1/*
  2 * QorIQ 10G MDIO Controller
  3 *
  4 * Copyright 2012 Freescale Semiconductor, Inc.
  5 *
  6 * Authors: Andy Fleming <afleming@freescale.com>
  7 *          Timur Tabi <timur@freescale.com>
  8 *
  9 * This file is licensed under the terms of the GNU General Public License
 10 * version 2.  This program is licensed "as is" without any warranty of any
 11 * kind, whether express or implied.
 12 */
 13
 14#include <linux/kernel.h>
 15#include <linux/slab.h>
 16#include <linux/interrupt.h>
 17#include <linux/module.h>
 18#include <linux/phy.h>
 19#include <linux/mdio.h>
 20#include <linux/of_address.h>
 21#include <linux/of_platform.h>
 22#include <linux/of_mdio.h>
 23
 24/* Number of microseconds to wait for a register to respond */
 25#define TIMEOUT	1000
 26
 27struct tgec_mdio_controller {
 28	__be32	reserved[12];
 29	__be32	mdio_stat;	/* MDIO configuration and status */
 30	__be32	mdio_ctl;	/* MDIO control */
 31	__be32	mdio_data;	/* MDIO data */
 32	__be32	mdio_addr;	/* MDIO address */
 33} __packed;
 34
 35#define MDIO_STAT_ENC		BIT(6)
 36#define MDIO_STAT_CLKDIV(x)	(((x>>1) & 0xff) << 8)
 37#define MDIO_STAT_BSY		BIT(0)
 38#define MDIO_STAT_RD_ER		BIT(1)
 39#define MDIO_CTL_DEV_ADDR(x) 	(x & 0x1f)
 40#define MDIO_CTL_PORT_ADDR(x)	((x & 0x1f) << 5)
 41#define MDIO_CTL_PRE_DIS	BIT(10)
 42#define MDIO_CTL_SCAN_EN	BIT(11)
 43#define MDIO_CTL_POST_INC	BIT(14)
 44#define MDIO_CTL_READ		BIT(15)
 45
 46#define MDIO_DATA(x)		(x & 0xffff)
 47#define MDIO_DATA_BSY		BIT(31)
 48
 49struct mdio_fsl_priv {
 50	struct	tgec_mdio_controller __iomem *mdio_base;
 51	bool	is_little_endian;
 52	bool	has_a011043;
 53};
 54
 55static u32 xgmac_read32(void __iomem *regs,
 56			bool is_little_endian)
 57{
 58	if (is_little_endian)
 59		return ioread32(regs);
 60	else
 61		return ioread32be(regs);
 62}
 63
 64static void xgmac_write32(u32 value,
 65			  void __iomem *regs,
 66			  bool is_little_endian)
 67{
 68	if (is_little_endian)
 69		iowrite32(value, regs);
 70	else
 71		iowrite32be(value, regs);
 72}
 73
 74/*
 75 * Wait until the MDIO bus is free
 76 */
 77static int xgmac_wait_until_free(struct device *dev,
 78				 struct tgec_mdio_controller __iomem *regs,
 79				 bool is_little_endian)
 80{
 81	unsigned int timeout;
 82
 83	/* Wait till the bus is free */
 84	timeout = TIMEOUT;
 85	while ((xgmac_read32(&regs->mdio_stat, is_little_endian) &
 86		MDIO_STAT_BSY) && timeout) {
 87		cpu_relax();
 88		timeout--;
 89	}
 90
 91	if (!timeout) {
 92		dev_err(dev, "timeout waiting for bus to be free\n");
 93		return -ETIMEDOUT;
 94	}
 95
 96	return 0;
 97}
 98
 99/*
100 * Wait till the MDIO read or write operation is complete
101 */
102static int xgmac_wait_until_done(struct device *dev,
103				 struct tgec_mdio_controller __iomem *regs,
104				 bool is_little_endian)
105{
106	unsigned int timeout;
107
108	/* Wait till the MDIO write is complete */
109	timeout = TIMEOUT;
110	while ((xgmac_read32(&regs->mdio_stat, is_little_endian) &
111		MDIO_STAT_BSY) && timeout) {
112		cpu_relax();
113		timeout--;
114	}
115
116	if (!timeout) {
117		dev_err(dev, "timeout waiting for operation to complete\n");
118		return -ETIMEDOUT;
119	}
120
121	return 0;
122}
123
124/*
125 * Write value to the PHY for this device to the register at regnum,waiting
126 * until the write is done before it returns.  All PHY configuration has to be
127 * done through the TSEC1 MIIM regs.
