i2400m/SDIO: probe/disconnect, dev init/shutdown and reset backends

Implements probe/disconnect for the SDIO device, as well as main
backends for the generic driver to control the SDIO device
(bus_dev_start(), bus_dev_stop() and bus_reset()).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/wimax/i2400m/sdio.c

+/*
+ * Intel Wireless WiMAX Connection 2400m
+ * Linux driver model glue for the SDIO device, reset & fw upload
+ *
+ *
+ * Copyright (C) 2007-2008 Intel Corporation <linux-wimax@intel.com>
+ * Dirk Brandewie <dirk.j.brandewie@intel.com>
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Yanir Lubetkin <yanirx.lubetkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * See i2400m-sdio.h for a general description of this driver.
+ *
+ * This file implements driver model glue, and hook ups for the
+ * generic driver to implement the bus-specific functions (device
+ * communication setup/tear down, firmware upload and resetting).
+ *
+ * ROADMAP
+ *
+ * i2400m_probe()
+ *   alloc_netdev()
+ *     i2400ms_netdev_setup()
+ *       i2400ms_init()
+ *       i2400m_netdev_setup()
+ *   i2400ms_enable_function()
+ *   i2400m_setup()
+ *
+ * i2400m_remove()
+ *     i2400m_release()
+ *     free_netdev(net_dev)
+ *
+ * i2400ms_bus_reset()            Called by i2400m->bus_reset
+ *   __i2400ms_reset()
+ *     __i2400ms_send_barker()
+ *
+ * i2400ms_bus_dev_start()        Called by i2400m_dev_start() [who is
+ *   i2400ms_tx_setup()           called by i2400m_setup()]
+ *   i2400ms_rx_setup()
+ *
+ * i2400ms_bus_dev_stop()         Called by i2400m_dev_stop() [who is
+ *   i2400ms_rx_release()         is called by i2400m_release()]
+ *   i2400ms_tx_release()
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/sdio_func.h>
+#include "i2400m-sdio.h"
+#include <linux/wimax/i2400m.h>
+
+#define D_SUBMODULE main
+#include "sdio-debug-levels.h"
+
+/* IOE WiMAX function timeout in seconds */
+static int ioe_timeout = 2;
+module_param(ioe_timeout, int, 0);
+
+/* Our firmware file name */
+#define I2400MS_FW_FILE_NAME "i2400m-fw-sdio-" I2400M_FW_VERSION ".sbcf"
+
+/*
+ * Enable the SDIO function
+ *
+ * Tries to enable the SDIO function; might fail if it is still not
+ * ready (in some hardware, the SDIO WiMAX function is only enabled
+ * when we ask it to explicitly doing). Tries until a timeout is
+ * reached.
+ *
+ * The reverse of this is...sdio_disable_function()
+ *
+ * Returns: 0 if the SDIO function was enabled, < 0 errno code on
+ *     error (-ENODEV when it was unable to enable the function).
+ */
+static
+int i2400ms_enable_function(struct sdio_func *func)
+{
+	u64 timeout;
+	int err;
+	struct device *dev = &func->dev;
+
+	d_fnstart(3, dev, "(func %p)\n", func);
+	/* Setup timeout (FIXME: This needs to read the CIS table to
+	 * get a real timeout) and then wait for the device to signal
+	 * it is ready */
+	timeout = get_jiffies_64() + ioe_timeout * HZ;
+	err = -ENODEV;
+	while (err != 0 && time_before64(get_jiffies_64(), timeout)) {
+		sdio_claim_host(func);
+		err = sdio_enable_func(func);
+		if (0 == err) {
+			sdio_release_host(func);
+			d_printf(2, dev, "SDIO function enabled\n");
+			goto function_enabled;
+		}
+		d_printf(2, dev, "SDIO function failed to enable: %d\n", err);
+		sdio_disable_func(func);
+		sdio_release_host(func);
+		msleep(I2400MS_INIT_SLEEP_INTERVAL);
+	}
+	/* If timed out, device is not there yet -- get -ENODEV so
+	 * the device driver core will retry later on. */
+	if (err == -ETIME) {
+		dev_err(dev, "Can't enable WiMAX function; "
+			" has the function been enabled?\n");
+		err = -ENODEV;
+	}
+function_enabled:
+	d_fnend(3, dev, "(func %p) = %d\n", func, err);
+	return err;
+}
+
+
+/*
+ * Setup driver resources needed to communicate with the device
+ *
+ * The fw needs some time to settle, and it was just uploaded,
+ * so give it a break first. I'd prefer to just wait for the device to
+ * send something, but seems the poking we do to enable SDIO stuff
+ * interferes with it, so just give it a break before starting...
