fpga: xilinx-selectmap: add new driver

Xilinx 7 series FPGA can be programmed using a parallel port named
the SelectMAP interface in the datasheet. This interface is compatible
with the i.MX6 EIM bus controller but other types of external memory
mapped parallel bus might work.

xilinx-selectmap currently only supports the x8 mode where data is loaded
at one byte per rising edge of the clock, with the MSb of each byte
presented to the D0 pin.

Signed-off-by: Charles Perry <charles.perry@savoirfairelinux.com>
[yilun.xu@linux.intel.com: replace data type of i from u32 to size_t]
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20240321220447.3260065-4-charles.perry@savoirfairelinux.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index d27a1ebf4083821811cfc69ac297bf368f3da8b5..37b35f58f0dfb6209c2d1419bc9145237dfaea0b 100644 (file)
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -67,6 +67,14 @@ config FPGA_MGR_STRATIX10_SOC
 config FPGA_MGR_XILINX_CORE
        tristate
 
+config FPGA_MGR_XILINX_SELECTMAP
+       tristate "Xilinx Configuration over SelectMAP"
+       depends on HAS_IOMEM
+       select FPGA_MGR_XILINX_CORE
+       help
+         FPGA manager driver support for Xilinx FPGA configuration
+         over SelectMAP interface.
+
 config FPGA_MGR_XILINX_SPI
        tristate "Xilinx Configuration over Slave Serial (SPI)"
        depends on SPI

diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 7ec795b6a5a7081889fecb9fab49f55164a0e567..aeb89bb13517e471b143c2e3a6801be9f46116bd 100644 (file)
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)    += socfpga-a10.o
 obj-$(CONFIG_FPGA_MGR_STRATIX10_SOC)   += stratix10-soc.o
 obj-$(CONFIG_FPGA_MGR_TS73XX)          += ts73xx-fpga.o
 obj-$(CONFIG_FPGA_MGR_XILINX_CORE)     += xilinx-core.o
+obj-$(CONFIG_FPGA_MGR_XILINX_SELECTMAP)        += xilinx-selectmap.o
 obj-$(CONFIG_FPGA_MGR_XILINX_SPI)      += xilinx-spi.o
 obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)       += zynq-fpga.o
 obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)     += zynqmp-fpga.o

diff --git a/drivers/fpga/xilinx-selectmap.c b/drivers/fpga/xilinx-selectmap.c
new file mode 100644 (file)
index 0000000..2cd87e7
--- /dev/null
+++ b/drivers/fpga/xilinx-selectmap.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Xilinx Spartan6 and 7 Series SelectMAP interface driver
+ *
+ * (C) 2024 Charles Perry <charles.perry@savoirfairelinux.com>
+ *
+ * Manage Xilinx FPGA firmware loaded over the SelectMAP configuration
+ * interface.
+ */
+
+#include "xilinx-core.h"
+
+#include <linux/gpio/consumer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+struct xilinx_selectmap_conf {
+       struct xilinx_fpga_core core;
+       void __iomem *base;
+};
+
+#define to_xilinx_selectmap_conf(obj) \
+       container_of(obj, struct xilinx_selectmap_conf, core)
+
+static int xilinx_selectmap_write(struct xilinx_fpga_core *core,
+                                 const char *buf, size_t count)
+{
+       struct xilinx_selectmap_conf *conf = to_xilinx_selectmap_conf(core);
+       size_t i;
+
+       for (i = 0; i < count; ++i)
+               writeb(buf[i], conf->base);
+
+       return 0;
+}
+
+static int xilinx_selectmap_probe(struct platform_device *pdev)
+{
+       struct xilinx_selectmap_conf *conf;
+       struct gpio_desc *gpio;
+       void __iomem *base;
+
+       conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
+       if (!conf)
+               return -ENOMEM;
+
+       conf->core.dev = &pdev->dev;
+       conf->core.write = xilinx_selectmap_write;
+
+       base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+       if (IS_ERR(base))
+               return dev_err_probe(&pdev->dev, PTR_ERR(base),
+                                    "ioremap error\n");
+       conf->base = base;
+
+       /* CSI_B is active low */
+       gpio = devm_gpiod_get_optional(&pdev->dev, "csi", GPIOD_OUT_HIGH);
+       if (IS_ERR(gpio))
+               return dev_err_probe(&pdev->dev, PTR_ERR(gpio),
+                                    "Failed to get CSI_B gpio\n");
+
+       /* RDWR_B is active low */
+       gpio = devm_gpiod_get_optional(&pdev->dev, "rdwr", GPIOD_OUT_HIGH);
+       if (IS_ERR(gpio))
+               return dev_err_probe(&pdev->dev, PTR_ERR(gpio),
+                                    "Failed to get RDWR_B gpio\n");
+
+       return xilinx_core_probe(&conf->core);
+}
+
+static const struct of_device_id xlnx_selectmap_of_match[] = {
+       { .compatible = "xlnx,fpga-xc7s-selectmap", }, // Spartan-7
+       { .compatible = "xlnx,fpga-xc7a-selectmap", }, // Artix-7
+       { .compatible = "xlnx,fpga-xc7k-selectmap", }, // Kintex-7
+       { .compatible = "xlnx,fpga-xc7v-selectmap", }, // Virtex-7
+       {},
+};
+MODULE_DEVICE_TABLE(of, xlnx_selectmap_of_match);
+
+static struct platform_driver xilinx_selectmap_driver = {
+       .driver = {
+               .name = "xilinx-selectmap",
+               .of_match_table = xlnx_selectmap_of_match,
+       },
+       .probe  = xilinx_selectmap_probe,
+};
+
+module_platform_driver(xilinx_selectmap_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Charles Perry <charles.perry@savoirfairelinux.com>");
+MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SelectMap");