128 */
129static int xgmac_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
130{
131	struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
132	struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
133	uint16_t dev_addr;
134	u32 mdio_ctl, mdio_stat;
135	int ret;
136	bool endian = priv->is_little_endian;
137
138	mdio_stat = xgmac_read32(&regs->mdio_stat, endian);
139	if (regnum & MII_ADDR_C45) {
140		/* Clause 45 (ie 10G) */
141		dev_addr = (regnum >> 16) & 0x1f;
142		mdio_stat |= MDIO_STAT_ENC;
143	} else {
144		/* Clause 22 (ie 1G) */
145		dev_addr = regnum & 0x1f;
146		mdio_stat &= ~MDIO_STAT_ENC;
147	}
148
149	xgmac_write32(mdio_stat, &regs->mdio_stat, endian);
150
151	ret = xgmac_wait_until_free(&bus->dev, regs, endian);
152	if (ret)
153		return ret;
154
155	/* Set the port and dev addr */
156	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
157	xgmac_write32(mdio_ctl, &regs->mdio_ctl, endian);
158
159	/* Set the register address */
160	if (regnum & MII_ADDR_C45) {
161		xgmac_write32(regnum & 0xffff, &regs->mdio_addr, endian);
162
163		ret = xgmac_wait_until_free(&bus->dev, regs, endian);
164		if (ret)
165			return ret;
166	}
167
168	/* Write the value to the register */
169	xgmac_write32(MDIO_DATA(value), &regs->mdio_data, endian);
170
171	ret = xgmac_wait_until_done(&bus->dev, regs, endian);
172	if (ret)
173		return ret;
174
175	return 0;
176}
177
178/*
179 * Reads from register regnum in the PHY for device dev, returning the value.
180 * Clears miimcom first.  All PHY configuration has to be done through the
181 * TSEC1 MIIM regs.
182 */
183static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
184{
185	struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
186	struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
187	uint16_t dev_addr;
188	uint32_t mdio_stat;
189	uint32_t mdio_ctl;
190	uint16_t value;
191	int ret;
192	bool endian = priv->is_little_endian;
193
194	mdio_stat = xgmac_read32(&regs->mdio_stat, endian);
195	if (regnum & MII_ADDR_C45) {
196		dev_addr = (regnum >> 16) & 0x1f;
197		mdio_stat |= MDIO_STAT_ENC;
198	} else {
199		dev_addr = regnum & 0x1f;
200		mdio_stat &= ~MDIO_STAT_ENC;
201	}
202
203	xgmac_write32(mdio_stat, &regs->mdio_stat, endian);
204
205	ret = xgmac_wait_until_free(&bus->dev, regs, endian);
206	if (ret)
207		return ret;
208
209	/* Set the Port and Device Addrs */
210	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
211	xgmac_write32(mdio_ctl, &regs->mdio_ctl, endian);
212
213	/* Set the register address */
214	if (regnum & MII_ADDR_C45) {
215		xgmac_write32(regnum & 0xffff, &regs->mdio_addr, endian);
216
217		ret = xgmac_wait_until_free(&bus->dev, regs, endian);
218		if (ret)
219			return ret;
220	}
221
222	/* Initiate the read */
223	xgmac_write32(mdio_ctl | MDIO_CTL_READ, &regs->mdio_ctl, endian);
224
225	ret = xgmac_wait_until_done(&bus->dev, regs, endian);
226	if (ret)
227		return ret;
228
229	/* Return all Fs if nothing was there */
230	if ((xgmac_read32(&regs->mdio_stat, endian) & MDIO_STAT_RD_ER) &&
231	    !priv->has_a011043) {
232		dev_dbg(&bus->dev,
233			"Error while reading PHY%d reg at %d.%hhu\n",
234			phy_id, dev_addr, regnum);
235		return 0xffff;
236	}
237
238	value = xgmac_read32(&regs->mdio_data, endian) & 0xffff;
239	dev_dbg(&bus->dev, "read %04x\n", value);
240
241	return value;
242}
243
244static int xgmac_mdio_probe(struct platform_device *pdev)
245{
246	struct device_node *np = pdev->dev.of_node;
247	struct mii_bus *bus;
248	struct resource *res;
249	struct mdio_fsl_priv *priv;
250	int ret;
251
252	/* In DPAA-1, MDIO is one of the many FMan sub-devices. The FMan
253	 * defines a register space that spans a large area, covering all the
254	 * subdevice areas. Therefore, MDIO cannot claim exclusive access to
255	 * this register area.
