[RFC PATCH 2/7] DMA: tegra-apb: Move code dealing with h/w registers into separate functions
From: Jon Hunter
Date: Tue Aug 18 2015 - 09:51:50 EST
In preparation for adding the Tegra210 ADMA driver, that is based upon the
Tegra20-APB DMA driver, move code that accesses hardware registers into
specific functions. The Tegra210 ADMA and Tegra20-APB DMA drivers are not
compatible from a hardware register perspective, but the drivers are very
much the same. Hence, by isolating code that deals with the hardware
registers it will then be possible to add a function table to call code
that accesses the hardware registers and re-use the common driver code
for both DMAs.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/dma/tegra20-apb-dma.c | 277 ++++++++++++++++++++++++++----------------
1 file changed, 170 insertions(+), 107 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 097432ea89fa..e552a4efef71 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -359,6 +359,18 @@ static int tegra_dma_slave_config(struct dma_chan *dc,
return 0;
}
+static u32 tegra_dma_get_xfer_count(struct tegra_dma_channel *tdc)
+{
+ u32 wcount;
+
+ if (tdc->tdma->chip_data->support_separate_wcount_reg)
+ wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
+ else
+ wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
+
+ return (wcount & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
+}
+
static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
bool wait_for_burst_complete)
{
@@ -394,6 +406,38 @@ out:
spin_unlock(&tdma->global_lock);
}
+static u32 tegra_dma_irq_status(struct tegra_dma_channel *tdc)
+{
+ u32 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
+
+ return status & TEGRA_APBDMA_STATUS_ISE_EOC;
+}
+
+static u32 tegra_dma_irq_clear(struct tegra_dma_channel *tdc)
+{
+ u32 status = tegra_dma_irq_status(tdc);
+
+ if (status) {
+ dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
+ }
+
+ return status;
+}
+
+static void tegra_dma_program(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *nsg_req)
+{
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
+ if (tdc->tdma->chip_data->support_separate_wcount_reg)
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
+ nsg_req->ch_regs.wcount);
+ tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
+ nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
+ nsg_req->configured = true;
+}
+
static void tegra_dma_pause(struct tegra_dma_channel *tdc,
bool wait_for_burst_complete)
{
@@ -423,7 +467,6 @@ static void tegra_dma_resume(struct tegra_dma_channel *tdc)
static void tegra_dma_stop(struct tegra_dma_channel *tdc)
{
u32 csr;
- u32 status;
/* Disable interrupts */
csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
@@ -435,11 +478,8 @@ static void tegra_dma_stop(struct tegra_dma_channel *tdc)
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
/* Clear interrupt status if it is there */
- status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
- if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
- dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
- tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
- }
+ tegra_dma_irq_clear(tdc);
+
tdc->busy = false;
}
@@ -478,13 +518,13 @@ static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
* load new configuration.
*/
tegra_dma_pause(tdc, false);
- status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
+ status = tegra_dma_irq_status(tdc);
/*
* If interrupt is pending then do nothing as the ISR will handle
* the programing for new request.
*/
- if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
+ if (status) {
dev_err(tdc2dev(tdc),
"Skipping new configuration as interrupt is pending\n");
tegra_dma_resume(tdc);
@@ -492,15 +532,7 @@ static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
}
/* Safe to program new configuration */
- tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
- tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
- if (tdc->tdma->chip_data->support_separate_wcount_reg)
- tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
- nsg_req->ch_regs.wcount);
- tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
- nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
- nsg_req->configured = true;
-
+ tegra_dma_program(tdc, nsg_req);
tegra_dma_resume(tdc);
}
@@ -534,10 +566,10 @@ static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
}
}
-static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
- struct tegra_dma_sg_req *sg_req, unsigned long status)
+static inline int get_current_xferred_count(struct tegra_dma_sg_req *sg_req,
+ unsigned long wcount)
{
- return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
+ return sg_req->req_len - wcount;
}
static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
@@ -683,9 +715,8 @@ static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
spin_lock_irqsave(&tdc->lock, flags);
- status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
- if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
- tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
+ status = tegra_dma_irq_clear(tdc);
+ if (status) {
tdc->isr_handler(tdc, false);
tasklet_schedule(&tdc->tasklet);
spin_unlock_irqrestore(&tdc->lock, flags);
@@ -762,16 +793,13 @@ static int tegra_dma_terminate_all(struct dma_chan *dc)
/* Pause DMA before checking the queue status */
tegra_dma_pause(tdc, true);
- status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
- if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
+ status = tegra_dma_irq_status(tdc);
+ if (status) {
dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
tdc->isr_handler(tdc, true);
- status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
}
- if (tdc->tdma->chip_data->support_separate_wcount_reg)
- wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
- else
- wcount = status;
+
+ wcount = tegra_dma_get_xfer_count(tdc);
was_busy = tdc->busy;
tegra_dma_stop(tdc);
@@ -780,7 +808,7 @@ static int tegra_dma_terminate_all(struct dma_chan *dc)
sgreq = list_first_entry(&tdc->pending_sg_req,
typeof(*sgreq), node);
sgreq->dma_desc->bytes_transferred +=
- get_current_xferred_count(tdc, sgreq, wcount);
+ get_current_xferred_count(sgreq, wcount);
}
tegra_dma_resume(tdc);
@@ -865,11 +893,27 @@ static inline int get_bus_width(struct tegra_dma_channel *tdc,
}
static inline int get_burst_size(struct tegra_dma_channel *tdc,
- u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
+ enum dma_transfer_direction direction,
+ int len)
{
+ enum dma_slave_buswidth slave_bw;
+ u32 burst_size;
int burst_byte;
int burst_ahb_width;
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ burst_size = tdc->dma_sconfig.dst_maxburst;
+ slave_bw = tdc->dma_sconfig.dst_addr_width;
+ break;
+ case DMA_DEV_TO_MEM:
+ burst_size = tdc->dma_sconfig.src_maxburst;
+ slave_bw = tdc->dma_sconfig.src_addr_width;
+ break;
+ default:
+ return TEGRA_APBDMA_AHBSEQ_BURST_1;
+ }
+
/*
* burst_size from client is in terms of the bus_width.
