openwrt/target/linux/generic/pending-4.4/045-mtd-devices-m25p80-add-support-for-mmap-read-request.patch
John Crispin 74d00a8c38 kernel: split patches folder up into backport, pending and hack folders
* properly format/comment all patches
* merge debloat patches
* merge Kconfig patches
* merge swconfig patches
* merge hotplug patches
* drop 200-fix_localversion.patch - upstream
* drop 222-arm_zimage_none.patch - unused
* drop 252-mv_cesa_depends.patch - no longer required
* drop 410-mtd-move-forward-declaration-of-struct-mtd_info.patch - unused
* drop 661-fq_codel_keep_dropped_stats.patch - outdated
* drop 702-phy_add_aneg_done_function.patch - upstream
* drop 840-rtc7301.patch - unused
* drop 841-rtc_pt7c4338.patch - upstream
* drop 921-use_preinit_as_init.patch - unused
* drop spio-gpio-old and gpio-mmc - unused

Signed-off-by: John Crispin <john@phrozen.org>
2017-08-05 08:46:36 +02:00

47 lines
1.4 KiB
Diff

From 08922f644878c9163ada8df3ef9def89be1d5e90 Mon Sep 17 00:00:00 2001
From: Vignesh R <vigneshr@ti.com>
Date: Tue, 29 Mar 2016 11:16:17 +0530
Subject: [PATCH] mtd: devices: m25p80: add support for mmap read request
Certain SPI controllers may provide accelerated hardware interface to
read from m25p80 type flash devices in order to provide better read
performance. SPI core supports such devices with spi_flash_read() API.
Call spi_flash_read(), if supported, to make use of such interface.
Signed-off-by: Vignesh R <vigneshr@ti.com>
[Brian: add memset()]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -131,6 +131,28 @@ static int m25p80_read(struct spi_nor *n
/* convert the dummy cycles to the number of bytes */
dummy /= 8;
+ if (spi_flash_read_supported(spi)) {
+ struct spi_flash_read_message msg;
+ int ret;
+
+ memset(&msg, 0, sizeof(msg));
+
+ msg.buf = buf;
+ msg.from = from;
+ msg.len = len;
+ msg.read_opcode = nor->read_opcode;
+ msg.addr_width = nor->addr_width;
+ msg.dummy_bytes = dummy;
+ /* TODO: Support other combinations */
+ msg.opcode_nbits = SPI_NBITS_SINGLE;
+ msg.addr_nbits = SPI_NBITS_SINGLE;
+ msg.data_nbits = m25p80_rx_nbits(nor);
+
+ ret = spi_flash_read(spi, &msg);
+ *retlen = msg.retlen;
+ return ret;
+ }
+
spi_message_init(&m);
memset(t, 0, (sizeof t));