256	 */
257	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
258	if (!res) {
259		dev_err(&pdev->dev, "could not obtain address\n");
260		return -EINVAL;
261	}
262
263	bus = mdiobus_alloc_size(sizeof(struct mdio_fsl_priv));
264	if (!bus)
265		return -ENOMEM;
266
267	bus->name = "Freescale XGMAC MDIO Bus";
268	bus->read = xgmac_mdio_read;
269	bus->write = xgmac_mdio_write;
270	bus->parent = &pdev->dev;
271	bus->probe_capabilities = MDIOBUS_C22_C45;
272	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res->start);
273
274	/* Set the PHY base address */
275	priv = bus->priv;
276	priv->mdio_base = ioremap(res->start, resource_size(res));
277	if (!priv->mdio_base) {
278		ret = -ENOMEM;
279		goto err_ioremap;
280	}
281
282	priv->is_little_endian = device_property_read_bool(&pdev->dev,
283							   "little-endian");
284
285	priv->has_a011043 = device_property_read_bool(&pdev->dev,
286						      "fsl,erratum-a011043");
287
288	ret = of_mdiobus_register(bus, np);
289	if (ret) {
290		dev_err(&pdev->dev, "cannot register MDIO bus\n");
291		goto err_registration;
292	}
293
294	platform_set_drvdata(pdev, bus);
295
296	return 0;
297
298err_registration:
299	iounmap(priv->mdio_base);
300
301err_ioremap:
302	mdiobus_free(bus);
303
304	return ret;
305}
306
307static int xgmac_mdio_remove(struct platform_device *pdev)
308{
309	struct mii_bus *bus = platform_get_drvdata(pdev);
310
311	mdiobus_unregister(bus);
312	iounmap(bus->priv);
313	mdiobus_free(bus);
314
315	return 0;
316}
317
318static const struct of_device_id xgmac_mdio_match[] = {
319	{
320		.compatible = "fsl,fman-xmdio",
321	},
322	{
323		.compatible = "fsl,fman-memac-mdio",
324	},
325	{},
326};
327MODULE_DEVICE_TABLE(of, xgmac_mdio_match);
328
329static const struct acpi_device_id xgmac_acpi_match[] = {
330	{ "NXP0006" },
331	{ }
332};
333MODULE_DEVICE_TABLE(acpi, xgmac_acpi_match);
334
335static struct platform_driver xgmac_mdio_driver = {
336	.driver = {
337		.name = "fsl-fman_xmdio",
338		.of_match_table = xgmac_mdio_match,
339		.acpi_match_table = xgmac_acpi_match,
340	},
341	.probe = xgmac_mdio_probe,
342	.remove = xgmac_mdio_remove,
343};
344
345module_platform_driver(xgmac_mdio_driver);
346
347MODULE_DESCRIPTION("Freescale QorIQ 10G MDIO Controller");
348MODULE_LICENSE("GPL v2");