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path: root/drivers/spi/spi-fsl-spi.c
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Diffstat (limited to 'drivers/spi/spi-fsl-spi.c')
-rw-r--r--drivers/spi/spi-fsl-spi.c89
1 files changed, 66 insertions, 23 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index 8f2e97857e8b..1d9b33aa1a3b 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Freescale SPI controller driver.
*
@@ -13,11 +14,6 @@
* GRLIB support:
* Copyright (c) 2012 Aeroflex Gaisler AB.
* Author: Andreas Larsson <andreas@gaisler.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
*/
#include <linux/delay.h>
#include <linux/dma-mapping.h>
@@ -39,6 +35,14 @@
#include <linux/spi/spi_bitbang.h>
#include <linux/types.h>
+#ifdef CONFIG_FSL_SOC
+#include <sysdev/fsl_soc.h>
+#endif
+
+/* Specific to the MPC8306/MPC8309 */
+#define IMMR_SPI_CS_OFFSET 0x14c
+#define SPI_BOOT_SEL_BIT 0x80000000
+
#include "spi-fsl-lib.h"
#include "spi-fsl-cpm.h"
#include "spi-fsl-spi.h"
@@ -355,33 +359,50 @@ static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
static int fsl_spi_do_one_msg(struct spi_master *master,
struct spi_message *m)
{
+ struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
struct spi_device *spi = m->spi;
struct spi_transfer *t, *first;
unsigned int cs_change;
const int nsecs = 50;
- int status;
+ int status, last_bpw;
+
+ /*
+ * In CPU mode, optimize large byte transfers to use larger
+ * bits_per_word values to reduce number of interrupts taken.
+ */
+ if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) {
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (t->len < 256 || t->bits_per_word != 8)
+ continue;
+ if ((t->len & 3) == 0)
+ t->bits_per_word = 32;
+ else if ((t->len & 1) == 0)
+ t->bits_per_word = 16;
+ }
+ }
/* Don't allow changes if CS is active */
- first = list_first_entry(&m->transfers, struct spi_transfer,
- transfer_list);
+ cs_change = 1;
list_for_each_entry(t, &m->transfers, transfer_list) {
- if ((first->bits_per_word != t->bits_per_word) ||
- (first->speed_hz != t->speed_hz)) {
+ if (cs_change)
+ first = t;
+ cs_change = t->cs_change;
+ if (first->speed_hz != t->speed_hz) {
dev_err(&spi->dev,
- "bits_per_word/speed_hz should be same for the same SPI transfer\n");
+ "speed_hz cannot change while CS is active\n");
return -EINVAL;
}
}
+ last_bpw = -1;
cs_change = 1;
status = -EINVAL;
list_for_each_entry(t, &m->transfers, transfer_list) {
- if (t->bits_per_word || t->speed_hz) {
- if (cs_change)
- status = fsl_spi_setup_transfer(spi, t);
- if (status < 0)
- break;
- }
+ if (cs_change || last_bpw != t->bits_per_word)
+ status = fsl_spi_setup_transfer(spi, t);
+ if (status < 0)
+ break;
+ last_bpw = t->bits_per_word;
if (cs_change) {
fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
@@ -407,7 +428,6 @@ static int fsl_spi_do_one_msg(struct spi_master *master,
}
m->status = status;
- spi_finalize_current_message(master);
if (status || !cs_change) {
ndelay(nsecs);
@@ -415,6 +435,7 @@ static int fsl_spi_do_one_msg(struct spi_master *master,
}
fsl_spi_setup_transfer(spi, NULL);
+ spi_finalize_current_message(master);
return 0;
}
@@ -701,10 +722,17 @@ static void fsl_spi_cs_control(struct spi_device *spi, bool on)
struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
u16 cs = spi->chip_select;
- int gpio = pinfo->gpios[cs];
- bool alow = pinfo->alow_flags[cs];
- gpio_set_value(gpio, on ^ alow);
+ if (cs < pinfo->ngpios) {
+ int gpio = pinfo->gpios[cs];
+ bool alow = pinfo->alow_flags[cs];
+
+ gpio_set_value(gpio, on ^ alow);
+ } else {
+ if (WARN_ON_ONCE(cs > pinfo->ngpios || !pinfo->immr_spi_cs))
+ return;
+ iowrite32be(on ? SPI_BOOT_SEL_BIT : 0, pinfo->immr_spi_cs);
+ }
}
static int of_fsl_spi_get_chipselects(struct device *dev)
@@ -712,12 +740,15 @@ static int of_fsl_spi_get_chipselects(struct device *dev)
struct device_node *np = dev->of_node;
struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
+ bool spisel_boot = IS_ENABLED(CONFIG_FSL_SOC) &&
+ of_property_read_bool(np, "fsl,spisel_boot");
int ngpios;
int i = 0;
int ret;
ngpios = of_gpio_count(np);
- if (ngpios <= 0) {
+ ngpios = max(ngpios, 0);
+ if (ngpios == 0 && !spisel_boot) {
/*
* SPI w/o chip-select line. One SPI device is still permitted
* though.
@@ -726,6 +757,7 @@ static int of_fsl_spi_get_chipselects(struct device *dev)
return 0;
}
+ pinfo->ngpios = ngpios;
pinfo->gpios = kmalloc_array(ngpios, sizeof(*pinfo->gpios),
GFP_KERNEL);
if (!pinfo->gpios)
@@ -769,7 +801,18 @@ static int of_fsl_spi_get_chipselects(struct device *dev)
}
}
- pdata->max_chipselect = ngpios;
+#if IS_ENABLED(CONFIG_FSL_SOC)
+ if (spisel_boot) {
+ pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4);
+ if (!pinfo->immr_spi_cs) {
+ ret = -ENOMEM;
+ i = ngpios - 1;
+ goto err_loop;
+ }
+ }
+#endif
+
+ pdata->max_chipselect = ngpios + spisel_boot;
pdata->cs_control = fsl_spi_cs_control;
return 0;