1// SPDX-License-Identifier: ISC
  2/* Initialize Owl Emulation Devices
  3 *
  4 * Copyright (C) 2016 Christian Lamparter <chunkeey@gmail.com>
  5 * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
  6 *
  7 * Some devices (like the Cisco Meraki Z1 Cloud Managed Teleworker Gateway)
  8 * need to be able to initialize the PCIe wifi device. Normally, this is done
  9 * during the early stages as a pci quirk.
 10 * However, this isn't possible for devices which have the init code for the
 11 * Atheros chip stored on UBI Volume on NAND. Hence, this module can be used to
 12 * initialize the chip when the user-space is ready to extract the init code.
 13 */
 14#include <linux/module.h>
 15#include <linux/completion.h>
 16#include <linux/etherdevice.h>
 17#include <linux/firmware.h>
 18#include <linux/pci.h>
 19#include <linux/delay.h>
 20#include <linux/platform_device.h>
 21#include <linux/ath9k_platform.h>
 22
 23struct owl_ctx {
 24	struct completion eeprom_load;
 25};
 26
 27#define EEPROM_FILENAME_LEN 100
 28
 29#define AR5416_EEPROM_MAGIC 0xa55a
 30
 31static int ath9k_pci_fixup(struct pci_dev *pdev, const u16 *cal_data,
 32			   size_t cal_len)
 33{
 34	void __iomem *mem;
 35	const void *cal_end = (void *)cal_data + cal_len;
 36	const struct {
 37		u16 reg;
 38		u16 low_val;
 39		u16 high_val;
 40	} __packed * data;
 41	u16 cmd;
 42	u32 bar0;
 43	bool swap_needed = false;
 44
 45	if (*cal_data != AR5416_EEPROM_MAGIC) {
 46		if (*cal_data != swab16(AR5416_EEPROM_MAGIC)) {
 47			dev_err(&pdev->dev, "invalid calibration data\n");
 48			return -EINVAL;
 49		}
 50
 51		dev_dbg(&pdev->dev, "calibration data needs swapping\n");
 52		swap_needed = true;
 53	}
 54
 55	dev_info(&pdev->dev, "fixup device configuration\n");
 56
 57	mem = pcim_iomap(pdev, 0, 0);
 58	if (!mem) {
 59		dev_err(&pdev->dev, "ioremap error\n");
 60		return -EINVAL;
 61	}
 62
 63	pci_read_config_dword(pdev, PCI_BASE_ADDRESS_0, &bar0);
 64	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0,
 65			       pci_resource_start(pdev, 0));
 66	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 67	cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
 68	pci_write_config_word(pdev, PCI_COMMAND, cmd);
 69
 70	/* set pointer to first reg address */
 71	for (data = (const void *)(cal_data + 3);
 72	     (const void *)data <= cal_end && data->reg != (u16)~0;
 73	     data++) {
 74		u32 val;
 75		u16 reg;
 76
 77		reg = data->reg;
 78		val = data->low_val;
 79		val |= ((u32)data->high_val) << 16;
 80
 81		if (swap_needed) {
 82			reg = swab16(reg);
 83			val = swahb32(val);
 84		}
 85
 86		iowrite32(val, mem + reg);
 87		usleep_range(100, 120);
 88	}
 89
 90	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 91	cmd &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
 92	pci_write_config_word(pdev, PCI_COMMAND, cmd);
 93
 94	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, bar0);
 95	pcim_iounmap(pdev, mem);
 96
 97	pci_disable_device(pdev);
 98
 99	return 0;
100}
101
102static void owl_fw_cb(const struct firmware *fw, void *context)
103{
104	struct pci_dev *pdev = (struct pci_dev *)context;
105	struct owl_ctx *ctx = (struct owl_ctx *)pci_get_drvdata(pdev);
106	struct pci_bus *bus;
107
108	complete(&ctx->eeprom_load);
109
110	if (!fw) {
111		dev_err(&pdev->dev, "no eeprom data received.\n");
112		goto release;
113	}
114
115	/* also note that we are doing *u16 operations on the file */
116	if (fw->size > 4096 || fw->size < 0x200 || (fw->size & 1) == 1) {
117		dev_err(&pdev->dev, "eeprom file has an invalid size.\n");
118		goto release;
119	}
120
121	if (ath9k_pci_fixup(pdev, (const u16 *)fw->data, fw->size))
122		goto release;
123
124	pci_lock_rescan_remove();
125	bus = pdev->bus;
126	pci_stop_and_remove_bus_device(pdev);
127	/* the device should come back with the proper
128	 * ProductId. But we have to initiate a rescan.
129	 */
130	pci_rescan_bus(bus);
131	pci_unlock_rescan_remove();
132
133release:
134	release_firmware(fw);
135}
136
137static const char *owl_get_eeprom_name(struct pci_dev *pdev)
138{
139	struct device *dev = &pdev->dev;
140	char *eeprom_name;
141
142	dev_dbg(dev, "using auto-generated eeprom filename\n");
143
144	eeprom_name = devm_kzalloc(dev, EEPROM_FILENAME_LEN, GFP_KERNEL);
145	if (!eeprom_name)
146		return NULL;
147
148	/* this should match the pattern used in ath9k/init.c */
149	scnprintf(eeprom_name, EEPROM_FILENAME_LEN, "ath9k-eeprom-pci-%s.bin",
150		  dev_name(dev));
151
152	return eeprom_name;
153}
154
155static int owl_probe(struct pci_dev *pdev,
156		     const struct pci_device_id *id)
157{
158	struct owl_ctx *ctx;
159	const char *eeprom_name;
160	int err = 0;
161
162	if (pcim_enable_device(pdev))
163		return -EIO;
164
165	pcim_pin_device(pdev);
166
167	eeprom_name = owl_get_eeprom_name(pdev);
168	if (!eeprom_name) {
169		dev_err(&pdev->dev, "no eeprom filename found.\n");
170		return -ENODEV;
171	}
172
173	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
174	if (!ctx)
175		return -ENOMEM;
176
177	init_completion(&ctx->eeprom_load);
178
179	pci_set_drvdata(pdev, ctx);
180	err = request_firmware_nowait(THIS_MODULE, true, eeprom_name,
181				      &pdev->dev, GFP_KERNEL, pdev, owl_fw_cb);
182	if (err)
183		dev_err(&pdev->dev, "failed to request caldata (%d).\n", err);
184
185	return err;
186}
187
188static void owl_remove(struct pci_dev *pdev)
189{
190	struct owl_ctx *ctx = pci_get_drvdata(pdev);
191
192	if (ctx) {
193		wait_for_completion(&ctx->eeprom_load);
194		pci_set_drvdata(pdev, NULL);
195	}
196}
197
198static const struct pci_device_id owl_pci_table[] = {
199	{ PCI_VDEVICE(ATHEROS, 0xff1c) }, /* PCIe */
200	{ PCI_VDEVICE(ATHEROS, 0xff1d) }, /* PCI */
201	{ },
202};
203MODULE_DEVICE_TABLE(pci, owl_pci_table);
204
205static struct pci_driver owl_driver = {
206	.name		= KBUILD_MODNAME,
207	.id_table	= owl_pci_table,
208	.probe		= owl_probe,
209	.remove		= owl_remove,
210};
211module_pci_driver(owl_driver);
212MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
213MODULE_DESCRIPTION("External EEPROM data loader for Atheros AR500X to AR92XX");
214MODULE_LICENSE("Dual BSD/GPL");