+ */
+static
+int i2400ms_bus_dev_start(struct i2400m *i2400m)
+{
+	int result;
+	struct i2400ms *i2400ms = container_of(i2400m, struct i2400ms, i2400m);
+	struct sdio_func *func = i2400ms->func;
+	struct device *dev = &func->dev;
+
+	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+	msleep(200);
+	result = i2400ms_rx_setup(i2400ms);
+	if (result < 0)
+		goto error_rx_setup;
+	result = i2400ms_tx_setup(i2400ms);
+	if (result < 0)
+		goto error_tx_setup;
+	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);
+	return result;
+
+	i2400ms_tx_release(i2400ms);
+error_tx_setup:
+	i2400ms_rx_release(i2400ms);
+error_rx_setup:
+	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+	return result;
+}
+
+
+static
+void i2400ms_bus_dev_stop(struct i2400m *i2400m)
+{
+	struct i2400ms *i2400ms = container_of(i2400m, struct i2400ms, i2400m);
+	struct sdio_func *func = i2400ms->func;
+	struct device *dev = &func->dev;
+
+	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);
+	i2400ms_rx_release(i2400ms);
+	i2400ms_tx_release(i2400ms);
+	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
+}
+
+
+/*
+ * Sends a barker buffer to the device
+ *
+ * This helper will allocate a kmalloced buffer and use it to transmit
+ * (then free it). Reason for this is that the SDIO host controller
+ * expects alignment (unknown exactly which) which the stack won't
+ * really provide and certain arches/host-controller combinations
+ * cannot use stack/vmalloc/text areas for DMA transfers.
+ */
+static
+int __i2400ms_send_barker(struct i2400ms *i2400ms,
+			  const __le32 *barker, size_t barker_size)
+{
+	int  ret;
+	struct sdio_func *func = i2400ms->func;
+	struct device *dev = &func->dev;
+	void *buffer;
+
+	ret = -ENOMEM;
+	buffer = kmalloc(I2400MS_BLK_SIZE, GFP_KERNEL);
+	if (buffer == NULL)
+		goto error_kzalloc;
+
+	memcpy(buffer, barker, barker_size);
+	sdio_claim_host(func);
+	ret = sdio_memcpy_toio(func, 0, buffer, I2400MS_BLK_SIZE);
+	sdio_release_host(func);
+
+	if (ret < 0)
+		d_printf(0, dev, "E: barker error: %d\n", ret);
+
+	kfree(buffer);
+error_kzalloc:
+	return ret;
+}
+
+
+/*
+ * Reset a device at different levels (warm, cold or bus)
+ *
+ * @i2400ms: device descriptor
+ * @reset_type: soft, warm or bus reset (I2400M_RT_WARM/SOFT/BUS)
+ *
+ * FIXME: not tested -- need to confirm expected effects
+ *
+ * Warm and cold resets get an SDIO reset if they fail (unimplemented)
+ *
+ * Warm reset:
+ *
+ * The device will be fully reset internally, but won't be
+ * disconnected from the USB bus (so no reenumeration will
+ * happen). Firmware upload will be neccessary.
+ *
+ * The device will send a reboot barker in the notification endpoint
+ * that will trigger the driver to reinitialize the state
+ * automatically from notif.c:i2400m_notification_grok() into
+ * i2400m_dev_bootstrap_delayed().
+ *
+ * Cold and bus (USB) reset:
+ *
+ * The device will be fully reset internally, disconnected from the
+ * USB bus an a reenumeration will happen. Firmware upload will be
+ * neccessary. Thus, we don't do any locking or struct
+ * reinitialization, as we are going to be fully disconnected and
+ * reenumerated.
+ *
+ * Note we need to return -ENODEV if a warm reset was requested and we
+ * had to resort to a bus reset. See i2400m_op_reset(), wimax_reset()
+ * and wimax_dev->op_reset.
