linux/drivers/spi/spi-altera-platform.c
Russ Weight f09f6dfef8
spi: altera: Change to dynamic allocation of spi id
The spi-altera driver has two flavors: platform and dfl. I'm seeing
a case where I have both device types in the same machine, and they
are conflicting on the SPI ID:

... kernel: couldn't get idr
... kernel: WARNING: CPU: 28 PID: 912 at drivers/spi/spi.c:2920 spi_register_controller.cold+0x84/0xc0a

Both the platform and dfl drivers use the parent's driver ID as the SPI
ID. In the error case, the parent devices are dfl_dev.4 and
subdev_spi_altera.4.auto. When the second spi-master is created, the
failure occurs because the SPI ID of 4 has already been allocated.

Change the ID allocation to dynamic (by initializing bus_num to -1) to
avoid duplicate SPI IDs.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20211019002401.24041-1-russell.h.weight@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-10-20 01:53:15 +01:00

173 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Altera SPI driver
*
* Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
*
* Based on spi_s3c24xx.c, which is:
* Copyright (c) 2006 Ben Dooks
* Copyright (c) 2006 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*/
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/altera.h>
#include <linux/spi/spi.h>
#include <linux/io.h>
#include <linux/of.h>
#define DRV_NAME "spi_altera"
enum altera_spi_type {
ALTERA_SPI_TYPE_UNKNOWN,
ALTERA_SPI_TYPE_SUBDEV,
};
static const struct regmap_config spi_altera_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.fast_io = true,
};
static int altera_spi_probe(struct platform_device *pdev)
{
const struct platform_device_id *platid = platform_get_device_id(pdev);
struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
struct altera_spi *hw;
struct spi_master *master;
int err = -ENODEV;
u16 i;
master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
if (!master)
return err;
/* setup the master state. */
master->bus_num = -1;
if (pdata) {
if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
dev_err(&pdev->dev,
"Invalid number of chipselect: %u\n",
pdata->num_chipselect);
err = -EINVAL;
goto exit;
}
master->num_chipselect = pdata->num_chipselect;
master->mode_bits = pdata->mode_bits;
master->bits_per_word_mask = pdata->bits_per_word_mask;
} else {
master->num_chipselect = 16;
master->mode_bits = SPI_CS_HIGH;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
}
master->dev.of_node = pdev->dev.of_node;
hw = spi_master_get_devdata(master);
hw->dev = &pdev->dev;
if (platid)
type = platid->driver_data;
/* find and map our resources */
if (type == ALTERA_SPI_TYPE_SUBDEV) {
struct resource *regoff;
hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!hw->regmap) {
dev_err(&pdev->dev, "get regmap failed\n");
goto exit;
}
regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
if (regoff)
hw->regoff = regoff->start;
} else {
void __iomem *res;
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res)) {
err = PTR_ERR(res);
goto exit;
}
hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
&spi_altera_config);
if (IS_ERR(hw->regmap)) {
dev_err(&pdev->dev, "regmap mmio init failed\n");
err = PTR_ERR(hw->regmap);
goto exit;
}
}
altera_spi_init_master(master);
/* irq is optional */
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq >= 0) {
err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
pdev->name, master);
if (err)
goto exit;
}
err = devm_spi_register_master(&pdev->dev, master);
if (err)
goto exit;
if (pdata) {
for (i = 0; i < pdata->num_devices; i++) {
if (!spi_new_device(master, pdata->devices + i))
dev_warn(&pdev->dev,
"unable to create SPI device: %s\n",
pdata->devices[i].modalias);
}
}
dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
return 0;
exit:
spi_master_put(master);
return err;
}
#ifdef CONFIG_OF
static const struct of_device_id altera_spi_match[] = {
{ .compatible = "ALTR,spi-1.0", },
{ .compatible = "altr,spi-1.0", },
{},
};
MODULE_DEVICE_TABLE(of, altera_spi_match);
#endif /* CONFIG_OF */
static const struct platform_device_id altera_spi_ids[] = {
{ DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN },
{ "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV },
{ }
};
MODULE_DEVICE_TABLE(platform, altera_spi_ids);
static struct platform_driver altera_spi_driver = {
.probe = altera_spi_probe,
.driver = {
.name = DRV_NAME,
.pm = NULL,
.of_match_table = of_match_ptr(altera_spi_match),
},
.id_table = altera_spi_ids,
};
module_platform_driver(altera_spi_driver);
MODULE_DESCRIPTION("Altera SPI driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);