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From a7b221d8f0d75511c5f959584712a5dd35f88a86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Mon, 18 Apr 2016 14:39:30 +0200
Subject: [PATCH] spi: bcm53xx: add spi_flash_read callback for MMIO-based
reads
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This implements more efficient reads of SPI-attached flash content.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
--- a/drivers/spi/spi-bcm53xx.c
+++ b/drivers/spi/spi-bcm53xx.c
@@ -10,6 +10,7 @@
#include "spi-bcm53xx.h"
#define BCM53XXSPI_MAX_SPI_BAUD 13500000 /* 216 MHz? */
+#define BCM53XXSPI_FLASH_WINDOW SZ_32M
/* The longest observed required wait was 19 ms */
#define BCM53XXSPI_SPE_TIMEOUT_MS 80
@@ -17,8 +18,10 @@
struct bcm53xxspi {
struct bcma_device *core;
struct spi_master *master;
+ void __iomem *mmio_base;
size_t read_offset;
+ bool bspi; /* Boot SPI mode with memory mapping */
};
static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset)
@@ -32,6 +35,50 @@ static inline void bcm53xxspi_write(stru
bcma_write32(b53spi->core, offset, value);
}
+static void bcm53xxspi_disable_bspi(struct bcm53xxspi *b53spi)
+{
+ struct device *dev = &b53spi->core->dev;
+ unsigned long deadline;
+ u32 tmp;
+
+ if (!b53spi->bspi)
+ return;
+
+ tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL);
+ if (tmp & 0x1)
+ return;
+
+ deadline = jiffies + usecs_to_jiffies(200);
+ do {
+ tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_BUSY_STATUS);
+ if (!(tmp & 0x1)) {
+ bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL,
+ 0x1);
+ ndelay(200);
+ b53spi->bspi = false;
+ return;
+ }
+ udelay(1);
+ } while (!time_after_eq(jiffies, deadline));
+
+ dev_warn(dev, "Timeout disabling BSPI\n");
+}
+
+static void bcm53xxspi_enable_bspi(struct bcm53xxspi *b53spi)
+{
+ u32 tmp;
+
+ if (b53spi->bspi)
+ return;
+
+ tmp = bcm53xxspi_read(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL);
+ if (!(tmp & 0x1))
+ return;
+
+ bcm53xxspi_write(b53spi, B53SPI_BSPI_MAST_N_BOOT_CTRL, 0x0);
+ b53spi->bspi = true;
+}
+
static inline unsigned int bcm53xxspi_calc_timeout(size_t len)
{
/* Do some magic calculation based on length and buad. Add 10% and 1. */
@@ -176,6 +223,8 @@ static int bcm53xxspi_transfer_one(struc
u8 *buf;
size_t left;
+ bcm53xxspi_disable_bspi(b53spi);
+
if (t->tx_buf) {
buf = (u8 *)t->tx_buf;
left = t->len;
@@ -206,6 +255,22 @@ static int bcm53xxspi_transfer_one(struc
return 0;
}
+static int bcm53xxspi_flash_read(struct spi_device *spi,
+ struct spi_flash_read_message *msg)
+{
+ struct bcm53xxspi *b53spi = spi_master_get_devdata(spi->master);
+ int ret = 0;
+
+ if (msg->from + msg->len > BCM53XXSPI_FLASH_WINDOW)
+ return -EINVAL;
+
+ bcm53xxspi_enable_bspi(b53spi);
+ memcpy_fromio(msg->buf, b53spi->mmio_base + msg->from, msg->len);
+ msg->retlen = msg->len;
+
+ return ret;
+}
+
/**************************************************
* BCMA
**************************************************/
@@ -222,6 +287,7 @@ MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcm
static int bcm53xxspi_bcma_probe(struct bcma_device *core)
{
+ struct device *dev = &core->dev;
struct bcm53xxspi *b53spi;
struct spi_master *master;
int err;
@@ -231,7 +297,7 @@ static int bcm53xxspi_bcma_probe(struct
return -ENOTSUPP;
}
- master = spi_alloc_master(&core->dev, sizeof(*b53spi));
+ master = spi_alloc_master(dev, sizeof(*b53spi));
if (!master)
return -ENOMEM;
@@ -239,11 +305,19 @@ static int bcm53xxspi_bcma_probe(struct
b53spi->master = master;
b53spi->core = core;
+ if (core->addr_s[0])
+ b53spi->mmio_base = devm_ioremap(dev, core->addr_s[0],
+ BCM53XXSPI_FLASH_WINDOW);
+ b53spi->bspi = true;
+ bcm53xxspi_disable_bspi(b53spi);
+
master->transfer_one = bcm53xxspi_transfer_one;
+ if (b53spi->mmio_base)
+ master->spi_flash_read = bcm53xxspi_flash_read;
bcma_set_drvdata(core, b53spi);
- err = devm_spi_register_master(&core->dev, master);
+ err = devm_spi_register_master(dev, master);
if (err) {
spi_master_put(master);
bcma_set_drvdata(core, NULL);
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