* convert them into AHB memory width which is 4 byte.
@@ -894,29 +938,23 @@ static inline int get_burst_size(struct tegra_dma_channel *tdc,
return TEGRA_APBDMA_AHBSEQ_BURST_8;
}
-static int get_transfer_param(struct tegra_dma_channel *tdc,
- enum dma_transfer_direction direction, unsigned long *apb_addr,
- unsigned long *apb_seq, unsigned long *csr, unsigned int *burst_size,
- enum dma_slave_buswidth *slave_bw)
+static int tegra_dma_get_xfer_params(struct tegra_dma_channel *tdc,
+ struct tegra_dma_channel_regs *ch_regs,
+ enum dma_transfer_direction direction)
{
-
switch (direction) {
case DMA_MEM_TO_DEV:
- *apb_addr = tdc->dma_sconfig.dst_addr;
- *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
- *burst_size = tdc->dma_sconfig.dst_maxburst;
- *slave_bw = tdc->dma_sconfig.dst_addr_width;
- *csr = TEGRA_APBDMA_CSR_DIR;
+ ch_regs->apb_ptr = tdc->dma_sconfig.dst_addr;
+ ch_regs->apb_seq = get_bus_width(tdc,
+ tdc->dma_sconfig.dst_addr_width);
+ ch_regs->csr = TEGRA_APBDMA_CSR_DIR;
return 0;
-
case DMA_DEV_TO_MEM:
- *apb_addr = tdc->dma_sconfig.src_addr;
- *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
- *burst_size = tdc->dma_sconfig.src_maxburst;
- *slave_bw = tdc->dma_sconfig.src_addr_width;
- *csr = 0;
+ ch_regs->apb_ptr = tdc->dma_sconfig.src_addr;
+ ch_regs->apb_seq = get_bus_width(tdc,
+ tdc->dma_sconfig.src_addr_width);
+ ch_regs->csr = 0;
return 0;
-
default:
dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
return -EINVAL;
@@ -924,6 +962,60 @@ static int get_transfer_param(struct tegra_dma_channel *tdc,
return -EINVAL;
}
+static int tegra_dma_get_xfer_params_sg(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req,
+ enum dma_transfer_direction direction,
+ unsigned int flags)
+{
+ struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
+ int ret;
+
+ ret = tegra_dma_get_xfer_params(tdc, ch_regs, direction);
+ if (ret < 0)
+ return ret;
+
+ ch_regs->ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
+ ch_regs->ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
+ TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
+ ch_regs->ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
+
+ ch_regs->csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
+ ch_regs->csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
+ if (flags & DMA_PREP_INTERRUPT)
+ ch_regs->csr |= TEGRA_APBDMA_CSR_IE_EOC;
+
+ ch_regs->apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
+
+ return 0;
+}
+
+static int tegra_dma_get_xfer_params_cyclic(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req,
+ enum dma_transfer_direction direction,
+ unsigned int flags)
+{
+ struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
+ int ret;
+
+ ret = tegra_dma_get_xfer_params(tdc, ch_regs, direction);
+ if (ret < 0)
+ return ret;
+
+ ch_regs->ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
+ ch_regs->ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
+ TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
+ ch_regs->ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
+
+ ch_regs->csr |= TEGRA_APBDMA_CSR_FLOW;
+ if (flags & DMA_PREP_INTERRUPT)
+ ch_regs->csr |= TEGRA_APBDMA_CSR_IE_EOC;
+ ch_regs->csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
+
+ ch_regs->apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
+
+ return 0;
+}
+
static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
struct tegra_dma_channel_regs *ch_regs, u32 len)
{
@@ -935,6 +1027,24 @@ static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
ch_regs->csr |= len_field;
}
+static void tegra_dma_set_xfer_params(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req,
+ struct tegra_dma_sg_req *sg_base,
+ enum dma_transfer_direction direction,
+ u32 mem, u32 len)
+{
+ sg_req->ch_regs.ahb_seq |= get_burst_size(tdc, direction, len);
+ sg_req->ch_regs.apb_ptr = sg_base->ch_regs.apb_ptr;
+ sg_req->ch_regs.ahb_ptr = mem;
+ sg_req->ch_regs.csr = sg_base->ch_regs.csr;
+ tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
+ sg_req->ch_regs.apb_seq = sg_base->ch_regs.apb_seq;
+ sg_req->ch_regs.ahb_seq = sg_base->ch_regs.ahb_seq;
+ sg_req->configured = false;
+ sg_req->last_sg = false;
+ sg_req->req_len = len;