+ *
+ * WARNING: no driver state saved/fixed
+ */
+static
+int i2400ms_bus_reset(struct i2400m *i2400m, enum i2400m_reset_type rt)
+{
+	int result;
+	struct i2400ms *i2400ms =
+		container_of(i2400m, struct i2400ms, i2400m);
+	struct device *dev = i2400m_dev(i2400m);
+	static const __le32 i2400m_WARM_BOOT_BARKER[4] = {
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_WARM_RESET_BARKER),
+	};
+	static const __le32 i2400m_COLD_BOOT_BARKER[4] = {
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+		__constant_cpu_to_le32(I2400M_COLD_RESET_BARKER),
+	};
+
+	if (rt == I2400M_RT_WARM)
+		result = __i2400ms_send_barker(i2400ms, i2400m_WARM_BOOT_BARKER,
+					       sizeof(i2400m_WARM_BOOT_BARKER));
+	else if (rt == I2400M_RT_COLD)
+		result = __i2400ms_send_barker(i2400ms, i2400m_COLD_BOOT_BARKER,
+					       sizeof(i2400m_COLD_BOOT_BARKER));
+	else if (rt == I2400M_RT_BUS) {
+do_bus_reset:
+		dev_err(dev, "FIXME: SDIO bus reset not implemented\n");
+		result = rt == I2400M_RT_WARM ? -ENODEV : -ENOSYS;
+	} else
+		BUG();
+	if (result < 0 && rt != I2400M_RT_BUS) {
+		dev_err(dev, "%s reset failed (%d); trying SDIO reset\n",
+			rt == I2400M_RT_WARM ? "warm" : "cold", result);
+		rt = I2400M_RT_BUS;
+		goto do_bus_reset;
+	}
+	return result;
+}
+
+
+static
+void i2400ms_netdev_setup(struct net_device *net_dev)
+{
+	struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
+	struct i2400ms *i2400ms = container_of(i2400m, struct i2400ms, i2400m);
+	i2400ms_init(i2400ms);
+	i2400m_netdev_setup(net_dev);
+}
+
+
+/*
+ * Debug levels control; see debug.h
+ */
+struct d_level D_LEVEL[] = {
+	D_SUBMODULE_DEFINE(main),
+	D_SUBMODULE_DEFINE(tx),
+	D_SUBMODULE_DEFINE(rx),
+	D_SUBMODULE_DEFINE(fw),
+};
+size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
+
+
+#define __debugfs_register(prefix, name, parent)			\
+do {									\
+	result = d_level_register_debugfs(prefix, name, parent);	\
+	if (result < 0)							\
+		goto error;						\
+} while (0)
+
+
+static
+int i2400ms_debugfs_add(struct i2400ms *i2400ms)
+{
+	int result;
+	struct dentry *dentry = i2400ms->i2400m.wimax_dev.debugfs_dentry;
+
+	dentry = debugfs_create_dir("i2400m-usb", dentry);
+	result = PTR_ERR(dentry);
+	if (IS_ERR(dentry)) {
+		if (result == -ENODEV)
+			result = 0;	/* No debugfs support */
+		goto error;
+	}
+	i2400ms->debugfs_dentry = dentry;
+	__debugfs_register("dl_", main, dentry);
+	__debugfs_register("dl_", tx, dentry);
+	__debugfs_register("dl_", rx, dentry);
+	__debugfs_register("dl_", fw, dentry);
+
+	return 0;
+
+error:
+	debugfs_remove_recursive(i2400ms->debugfs_dentry);
+	return result;
+}
+
+
+/*
+ * Probe a i2400m interface and register it
+ *
+ * @func:    SDIO function
+ * @id:      SDIO device ID
+ * @returns: 0 if ok, < 0 errno code on error.
+ *
+ * Alloc a net device, initialize the bus-specific details and then
+ * calls the bus-generic initialization routine. That will register
+ * the wimax and netdev devices, upload the firmware [using
+ * _bus_bm_*()], call _bus_dev_start() to finalize the setup of the
+ * communication with the device and then will start to talk to it to
+ * finnish setting it up.
+ *
+ * Initialization is tricky; some instances of the hw are packed with
+ * others in a way that requires a third driver that enables the WiMAX
+ * function. In those cases, we can't enable the SDIO function and
+ * we'll return with -ENODEV. When the driver that enables the WiMAX
+ * function does its thing, it has to do a bus_rescan_devices() on the
+ * SDIO bus so this driver is called again to enumerate the WiMAX
+ * function.
