drivers/mtd/hyperbus/hbmc-am654.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
   4 // Author: Vignesh Raghavendra <vigneshr@ti.com>
   5
   6 #include <linux/err.h>
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/mtd/cfi.h>
  10 #include <linux/mtd/hyperbus.h>
  11 #include <linux/mtd/mtd.h>
  12 #include <linux/mux/consumer.h>
  13 #include <linux/of.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/types.h>
  17
  18 #define AM654_HBMC_CALIB_COUNT 25
  19
  20 struct am654_hbmc_priv {
  21         struct hyperbus_ctlr ctlr;
  22         struct hyperbus_device hbdev;
  23         struct mux_control *mux_ctrl;
  24 };
  25
  26 static int am654_hbmc_calibrate(struct hyperbus_device *hbdev)
  27 {
  28         struct map_info *map = &hbdev->map;
  29         struct cfi_private cfi;
  30         int count = AM654_HBMC_CALIB_COUNT;
  31         int pass_count = 0;
  32         int ret;
  33
  34         cfi.interleave = 1;
  35         cfi.device_type = CFI_DEVICETYPE_X16;
  36         cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
  37         cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
  38
  39         while (count--) {
  40                 ret = cfi_qry_present(map, 0, &cfi);
  41                 if (ret)
  42                         pass_count++;
  43                 else
  44                         pass_count = 0;
  45                 if (pass_count == 5)
  46                         break;
  47         }
  48
  49         cfi_qry_mode_off(0, map, &cfi);
  50
  51         return ret;
  52 }
  53
  54 static const struct hyperbus_ops am654_hbmc_ops = {
  55         .calibrate = am654_hbmc_calibrate,
  56 };
  57
  58 static int am654_hbmc_probe(struct platform_device *pdev)
  59 {
  60         struct device *dev = &pdev->dev;
  61         struct am654_hbmc_priv *priv;
  62         int ret;
  63
  64         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  65         if (!priv)
  66                 return -ENOMEM;
  67
  68         platform_set_drvdata(pdev, priv);
  69
  70         if (of_property_read_bool(dev->of_node, "mux-controls")) {
  71                 struct mux_control *control = devm_mux_control_get(dev, NULL);
  72
  73                 if (IS_ERR(control))
  74                         return PTR_ERR(control);
  75
  76                 ret = mux_control_select(control, 1);
  77                 if (ret) {
  78                         dev_err(dev, "Failed to select HBMC mux\n");
  79                         return ret;
  80                 }
  81                 priv->mux_ctrl = control;
  82         }
  83
  84         pm_runtime_enable(dev);
  85         ret = pm_runtime_get_sync(dev);
  86         if (ret < 0) {
  87                 pm_runtime_put_noidle(dev);
  88                 goto disable_pm;
  89         }
  90
  91         priv->ctlr.dev = dev;
  92         priv->ctlr.ops = &am654_hbmc_ops;
  93         priv->hbdev.ctlr = &priv->ctlr;
  94         priv->hbdev.np = of_get_next_child(dev->of_node, NULL);
  95         ret = hyperbus_register_device(&priv->hbdev);
  96         if (ret) {
  97                 dev_err(dev, "failed to register controller\n");
  98                 pm_runtime_put_sync(&pdev->dev);
  99                 goto disable_pm;
 100         }
 101
 102         return 0;
 103 disable_pm:
 104         pm_runtime_disable(dev);
 105         if (priv->mux_ctrl)
 106                 mux_control_deselect(priv->mux_ctrl);
 107         return ret;
 108 }
 109
 110 static int am654_hbmc_remove(struct platform_device *pdev)
 111 {
 112         struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
 113         int ret;
 114
 115         ret = hyperbus_unregister_device(&priv->hbdev);
 116         if (priv->mux_ctrl)
 117                 mux_control_deselect(priv->mux_ctrl);
 118         pm_runtime_put_sync(&pdev->dev);
 119         pm_runtime_disable(&pdev->dev);
 120
 121         return ret;
 122 }
 123
 124 static const struct of_device_id am654_hbmc_dt_ids[] = {
 125         {
 126                 .compatible = "ti,am654-hbmc",
 127         },
 128         { /* end of table */ }
 129 };
 130
 131 MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
 132
 133 static struct platform_driver am654_hbmc_platform_driver = {
 134         .probe = am654_hbmc_probe,
 135         .remove = am654_hbmc_remove,
 136         .driver = {
 137                 .name = "hbmc-am654",
 138                 .of_match_table = am654_hbmc_dt_ids,
 139         },
 140 };
 141
 142 module_platform_driver(am654_hbmc_platform_driver);
 143
 144 MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
 145 MODULE_LICENSE("GPL v2");
 146 MODULE_ALIAS("platform:hbmc-am654");
 147 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");