text: // SPDX-License-Identifier: GPL-2.0+
  //
  // Copyright 2012 Freescale Semiconductor, Inc.
  // Copyright 2012 Linaro Ltd.
  // Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
  //
  // Initial development of this code was funded by
  // Phytec Messtechnik GmbH, http://www.phytec.de
  
  #include <linux/clk.h>
  #include <linux/debugfs.h>
  #include <linux/err.h>
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  
  #include "imx-audmux.h"
  
  #define DRIVER_NAME "imx-audmux"
  
  static struct clk *audmux_clk;
  static void __iomem *audmux_base;
  
  #define IMX_AUDMUX_V2_PTCR(x)		((x) * 8)
  #define IMX_AUDMUX_V2_PDCR(x)		((x) * 8 + 4)
  
  #ifdef CONFIG_DEBUG_FS
  static struct dentry *audmux_debugfs_root;
  
  /* There is an annoying discontinuity in the SSI numbering with regard
   * to the Linux number of the devices */
  static const char *audmux_port_string(int port)
  {
  	switch (port) {
  	case MX31_AUDMUX_PORT1_SSI0:
  		return "imx-ssi.0";
  	case MX31_AUDMUX_PORT2_SSI1:
  		return "imx-ssi.1";
  	case MX31_AUDMUX_PORT3_SSI_PINS_3:
  		return "SSI3";
  	case MX31_AUDMUX_PORT4_SSI_PINS_4:
  		return "SSI4";
  	case MX31_AUDMUX_PORT5_SSI_PINS_5:
  		return "SSI5";
  	case MX31_AUDMUX_PORT6_SSI_PINS_6:
  		return "SSI6";
  	default:
  		return "UNKNOWN";
  	}
  }
  
  static ssize_t audmux_read_file(struct file *file, char __user *user_buf,
  				size_t count, loff_t *ppos)
  {
  	ssize_t ret;
  	char *buf;
  	uintptr_t port = (uintptr_t)file->private_data;
  	u32 pdcr, ptcr;
  
  	if (audmux_clk) {
  		ret = clk_prepare_enable(audmux_clk);
  		if (ret)
  			return ret;
  	}
  
  	ptcr = readl(audmux_base + IMX_AUDMUX_V2_PTCR(port));
  	pdcr = readl(audmux_base + IMX_AUDMUX_V2_PDCR(port));
  
  	if (audmux_clk)
  		clk_disable_unprepare(audmux_clk);
  
  	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
  	if (!buf)
  		return -ENOMEM;
  
  	ret = scnprintf(buf, PAGE_SIZE, "PDCR: %08x\nPTCR: %08x\n",
  		       pdcr, ptcr);
  
  	if (ptcr & IMX_AUDMUX_V2_PTCR_TFSDIR)
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  				"TxFS output from %s, ",
  				audmux_port_string((ptcr >> 27) & 0x7));
  	else
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  				"TxFS input, ");
  
  	if (ptcr & IMX_AUDMUX_V2_PTCR_TCLKDIR)
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  				"TxClk output from %s",
  				audmux_port_string((ptcr >> 22) & 0x7));
  	else
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  				"TxClk input");
  
  	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
  
  	if (ptcr & IMX_AUDMUX_V2_PTCR_SYN) {
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  				"Port is symmetric");
  	} else {
  		if (ptcr & IMX_AUDMUX_V2_PTCR_RFSDIR)
  			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  					"RxFS output from %s, ",
  					audmux_port_string((ptcr >> 17) & 0x7));
  		else
  			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  					"RxFS input, ");
  
  		if (ptcr & IMX_AUDMUX_V2_PTCR_RCLKDIR)
  			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  					"RxClk output from %s",
  					audmux_port_string((ptcr >> 12) & 0x7));
  		else
  			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  					"RxClk input");
  	}
  
  	ret += scnprintf(buf + ret, PAGE_SIZE - ret,
  			"\nData received from %s\n",
  			audmux_port_string((pdcr >> 13) & 0x7));
  
  	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
  
  	kfree(buf);
  
  	return ret;
  }
  
  static const struct file_operations audmux_debugfs_fops = {
  	.open = simple_open,
  	.read = audmux_read_file,
  	.llseek = default_llseek,
  };
  
  static void audmux_debugfs_init(void)
  {
  	uintptr_t i;
  	char buf[20];
  
  	audmux_debugfs_root = debugfs_create_dir("audmux", NULL);
  
  	for (i = 0; i < MX31_AUDMUX_PORT7_SSI_PINS_7 + 1; i++) {
  		snprintf(buf, sizeof(buf), "ssi%lu", i);
  		debugfs_create_file(buf, 0444, audmux_debugfs_root,
  				    (void *)i, &audmux_debugfs_fops);
  	}
  }
  
  static void audmux_debugfs_remove(void)
  {
  	debugfs_remove_recursive(audmux_debugfs_root);
  }
  #else
  static inline void audmux_debugfs_init(void)
  {
  }
  
  static inline void audmux_debugfs_remove(void)
  {
  }
  #endif
  
  static enum imx_audmux_type {
  	IMX21_AUDMUX,
  	IMX31_AUDMUX,
  } audmux_type;
  
  static const struct platform_device_id imx_audmux_ids[] = {
  	{
  		.name = "imx21-audmux",
  		.driver_data = IMX21_AUDMUX,
  	}, {
  		.name = "imx31-audmux",
  		.driver_data = IMX31_AUDMUX,
  	}, {
  		/* sentinel */
  	}
  };
  MODULE_DEVICE_TABLE(platform, imx_audmux_ids);
  