+ */
+static
+int i2400ms_probe(struct sdio_func *func,
+		  const struct sdio_device_id *id)
+{
+	int result;
+	struct net_device *net_dev;
+	struct device *dev = &func->dev;
+	struct i2400m *i2400m;
+	struct i2400ms *i2400ms;
+
+	/* Allocate instance [calls i2400m_netdev_setup() on it]. */
+	result = -ENOMEM;
+	net_dev = alloc_netdev(sizeof(*i2400ms), "wmx%d",
+			       i2400ms_netdev_setup);
+	if (net_dev == NULL) {
+		dev_err(dev, "no memory for network device instance\n");
+		goto error_alloc_netdev;
+	}
+	SET_NETDEV_DEV(net_dev, dev);
+	i2400m = net_dev_to_i2400m(net_dev);
+	i2400ms = container_of(i2400m, struct i2400ms, i2400m);
+	i2400m->wimax_dev.net_dev = net_dev;
+	i2400ms->func = func;
+	sdio_set_drvdata(func, i2400ms);
+
+	i2400m->bus_tx_block_size = I2400MS_BLK_SIZE;
+	i2400m->bus_pl_size_max = I2400MS_PL_SIZE_MAX;
+	i2400m->bus_dev_start = i2400ms_bus_dev_start;
+	i2400m->bus_dev_stop = i2400ms_bus_dev_stop;
+	i2400m->bus_tx_kick = i2400ms_bus_tx_kick;
+	i2400m->bus_reset = i2400ms_bus_reset;
+	i2400m->bus_bm_cmd_send = i2400ms_bus_bm_cmd_send;
+	i2400m->bus_bm_wait_for_ack = i2400ms_bus_bm_wait_for_ack;
+	i2400m->bus_fw_name = I2400MS_FW_FILE_NAME;
+	i2400m->bus_bm_mac_addr_impaired = 1;
+
+	result = i2400ms_enable_function(i2400ms->func);
+	if (result < 0) {
+		dev_err(dev, "Cannot enable SDIO function: %d\n", result);
+		goto error_func_enable;
+	}
+
+	sdio_claim_host(func);
+	result = sdio_set_block_size(func, I2400MS_BLK_SIZE);
+	if (result < 0) {
+		dev_err(dev, "Failed to set block size: %d\n", result);
+		goto error_set_blk_size;
+	}
+	sdio_release_host(func);
+
+	result = i2400m_setup(i2400m, I2400M_BRI_NO_REBOOT);
+	if (result < 0) {
+		dev_err(dev, "cannot setup device: %d\n", result);
+		goto error_setup;
+	}
+
+	result = i2400ms_debugfs_add(i2400ms);
+	if (result < 0) {
+		dev_err(dev, "cannot create SDIO debugfs: %d\n",
+			result);
+		goto error_debugfs_add;
+	}
+	return 0;
+
+error_debugfs_add:
+	i2400m_release(i2400m);
+error_setup:
+	sdio_set_drvdata(func, NULL);
+	sdio_claim_host(func);
+error_set_blk_size:
+	sdio_disable_func(func);
+	sdio_release_host(func);
+error_func_enable:
+	free_netdev(net_dev);
+error_alloc_netdev:
+	return result;
+}
+
+
+static
+void i2400ms_remove(struct sdio_func *func)
+{
+	struct device *dev = &func->dev;
+	struct i2400ms *i2400ms = sdio_get_drvdata(func);
+	struct i2400m *i2400m = &i2400ms->i2400m;
+	struct net_device *net_dev = i2400m->wimax_dev.net_dev;
+
+	d_fnstart(3, dev, "SDIO func %p\n", func);
+	debugfs_remove_recursive(i2400ms->debugfs_dentry);
+	i2400m_release(i2400m);
+	sdio_set_drvdata(func, NULL);
+	sdio_claim_host(func);
+	sdio_disable_func(func);
+	sdio_release_host(func);
+	free_netdev(net_dev);
+	d_fnend(3, dev, "SDIO func %p\n", func);
+}
+
+enum {
+	I2400MS_INTEL_VID = 0x89,
+};
+
+static
+const struct sdio_device_id i2400ms_sdio_ids[] = {
+	/* Intel: i2400m WiMAX over SDIO */
+	{ SDIO_DEVICE(I2400MS_INTEL_VID, 0x1402) },
+	{ }, 			/* end: all zeroes */
+};
+MODULE_DEVICE_TABLE(sdio, i2400ms_sdio_ids);
+
+
+static
+struct sdio_driver i2400m_sdio_driver = {
+	.name		= KBUILD_MODNAME,
+	.probe		= i2400ms_probe,
+	.remove		= i2400ms_remove,
+	.id_table	= i2400ms_sdio_ids,
+};
+
+
+static
+int __init i2400ms_driver_init(void)
+{
+	return sdio_register_driver(&i2400m_sdio_driver);
+}
+module_init(i2400ms_driver_init);
+
+
+static
+void __exit i2400ms_driver_exit(void)
+{
+	flush_scheduled_work();	/* for the stuff we schedule */
+	sdio_unregister_driver(&i2400m_sdio_driver);
+}
+module_exit(i2400ms_driver_exit);
+
+
+MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
+MODULE_DESCRIPTION("Intel 2400M WiMAX networking for SDIO");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE(I2400MS_FW_FILE_NAME);