[PATCH 3/3] mtd: spi-nor: Altera Quadspi Flash Controller v2 Platform driver
matthew.gerlach at linux.intel.com
matthew.gerlach at linux.intel.com
Tue Jun 27 08:15:48 PDT 2017
On Tue, 27 Jun 2017, Marek Vasut wrote:
> On 06/26/2017 06:13 PM, matthew.gerlach at linux.intel.com wrote:
>> From: Matthew Gerlach <matthew.gerlach at linux.intel.com>
>
> Just wrap it into the Altera QSPI driver , no need for separate platform
> driver IMO.
Hi Marek,
I answered this question when you asked why the header file was necessary,
but I think further discussion could be helpful, since this problem is
becoming more prevelent. The Altera Quadspi component is a soft IP in a
FPGA, and the processor using the component may or may not have device
tree support compiled into the Linux kernel. Since device tree support
may or may not be available, the device tree specific code must be separated
from the core driver code.
One can certainly make the case, that device tree support could/should
be available everywhere, but the current reality is most x86 Linux
kernel configurations do not include device tree support.
For the record, I believe device trees, and more specifically device tree
overlays, are the best way for Linux to use FPGAs, but I have to deal with
the current realities.
Thanks again for all the great feedback.
Matthew Gerlach
>
>> Signed-off-by: Matthew Gerlach <matthew.gerlach at linux.intel.com>
>> ---
>> MAINTAINERS | 1 +
>> drivers/mtd/spi-nor/Kconfig | 5 +
>> drivers/mtd/spi-nor/Makefile | 1 +
>> drivers/mtd/spi-nor/altera-quadspi-platform.c | 137 ++++++++++++++++++++++++++
>> 4 files changed, 144 insertions(+)
>> create mode 100644 drivers/mtd/spi-nor/altera-quadspi-platform.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ae33fa6..c32bb98 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -653,6 +653,7 @@ M: Matthew Gerlach <matthew.gerlach at linux.intel.com>
>> L: linux-mtd at lists.infradead.org
>> S: Maintained
>> F: drivers/mtd/spi-nor/altera-quadspi.c
>> +F: drivers/mtd/spi-nor/altera-quadspi-platform.c
>> F: inclulde/linux/mtd/altera-quadspi.h
>>
>> ALTERA SYSTEM RESOURCE DRIVER FOR ARRIA10 DEVKIT
>> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
>> index 89fe425..f3d5c01 100644
>> --- a/drivers/mtd/spi-nor/Kconfig
>> +++ b/drivers/mtd/spi-nor/Kconfig
>> @@ -118,4 +118,9 @@ config SPI_ALTERA_QUADSPI
>> help
>> Enable support for version 2 of Altera Quad SPI Flash Controller.
>>
>> +config SPI_ALTERA_QUADSPI_PLATFORM
>> + tristate "Platform support for Altera Quad SPI Flash Controller II"
>> + help
>> + Platform driver support for Altera Quad SPI Flash Controller II"
>> +
>> endif # MTD_SPI_NOR
>> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
>> index 024c6ac..042f87e 100644
>> --- a/drivers/mtd/spi-nor/Makefile
>> +++ b/drivers/mtd/spi-nor/Makefile
>> @@ -10,4 +10,5 @@ obj-$(CONFIG_SPI_INTEL_SPI) += intel-spi.o
>> obj-$(CONFIG_SPI_INTEL_SPI_PLATFORM) += intel-spi-platform.o
>> obj-$(CONFIG_SPI_STM32_QUADSPI) += stm32-quadspi.o
>> obj-$(CONFIG_SPI_ALTERA_QUADSPI) += altera-quadspi.o
>> +obj-$(CONFIG_SPI_ALTERA_QUADSPI_PLATFORM) += altera-quadspi-platform.o
>>
>> diff --git a/drivers/mtd/spi-nor/altera-quadspi-platform.c b/drivers/mtd/spi-nor/altera-quadspi-platform.c
>> new file mode 100644
>> index 0000000..c8d2a47
>> --- /dev/null
>> +++ b/drivers/mtd/spi-nor/altera-quadspi-platform.c
>> @@ -0,0 +1,137 @@
>> +/*
>> + * Copyright (C) 2014 Altera Corporation. All rights reserved.
