drivers/fpga/xilinx-selectmap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Xilinx Spartan6 and 7 Series SelectMAP interface driver
   4  *
   5  * (C) 2024 Charles Perry <charles.perry@savoirfairelinux.com>
   6  *
   7  * Manage Xilinx FPGA firmware loaded over the SelectMAP configuration
   8  * interface.
   9  */
  10
  11 #include "xilinx-core.h"
  12
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/mod_devicetable.h>
  17 #include <linux/of.h>
  18 #include <linux/platform_device.h>
  19
  20 struct xilinx_selectmap_conf {
  21         struct xilinx_fpga_core core;
  22         void __iomem *base;
  23 };
  24
  25 #define to_xilinx_selectmap_conf(obj) \
  26         container_of(obj, struct xilinx_selectmap_conf, core)
  27
  28 static int xilinx_selectmap_write(struct xilinx_fpga_core *core,
  29                                   const char *buf, size_t count)
  30 {
  31         struct xilinx_selectmap_conf *conf = to_xilinx_selectmap_conf(core);
  32         size_t i;
  33
  34         for (i = 0; i < count; ++i)
  35                 writeb(buf[i], conf->base);
  36
  37         return 0;
  38 }
  39
  40 static int xilinx_selectmap_probe(struct platform_device *pdev)
  41 {
  42         struct xilinx_selectmap_conf *conf;
  43         struct gpio_desc *gpio;
  44         void __iomem *base;
  45
  46         conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
  47         if (!conf)
  48                 return -ENOMEM;
  49
  50         conf->core.dev = &pdev->dev;
  51         conf->core.write = xilinx_selectmap_write;
  52
  53         base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
  54         if (IS_ERR(base))
  55                 return dev_err_probe(&pdev->dev, PTR_ERR(base),
  56                                      "ioremap error\n");
  57         conf->base = base;
  58
  59         /* CSI_B is active low */
  60         gpio = devm_gpiod_get_optional(&pdev->dev, "csi", GPIOD_OUT_HIGH);
  61         if (IS_ERR(gpio))
  62                 return dev_err_probe(&pdev->dev, PTR_ERR(gpio),
  63                                      "Failed to get CSI_B gpio\n");
  64
  65         /* RDWR_B is active low */
  66         gpio = devm_gpiod_get_optional(&pdev->dev, "rdwr", GPIOD_OUT_HIGH);
  67         if (IS_ERR(gpio))
  68                 return dev_err_probe(&pdev->dev, PTR_ERR(gpio),
  69                                      "Failed to get RDWR_B gpio\n");
  70
  71         return xilinx_core_probe(&conf->core);
  72 }
  73
  74 static const struct of_device_id xlnx_selectmap_of_match[] = {
  75         { .compatible = "xlnx,fpga-xc7s-selectmap", }, // Spartan-7
  76         { .compatible = "xlnx,fpga-xc7a-selectmap", }, // Artix-7
  77         { .compatible = "xlnx,fpga-xc7k-selectmap", }, // Kintex-7
  78         { .compatible = "xlnx,fpga-xc7v-selectmap", }, // Virtex-7
  79         {},
  80 };
  81 MODULE_DEVICE_TABLE(of, xlnx_selectmap_of_match);
  82
  83 static struct platform_driver xilinx_selectmap_driver = {
  84         .driver = {
  85                 .name = "xilinx-selectmap",
  86                 .of_match_table = xlnx_selectmap_of_match,
  87         },
  88         .probe  = xilinx_selectmap_probe,
  89 };
  90
  91 module_platform_driver(xilinx_selectmap_driver);
  92
  93 MODULE_LICENSE("GPL");
  94 MODULE_AUTHOR("Charles Perry <charles.perry@savoirfairelinux.com>");
  95 MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SelectMap");