slave register accesses
- */
-enum dma_slave_width {
- DMA_SLAVE_WIDTH_8BIT,
- DMA_SLAVE_WIDTH_16BIT,
- DMA_SLAVE_WIDTH_32BIT,
-};

/**
* enum dma_ctrl_flags - DMA flags to augment operation preparation,
@@ -133,32 +122,6 @@ enum dma_ctrl_flags {
typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;

/**
- * struct dma_slave - Information about a DMA slave
- * @dev: device acting as DMA slave
- * @dma_dev: required DMA master device. If non-NULL, the client can not be
- * bound to other masters than this.
- * @tx_reg: physical address of data register used for
- * memory-to-peripheral transfers
- * @rx_reg: physical address of data register used for
- * peripheral-to-memory transfers
- * @reg_width: peripheral register width
- *
- * If dma_dev is non-NULL, the client can not be bound to other DMA
- * masters than the one corresponding to this device. The DMA master
- * driver may use this to determine if there is controller-specific
- * data wrapped around this struct. Drivers of platform code that sets
- * the dma_dev field must therefore make sure to use an appropriate
- * controller-specific dma slave structure wrapping this struct.
- */
-struct dma_slave {
- struct device *dev;
- struct device *dma_dev;
- dma_addr_t tx_reg;
- dma_addr_t rx_reg;
- enum dma_slave_width reg_width;
-};
-
-/**
* struct dma_chan_percpu - the per-CPU part of struct dma_chan
* @refcount: local_t used for open-coded "bigref" counting
* @memcpy_count: transaction counter
@@ -248,7 +211,6 @@ typedef enum dma_state_client (*dma_filter_fn)(struct dma_chan *chan, void *filt
struct dma_client {
dma_event_callback event_callback;
dma_cap_mask_t cap_mask;
- struct dma_slave *slave;
struct list_head global_node;
};

diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h
index 04d217b..d797dde 100644
--- a/include/linux/dw_dmac.h
+++ b/include/linux/dw_dmac.h
@@ -22,14 +22,34 @@ struct dw_dma_platform_data {
};

/**
+ * enum dw_dma_slave_width - DMA slave register access width.
+ * @DMA_SLAVE_WIDTH_8BIT: Do 8-bit slave register accesses
+ * @DMA_SLAVE_WIDTH_16BIT: Do 16-bit slave register accesses
+ * @DMA_SLAVE_WIDTH_32BIT: Do 32-bit slave register accesses
+ */
+enum dw_dma_slave_width {
+ DW_DMA_SLAVE_WIDTH_8BIT,
+ DW_DMA_SLAVE_WIDTH_16BIT,
+ DW_DMA_SLAVE_WIDTH_32BIT,
+};
+
+/**
* struct dw_dma_slave - Controller-specific information about a slave
- * @slave: Generic information about the slave
- * @ctl_lo: Platform-specific initializer for the CTL_LO register
+ *
+ * @dma_dev: required DMA master device
+ * @tx_reg: physical address of data register used for
+ * memory-to-peripheral transfers
+ * @rx_reg: physical address of data register used for
+ * peripheral-to-memory transfers
+ * @reg_width: peripheral register width
* @cfg_hi: Platform-specific initializer for the CFG_HI register
* @cfg_lo: Platform-specific initializer for the CFG_LO register
*/
struct dw_dma_slave {
- struct dma_slave slave;
+ struct device *dma_dev;
+ dma_addr_t tx_reg;
+ dma_addr_t rx_reg;
+ enum dw_dma_slave_width reg_width;
u32 cfg_hi;
u32 cfg_lo;
};
@@ -54,9 +74,4 @@ struct dw_dma_slave {
#define DWC_CFGL_HS_DST_POL (1 << 18) /* dst handshake active low */
#define DWC_CFGL_HS_SRC_POL (1 << 19) /* src handshake active low */

-static inline struct dw_dma_slave *to_dw_dma_slave(struct dma_slave *slave)
-{
- return container_of(slave, struct dw_dma_slave, slave);
-}
-
#endif /* DW_DMAC_H */

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