>> + * Copyright (C) 2017 Intel Corporation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/mtd/altera-quadspi.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_device.h>
>> +
>> +static int altera_quadspi_probe(struct platform_device *pdev)
>> +{
>> + struct device_node *np = pdev->dev.of_node;
>> + struct device *dev = &pdev->dev;
>> + struct resource *res;
>> + void __iomem *csr_base;
>> + void __iomem *data_base;
>> + void __iomem *window_base = NULL;
>> + u32 window_size = 0;
>> + u32 flags = 0;
>> + u32 bank;
>> + int ret;
>> + struct device_node *pp;
>> +
>> + if (!np) {
>> + dev_err(dev, "no device found\n");
>> + return -ENODEV;
>> + }
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "avl_csr");
>> + csr_base = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(csr_base)) {
>> + dev_err(dev, "%s: ERROR: failed to map csr base\n", __func__);
>> + return PTR_ERR(csr_base);
>> + }
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "avl_mem");
>> + data_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(data_base)) {
>> + dev_err(dev, "%s: ERROR: failed to map data base\n", __func__);
>> + return PTR_ERR(data_base);
>> + }
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "avl_window");
>> + if (res) {
>> + window_base = NULL;
>> + window_base = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(window_base)) {
>> + dev_err(dev, "%s: ERROR: failed to map window base\n",
>> + __func__);
>> + return PTR_ERR(data_base);
>> + }
>> +
>> + of_property_read_u32(dev->of_node, "window-size", &window_size);
>> +
>> + if (!window_size) {
>> + dev_err(dev,
>> + "alv_window defined, %s",
>> + "but no window-size defined\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + if (of_property_read_bool(np, "read-bit-reverse"))
>> + flags |= ALTERA_QUADSPI_FL_BITREV_READ;
>> +
>> + if (of_property_read_bool(np, "write-bit-reverse"))
>> + flags |= ALTERA_QUADSPI_FL_BITREV_WRITE;
>> +
>> + ret = altera_quadspi_create(dev, csr_base, data_base,
>> + window_base, (size_t)window_size, flags);
>> +
>> + if (ret) {
>> + dev_err(dev, "failed to create qspi device\n");
>> + return ret;
>> + }
>> +
>> + for_each_available_child_of_node(np, pp) {
>> + of_property_read_u32(pp, "reg", &bank);
>> + if (bank >= ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP) {
>> + dev_err(dev, "bad reg value %u >= %u\n", bank,
>> + ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP);
>> + goto error;
>> + }
>> +
>> + if (altera_qspi_add_bank(dev, bank, pp)) {
>> + dev_err(dev, "failed to add bank %u\n", bank);
>> + goto error;
>> + }
>> + }
>> +
>> + return 0;
>> +error:
>> + altera_quadspi_remove_banks(dev);
>> + return -EIO;
>> +}
>> +
>> +static int altera_quadspi_remove(struct platform_device *pdev)
>> +{
>> + return altera_quadspi_remove_banks(&pdev->dev);
>> +}
>> +
>> +static const struct of_device_id altera_quadspi_id_table[] = {
>> +
>> + { .compatible = "altr,quadspi-v2",},
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, altera_quadspi_id_table);
>> +
>> +static struct platform_driver altera_quadspi_driver = {
>> + .driver = {
>> + .name = "altera_quadspi_platform",
>> + .of_match_table = altera_quadspi_id_table,
>> + },
>> + .probe = altera_quadspi_probe,
>> + .remove = altera_quadspi_remove,
>> +};
>> +module_platform_driver(altera_quadspi_driver);
>> +
>> +MODULE_AUTHOR("Viet Nga Dao <vndao at altera.com>");
>> +MODULE_AUTHOR("Yong Sern Lau <lau.yong.sern at intel.com>");
>> +MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach at linux.intel.com>");
>> +MODULE_DESCRIPTION("Altera QuadSPI Version 2 Platform Driver");
>> +MODULE_LICENSE("GPL v2");
>>
>
>
> --
> Best regards,
> Marek Vasut
>
More information about the linux-mtd
mailing list