From 244b2c5ca8b14627e4a17755e5922221e121c771 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 09 Oct 2024 06:15:07 +0000
Subject: [PATCH] change system file
---
kernel/drivers/spi/spi-txx9.c | 78 +++++++++++++++++++++++++++++---------
1 files changed, 59 insertions(+), 19 deletions(-)
diff --git a/kernel/drivers/spi/spi-txx9.c b/kernel/drivers/spi/spi-txx9.c
index 51759d3..3606232 100644
--- a/kernel/drivers/spi/spi-txx9.c
+++ b/kernel/drivers/spi/spi-txx9.c
@@ -26,7 +26,8 @@
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
-#include <linux/gpio.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/consumer.h>
#define SPI_FIFO_SIZE 4
@@ -79,7 +80,7 @@
void __iomem *membase;
int baseclk;
struct clk *clk;
- int last_chipselect;
+ struct gpio_desc *last_chipselect;
int last_chipselect_val;
};
@@ -95,20 +96,22 @@
static void txx9spi_cs_func(struct spi_device *spi, struct txx9spi *c,
int on, unsigned int cs_delay)
{
- int val = (spi->mode & SPI_CS_HIGH) ? on : !on;
-
+ /*
+ * The GPIO descriptor will track polarity inversion inside
+ * gpiolib.
+ */
if (on) {
/* deselect the chip with cs_change hint in last transfer */
- if (c->last_chipselect >= 0)
- gpio_set_value(c->last_chipselect,
+ if (c->last_chipselect)
+ gpiod_set_value(c->last_chipselect,
!c->last_chipselect_val);
- c->last_chipselect = spi->chip_select;
- c->last_chipselect_val = val;
+ c->last_chipselect = spi->cs_gpiod;
+ c->last_chipselect_val = on;
} else {
- c->last_chipselect = -1;
+ c->last_chipselect = NULL;
ndelay(cs_delay); /* CS Hold Time */
}
- gpio_set_value(spi->chip_select, val);
+ gpiod_set_value(spi->cs_gpiod, on);
ndelay(cs_delay); /* CS Setup Time / CS Recovery Time */
}
@@ -118,12 +121,6 @@
if (!spi->max_speed_hz)
return -EINVAL;
-
- if (gpio_direction_output(spi->chip_select,
- !(spi->mode & SPI_CS_HIGH))) {
- dev_err(&spi->dev, "Cannot setup GPIO for chipselect.\n");
- return -EINVAL;
- }
/* deselect chip */
spin_lock(&c->lock);
@@ -248,8 +245,7 @@
len -= count * wsize;
}
m->actual_length += t->len;
- if (t->delay_usecs)
- udelay(t->delay_usecs);
+ spi_transfer_delay_exec(t);
if (!cs_change)
continue;
@@ -320,6 +316,47 @@
return 0;
}
+/*
+ * Chip select uses GPIO only, further the driver is using the chip select
+ * numer (from the device tree "reg" property, and this can only come from
+ * device tree since this i MIPS and there is no way to pass platform data) as
+ * the GPIO number. As the platform has only one GPIO controller (the txx9 GPIO
+ * chip) it is thus using the chip select number as an offset into that chip.
+ * This chip has a maximum of 16 GPIOs 0..15 and this is what all platforms
+ * register.
+ *
+ * We modernized this behaviour by explicitly converting that offset to an
+ * offset on the GPIO chip using a GPIO descriptor machine table of the same
+ * size as the txx9 GPIO chip with a 1-to-1 mapping of chip select to GPIO
+ * offset.
+ *
+ * This is admittedly a hack, but it is countering the hack of using "reg" to
+ * contain a GPIO offset when it should be using "cs-gpios" as the SPI bindings
+ * state.
+ */
+static struct gpiod_lookup_table txx9spi_cs_gpio_table = {
+ .dev_id = "spi0",
+ .table = {
+ GPIO_LOOKUP_IDX("TXx9", 0, "cs", 0, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 1, "cs", 1, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 2, "cs", 2, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 3, "cs", 3, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 4, "cs", 4, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 5, "cs", 5, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 6, "cs", 6, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 7, "cs", 7, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 8, "cs", 8, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 9, "cs", 9, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 10, "cs", 10, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 11, "cs", 11, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 12, "cs", 12, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 13, "cs", 13, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 14, "cs", 14, GPIO_ACTIVE_LOW),
+ GPIO_LOOKUP_IDX("TXx9", 15, "cs", 15, GPIO_ACTIVE_LOW),
+ { },
+ },
+};
+
static int txx9spi_probe(struct platform_device *dev)
{
struct spi_master *master;
@@ -373,11 +410,13 @@
if (ret)
goto exit;
- c->last_chipselect = -1;
+ c->last_chipselect = NULL;
dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n",
(unsigned long long)res->start, irq,
(c->baseclk + 500000) / 1000000);
+
+ gpiod_add_lookup_table(&txx9spi_cs_gpio_table);
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
@@ -387,6 +426,7 @@
master->transfer = txx9spi_transfer;
master->num_chipselect = (u16)UINT_MAX; /* any GPIO numbers */
master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
+ master->use_gpio_descriptors = true;
ret = devm_spi_register_master(&dev->dev, master);
if (ret)
--
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