staging: fbtft: remove custom DMA mapped buffer

There is no need to duplicate what SPI core already does, i.e. mapping buffers
for DMA capable transfers.

Remove all related pices of code.

Note, that code, besides its redundancy, was buggy: DMA address potentially can
be 0, SPI slave device has nothing to do with DMA capable device properties and
DMA mask in particular.

Suggested-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andy Shevchenko 2017-01-19 12:45:42 +02:00 committed by Greg Kroah-Hartman
parent 9ed2bfb3e3
commit 7c3eaadd02
4 changed files with 2 additions and 29 deletions

View file

@ -42,10 +42,6 @@ static int write_spi(struct fbtft_par *par, void *buf, size_t len)
}
spi_message_init(&m);
if (par->txbuf.dma && buf == par->txbuf.buf) {
t.tx_dma = par->txbuf.dma;
m.is_dma_mapped = 1;
}
spi_message_add_tail(&t, &m);
return spi_sync(par->spi, &m);
}

View file

@ -32,7 +32,6 @@
#include <linux/backlight.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <video/mipi_display.h>
@ -44,12 +43,6 @@ static unsigned long debug;
module_param(debug, ulong, 0);
MODULE_PARM_DESC(debug, "override device debug level");
#ifdef CONFIG_HAS_DMA
static bool dma = true;
module_param(dma, bool, 0);
MODULE_PARM_DESC(dma, "Use DMA buffer");
#endif
void fbtft_dbg_hex(const struct device *dev, int groupsize,
void *buf, size_t len, const char *fmt, ...)
{
@ -836,17 +829,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
#endif
if (txbuflen > 0) {
#ifdef CONFIG_HAS_DMA
if (dma) {
dev->coherent_dma_mask = ~0;
txbuf = dmam_alloc_coherent(dev, txbuflen,
&par->txbuf.dma, GFP_DMA);
} else
#endif
{
txbuf = devm_kzalloc(par->info->device,
txbuflen, GFP_KERNEL);
}
txbuf = devm_kzalloc(par->info->device, txbuflen, GFP_KERNEL);
if (!txbuf)
goto alloc_fail;
par->txbuf.buf = txbuf;
@ -975,8 +958,7 @@ int fbtft_register_framebuffer(struct fb_info *fb_info)
fbtft_sysfs_init(par);
if (par->txbuf.buf)
sprintf(text1, ", %zu KiB %sbuffer memory",
par->txbuf.len >> 10, par->txbuf.dma ? "DMA " : "");
sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
if (spi)
sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
spi->chip_select, spi->max_speed_hz / 1000000);

View file

@ -22,10 +22,6 @@ int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len)
}
spi_message_init(&m);
if (par->txbuf.dma && buf == par->txbuf.buf) {
t.tx_dma = par->txbuf.dma;
m.is_dma_mapped = 1;
}
spi_message_add_tail(&t, &m);
return spi_sync(par->spi, &m);
}

View file

@ -209,7 +209,6 @@ struct fbtft_par {
u32 pseudo_palette[16];
struct {
void *buf;
dma_addr_t dma;
size_t len;
} txbuf;
u8 *buf;