+}
+
static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
enum dma_transfer_direction direction, unsigned long flags,
@@ -942,13 +1052,10 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_desc *dma_desc;
- unsigned int i;
- struct scatterlist *sg;
- unsigned long csr, ahb_seq, apb_ptr, apb_seq;
+ unsigned int i;
+ struct scatterlist *sg;
struct list_head req_list;
- struct tegra_dma_sg_req *sg_req = NULL;
- u32 burst_size;
- enum dma_slave_buswidth slave_bw;
+ struct tegra_dma_sg_req sg_base, *sg_req = NULL;
if (!tdc->config_init) {
dev_err(tdc2dev(tdc), "dma channel is not configured\n");
@@ -959,24 +1066,11 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
return NULL;
}
- if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
- &burst_size, &slave_bw) < 0)
+ if (tegra_dma_get_xfer_params_sg(tdc, &sg_base, direction, flags) < 0)
return NULL;
INIT_LIST_HEAD(&req_list);
- ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
- ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
- TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
- ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
-
- csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
- csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
- if (flags & DMA_PREP_INTERRUPT)
- csr |= TEGRA_APBDMA_CSR_IE_EOC;
-
- apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
-
dma_desc = tegra_dma_desc_get(tdc);
if (!dma_desc) {
dev_err(tdc2dev(tdc), "Dma descriptors not available\n");
@@ -1011,19 +1105,11 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
return NULL;
}
- ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
dma_desc->bytes_requested += len;
- sg_req->ch_regs.apb_ptr = apb_ptr;
- sg_req->ch_regs.ahb_ptr = mem;
- sg_req->ch_regs.csr = csr;
- tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
- sg_req->ch_regs.apb_seq = apb_seq;
- sg_req->ch_regs.ahb_seq = ahb_seq;
- sg_req->configured = false;
- sg_req->last_sg = false;
+ tegra_dma_set_xfer_params(tdc, sg_req, &sg_base, direction,
+ mem, len);
sg_req->dma_desc = dma_desc;
- sg_req->req_len = len;
list_add_tail(&sg_req->node, &dma_desc->tx_list);
}
@@ -1056,13 +1142,10 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
{
struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
struct tegra_dma_desc *dma_desc = NULL;
- struct tegra_dma_sg_req *sg_req = NULL;
- unsigned long csr, ahb_seq, apb_ptr, apb_seq;
+ struct tegra_dma_sg_req sg_base, *sg_req = NULL;
int len;
size_t remain_len;
dma_addr_t mem = buf_addr;
- u32 burst_size;
- enum dma_slave_buswidth slave_bw;
if (!buf_len || !period_len) {
dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
@@ -1101,22 +1184,10 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
return NULL;
}
- if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
- &burst_size, &slave_bw) < 0)
+ if (tegra_dma_get_xfer_params_cyclic(tdc, &sg_base, direction,
+ flags) < 0)
return NULL;
- ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
- ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
- TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
- ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
-
- csr |= TEGRA_APBDMA_CSR_FLOW;
- if (flags & DMA_PREP_INTERRUPT)
- csr |= TEGRA_APBDMA_CSR_IE_EOC;
- csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
-
- apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
-
dma_desc = tegra_dma_desc_get(tdc);
if (!dma_desc) {
dev_err(tdc2dev(tdc), "not enough descriptors available\n");
@@ -1140,17 +1211,9 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
return NULL;
}
- ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
- sg_req->ch_regs.apb_ptr = apb_ptr;
- sg_req->ch_regs.ahb_ptr = mem;
- sg_req->ch_regs.csr = csr;
- tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
- sg_req->ch_regs.apb_seq = apb_seq;
- sg_req->ch_regs.ahb_seq = ahb_seq;
- sg_req->configured = false;
- sg_req->last_sg = false;
+ tegra_dma_set_xfer_params(tdc, sg_req, &sg_base, direction,
+ mem, len);
sg_req->dma_desc = dma_desc;
- sg_req->req_len = len;
list_add_tail(&sg_req->node, &dma_desc->tx_list);
remain_len -= len;
--
2.1.4
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