openwrt/target/linux/ath79/patches-4.19/410-spi-ath79-Implement-the-spi_mem-interface.patch
Luiz Angelo Daros de Luca b3f9842330 ath79: add read support using spi-mem
Reimplements read optimization on top of spi-mem. Similar to
what 461-spi-ath79-add-fast-flash-read.patch used to do with
the dropped flash read interface.

It accelerate only fast-read op reading flash directly from
memory mapped region. 'm25p,fast-read' must be set in order
to use the new spi-mem.

It improved read speed up to 3x on old devices (tplink,tl-wr2543-v1)
while no speed improvement was noticed on newer devices like
(tplink,archer-c7-v2).

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
2020-04-14 10:47:23 +08:00

71 lines
2.2 KiB
Diff

From 8d8cdb4a6ccee5b62cc0dc64651c3946364514dc Mon Sep 17 00:00:00 2001
From: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Date: Mon, 10 Feb 2020 16:11:27 -0300
Subject: [PATCH] spi: ath79: Implement the spi_mem interface
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
drivers/spi/spi-ath79.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
Index: linux-4.19.106/drivers/spi/spi-ath79.c
===================================================================
--- linux-4.19.106.orig/drivers/spi/spi-ath79.c
+++ linux-4.19.106/drivers/spi/spi-ath79.c
@@ -19,6 +19,7 @@
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/bitops.h>
#include <linux/gpio.h>
@@ -203,6 +204,39 @@ static u32 ath79_spi_txrx_mode0(struct s
return ath79_spi_rr(sp, AR71XX_SPI_REG_RDS);
}
+static int ath79_exec_mem_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ struct ath79_spi *sp = ath79_spidev_to_sp(mem->spi);
+
+ /* Ensures that reading is performed on device connected
+ to hardware cs0 */
+ if (mem->spi->chip_select || gpio_is_valid(mem->spi->cs_gpio))
+ return -ENOTSUPP;
+
+ /* Only use for fast-read op. */
+ if (op->cmd.opcode != 0x0b || op->data.dir != SPI_MEM_DATA_IN ||
+ op->addr.nbytes != 3 || op->dummy.nbytes != 1)
+ return -ENOTSUPP;
+
+ /* disable GPIO mode */
+ ath79_spi_wr(sp, AR71XX_SPI_REG_FS, 0);
+
+ memcpy_fromio(op->data.buf.in, sp->base + op->addr.val, op->data.nbytes);
+
+ /* enable GPIO mode */
+ ath79_spi_wr(sp, AR71XX_SPI_REG_FS, AR71XX_SPI_FS_GPIO);
+
+ /* restore IOC register */
+ ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, sp->ioc_base);
+
+ return 0;
+}
+
+static const struct spi_controller_mem_ops ath79_mem_ops = {
+ .exec_op = ath79_exec_mem_op,
+};
+
static int ath79_spi_probe(struct platform_device *pdev)
{
struct spi_master *master;
@@ -237,6 +271,7 @@ static int ath79_spi_probe(struct platfo
ret = PTR_ERR(sp->base);
goto err_put_master;
}
+ master->mem_ops = &ath79_mem_ops;
sp->clk = devm_clk_get(&pdev->dev, "ahb");
if (IS_ERR(sp->clk)) {