  static const struct of_device_id imx_audmux_dt_ids[] = {
  	{ .compatible = "fsl,imx21-audmux", .data = &imx_audmux_ids[0], },
  	{ .compatible = "fsl,imx31-audmux", .data = &imx_audmux_ids[1], },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, imx_audmux_dt_ids);
  
  static const uint8_t port_mapping[] = {
  	0x0, 0x4, 0x8, 0x10, 0x14, 0x1c,
  };
  
  int imx_audmux_v1_configure_port(unsigned int port, unsigned int pcr)
  {
  	if (audmux_type != IMX21_AUDMUX)
  		return -EINVAL;
  
  	if (!audmux_base)
  		return -ENOSYS;
  
  	if (port >= ARRAY_SIZE(port_mapping))
  		return -EINVAL;
  
  	writel(pcr, audmux_base + port_mapping[port]);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(imx_audmux_v1_configure_port);
  
  int imx_audmux_v2_configure_port(unsigned int port, unsigned int ptcr,
  		unsigned int pdcr)
  {
  	int ret;
  
  	if (audmux_type != IMX31_AUDMUX)
  		return -EINVAL;
  
  	if (!audmux_base)
  		return -ENOSYS;
  
  	if (audmux_clk) {
  		ret = clk_prepare_enable(audmux_clk);
  		if (ret)
  			return ret;
  	}
  
  	writel(ptcr, audmux_base + IMX_AUDMUX_V2_PTCR(port));
  	writel(pdcr, audmux_base + IMX_AUDMUX_V2_PDCR(port));
  
  	if (audmux_clk)
  		clk_disable_unprepare(audmux_clk);
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(imx_audmux_v2_configure_port);
  
  static int imx_audmux_parse_dt_defaults(struct platform_device *pdev,
  		struct device_node *of_node)
  {
  	struct device_node *child;
  
  	for_each_available_child_of_node(of_node, child) {
  		unsigned int port;
  		unsigned int ptcr = 0;
  		unsigned int pdcr = 0;
  		unsigned int pcr = 0;
  		unsigned int val;
  		int ret;
  		int i = 0;
  
  		ret = of_property_read_u32(child, "fsl,audmux-port", &port);
  		if (ret) {
  			dev_warn(&pdev->dev, "Failed to get fsl,audmux-port of child node \"%pOF\"\n",
  					child);
  			continue;
  		}
  		if (!of_property_read_bool(child, "fsl,port-config")) {
  			dev_warn(&pdev->dev, "child node \"%pOF\" does not have property fsl,port-config\n",
  					child);
  			continue;
  		}
  
  		for (i = 0; (ret = of_property_read_u32_index(child,
  					"fsl,port-config", i, &val)) == 0;
  				++i) {
  			if (audmux_type == IMX31_AUDMUX) {
  				if (i % 2)
  					pdcr |= val;
  				else
  					ptcr |= val;
  			} else {
  				pcr |= val;
  			}
  		}
  
  		if (ret != -EOVERFLOW) {
  			dev_err(&pdev->dev, "Failed to read u32 at index %d of child %pOF\n",
  					i, child);
  			continue;
  		}
  
  		if (audmux_type == IMX31_AUDMUX) {
  			if (i % 2) {
  				dev_err(&pdev->dev, "One pdcr value is missing in child node %pOF\n",
  						child);
  				continue;
  			}
  			imx_audmux_v2_configure_port(port, ptcr, pdcr);
  		} else {
  			imx_audmux_v1_configure_port(port, pcr);
  		}
  	}
  
  	return 0;
  }
  
  static int imx_audmux_probe(struct platform_device *pdev)
  {
  	struct resource *res;
  	const struct of_device_id *of_id =
  			of_match_device(imx_audmux_dt_ids, &pdev->dev);
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	audmux_base = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(audmux_base))
  		return PTR_ERR(audmux_base);
  
  	audmux_clk = devm_clk_get(&pdev->dev, "audmux");
  	if (IS_ERR(audmux_clk)) {
  		dev_dbg(&pdev->dev, "cannot get clock: %ld\n",
  				PTR_ERR(audmux_clk));
  		audmux_clk = NULL;
  	}
  
  	if (of_id)
  		pdev->id_entry = of_id->data;
  	audmux_type = pdev->id_entry->driver_data;
  	if (audmux_type == IMX31_AUDMUX)
  		audmux_debugfs_init();
  
  	if (of_id)
  		imx_audmux_parse_dt_defaults(pdev, pdev->dev.of_node);
  
  	return 0;
  }
  
  static int imx_audmux_remove(struct platform_device *pdev)
  {
  	if (audmux_type == IMX31_AUDMUX)
  		audmux_debugfs_remove();
  
  	return 0;
  }
  
  static struct platform_driver imx_audmux_driver = {
  	.probe		= imx_audmux_probe,
  	.remove		= imx_audmux_remove,
  	.id_table	= imx_audmux_ids,
  	.driver	= {
  		.name	= DRIVER_NAME,
  		.of_match_table = imx_audmux_dt_ids,
  	}
  };
  
  static int __init imx_audmux_init(void)
  {
  	return platform_driver_register(&imx_audmux_driver);
  }
  subsys_initcall(imx_audmux_init);
  
  static void __exit imx_audmux_exit(void)
  {
  	platform_driver_unregister(&imx_audmux_driver);
  }
  module_exit(imx_audmux_exit);
  
  MODULE_DESCRIPTION("Freescale i.MX AUDMUX driver");
  MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:" DRIVER_NAME);
  