Commit c627230d authored by Sudhakar Rajashekhara's avatar Sudhakar Rajashekhara Committed by Kevin Hilman

davinci: MMC: Pass number of SG segments as platform data

On some platforms like DM355, the number of EDMA parameter
slots available for EDMA_SLOT_ANY usage are few. In such cases,
if MMC/SD uses 16 slots for each instance of MMC controller,
then the number of slots available for other modules will be
very few.

By passing the number of EDMA slots to be used in MMC driver
from platform data, EDMA slots available for other purposes
can be controlled.
Signed-off-by: default avatarSudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
parent e40152ee
...@@ -22,6 +22,9 @@ struct davinci_mmc_config { ...@@ -22,6 +22,9 @@ struct davinci_mmc_config {
/* Version of the MMC/SD controller */ /* Version of the MMC/SD controller */
u8 version; u8 version;
/* Number of sg segments */
u8 nr_sg;
}; };
void davinci_setup_mmc(int module, struct davinci_mmc_config *config); void davinci_setup_mmc(int module, struct davinci_mmc_config *config);
......
...@@ -137,15 +137,15 @@ ...@@ -137,15 +137,15 @@
/* /*
* One scatterlist dma "segment" is at most MAX_CCNT rw_threshold units, * One scatterlist dma "segment" is at most MAX_CCNT rw_threshold units,
* and we handle up to NR_SG segments. MMC_BLOCK_BOUNCE kicks in only * and we handle up to MAX_NR_SG segments. MMC_BLOCK_BOUNCE kicks in only
* for drivers with max_hw_segs == 1, making the segments bigger (64KB) * for drivers with max_hw_segs == 1, making the segments bigger (64KB)
* than the page or two that's otherwise typical. NR_SG == 16 gives at * than the page or two that's otherwise typical. nr_sg (passed from
* least the same throughput boost, using EDMA transfer linkage instead * platform data) == 16 gives at least the same throughput boost, using
* of spending CPU time copying pages. * EDMA transfer linkage instead of spending CPU time copying pages.
*/ */
#define MAX_CCNT ((1 << 16) - 1) #define MAX_CCNT ((1 << 16) - 1)
#define NR_SG 16 #define MAX_NR_SG 16
static unsigned rw_threshold = 32; static unsigned rw_threshold = 32;
module_param(rw_threshold, uint, S_IRUGO); module_param(rw_threshold, uint, S_IRUGO);
...@@ -192,7 +192,7 @@ struct mmc_davinci_host { ...@@ -192,7 +192,7 @@ struct mmc_davinci_host {
struct edmacc_param tx_template; struct edmacc_param tx_template;
struct edmacc_param rx_template; struct edmacc_param rx_template;
unsigned n_link; unsigned n_link;
u32 links[NR_SG - 1]; u32 links[MAX_NR_SG - 1];
/* For PIO we walk scatterlists one segment at a time. */ /* For PIO we walk scatterlists one segment at a time. */
unsigned int sg_len; unsigned int sg_len;
...@@ -202,6 +202,8 @@ struct mmc_davinci_host { ...@@ -202,6 +202,8 @@ struct mmc_davinci_host {
u8 version; u8 version;
/* for ns in one cycle calculation */ /* for ns in one cycle calculation */
unsigned ns_in_one_cycle; unsigned ns_in_one_cycle;
/* Number of sg segments */
u8 nr_sg;
#ifdef CONFIG_CPU_FREQ #ifdef CONFIG_CPU_FREQ
struct notifier_block freq_transition; struct notifier_block freq_transition;
#endif #endif
...@@ -568,6 +570,7 @@ davinci_release_dma_channels(struct mmc_davinci_host *host) ...@@ -568,6 +570,7 @@ davinci_release_dma_channels(struct mmc_davinci_host *host)
static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host) static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host)
{ {
u32 link_size;
int r, i; int r, i;
/* Acquire master DMA write channel */ /* Acquire master DMA write channel */
...@@ -593,7 +596,8 @@ static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host) ...@@ -593,7 +596,8 @@ static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host)
/* Allocate parameter RAM slots, which will later be bound to a /* Allocate parameter RAM slots, which will later be bound to a
* channel as needed to handle a scatterlist. * channel as needed to handle a scatterlist.
*/ */
for (i = 0; i < ARRAY_SIZE(host->links); i++) { link_size = min_t(unsigned, host->nr_sg, ARRAY_SIZE(host->links));
for (i = 0; i < link_size; i++) {
r = edma_alloc_slot(EDMA_CTLR(host->txdma), EDMA_SLOT_ANY); r = edma_alloc_slot(EDMA_CTLR(host->txdma), EDMA_SLOT_ANY);
if (r < 0) { if (r < 0) {
dev_dbg(mmc_dev(host->mmc), "dma PaRAM alloc --> %d\n", dev_dbg(mmc_dev(host->mmc), "dma PaRAM alloc --> %d\n",
...@@ -1202,6 +1206,12 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev) ...@@ -1202,6 +1206,12 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
init_mmcsd_host(host); init_mmcsd_host(host);
if (pdata->nr_sg)
host->nr_sg = pdata->nr_sg - 1;
if (host->nr_sg > MAX_NR_SG || !host->nr_sg)
host->nr_sg = MAX_NR_SG;
host->use_dma = use_dma; host->use_dma = use_dma;
host->irq = irq; host->irq = irq;
......
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