[PATCH net-next 0/3] Driver for TI CC2520 Radio chip

[PATCH net-next 0/3] Driver for TI CC2520 Radio chip

[Varka Bhadram]

This patch series adds the support for cc2520 radio and
provides device tree bindings for cc2520

Varka Bhadram (3):
  ieee802154: cc2520: driver for TI cc2520 radio
  ieee802154: cc2520: add driver to kernel build system
  devicetree: add devicetree bindings for cc2520 driver

 .../devicetree/bindings/net/ieee802154/cc2520.txt  |   26 +
 drivers/net/ieee802154/Kconfig                     |   11 +
 drivers/net/ieee802154/Makefile                    |    1 +
 drivers/net/ieee802154/cc2520.c                    |  805 ++++++++++++++++++++
 include/linux/spi/cc2520.h                         |  176 +++++
 5 files changed, 1019 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ieee802154/cc2520.txt
 create mode 100644 drivers/net/ieee802154/cc2520.c
 create mode 100644 include/linux/spi/cc2520.h

-- 
1.7.9.5

[PATCH net-next 1/3] ieee802154: cc2520: driver for TI cc2520 radio

[Varka Bhadram]

Signed-off-by: Varka Bhadram <varkab@cdac.in>
---
 drivers/net/ieee802154/cc2520.c |  805 +++++++++++++++++++++++++++++++++++++++
 include/linux/spi/cc2520.h      |  176 +++++++++
 2 files changed, 981 insertions(+)
 create mode 100644 drivers/net/ieee802154/cc2520.c
 create mode 100644 include/linux/spi/cc2520.h

diff --git a/drivers/net/ieee802154/cc2520.c b/drivers/net/ieee802154/cc2520.c
new file mode 100644
index 0000000..e8b5993
--- /dev/null
+++ b/drivers/net/ieee802154/cc2520.c
@@ -0,0 +1,805 @@
+/* Driver for TI CC2520 802.15.4 Wireless-PAN Networking controller
+ *
+ * Copyright (C) 2014 Varka Bhadram <varkab@cdac.in>
+ *		      Md.Jamal Mohiuddin <mjmohiuddin@cdac.in>
+ *		      P Sowjanya <sowjanyap@cdac.in>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/cc2520.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+
+#include <linux/skbuff.h>
+
+#include <linux/pinctrl/consumer.h>
+
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+
+#include <net/mac802154.h>
+#include <net/wpan-phy.h>
+
+#define	SPI_COMMAND_BUFFER	3
+#define	HIGH			1
+#define	LOW			0
+#define	STATE_IDLE		0
+
+/*Driver private information */
+struct cc2520_private {
+	struct spi_device *spi;
+
+	struct ieee802154_dev *dev;
+
+	u8 *buf;
+	struct mutex buffer_mutex;
+
+	unsigned is_tx:1;
+	int fifo_irq;
+
+	int fifo_pin;
+	int fifop_pin;
+
+	struct work_struct fifop_irqwork;
+
+	spinlock_t lock;
+
+	struct completion tx_complete;
+};
+
+/*Generic Functions*/
+static int cc2520_cmd_strobe(struct cc2520_private *priv,
+						u8 cmd)
+{
+	int ret;
+	u8 status = 0xff;
+	struct spi_message msg;
+	struct spi_transfer xfer = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->buf[xfer.len++] = cmd;
+	dev_vdbg(&priv->spi->dev,
+			"command strobe buf[0] = %02x\n",
+			priv->buf[0]);
+
+	ret = spi_sync(priv->spi, &msg);
+	if (!ret)
+		status = priv->buf[0];
+	dev_vdbg(&priv->spi->dev,
+			"buf[0] = %02x\n", priv->buf[0]);
+	mutex_unlock(&priv->buffer_mutex);
+
+	return ret;
+}
+
+static int cc2520_get_status(struct cc2520_private *priv,
+						u8 *status)
+{
+	int ret;
+	struct spi_message msg;
+	struct spi_transfer xfer = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->buf[xfer.len++] = CC2520_CMD_SNOP;
+	dev_vdbg(&priv->spi->dev,
+			"get status command buf[0] = %02x\n", priv->buf[0]);
+
+	ret = spi_sync(priv->spi, &msg);
+	if (!ret)
+		*status = priv->buf[0];
+	dev_vdbg(&priv->spi->dev,
+			"buf[0] = %02x\n", priv->buf[0]);
+	mutex_unlock(&priv->buffer_mutex);
+
+	return ret;
+}
+
+static int cc2520_write_register(struct cc2520_private *priv,
+					u8 reg, u8 value)
+{
+	int status;
+	struct spi_message msg;
+	struct spi_transfer xfer = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+
+	if (reg <= CC2520_FREG_MASK) {
+		priv->buf[xfer.len++] = CC2520_CMD_REGISTER_WRITE | reg;
+		priv->buf[xfer.len++] = value;
+	} else {
+		priv->buf[xfer.len++] = CC2520_CMD_MEMORY_WRITE;
+		priv->buf[xfer.len++] = reg;
+		priv->buf[xfer.len++] = value;
+	}
+	status = spi_sync(priv->spi, &msg);
+	if (msg.status)
+		status = msg.status;
+
+	mutex_unlock(&priv->buffer_mutex);
+
+	return status;
+}
+
+static int cc2520_read_register(struct cc2520_private *priv,
+				u8 reg, u8 *data)
+{
+
+	int status;
+	struct spi_message msg;
+	struct spi_transfer xfer1 = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+
+	struct spi_transfer xfer2 = {
+		.len = 1,
+		.rx_buf = data,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer1, &msg);
+	spi_message_add_tail(&xfer2, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->buf[xfer1.len++] = CC2520_CMD_MEMORY_READ;
+	priv->buf[xfer1.len++] = reg;
+
+	status = spi_sync(priv->spi, &msg);
+	dev_dbg(&priv->spi->dev,
+			"spi status = %d\n", status);
+	if (msg.status)
+		status = msg.status;
+
+	mutex_unlock(&priv->buffer_mutex);
+
+	return status;
+}
+
+static int cc2520_write_txfifo(struct cc2520_private *priv,
+			u8 *data, u8 len)
+{
+	int status;
+
+	/*
+	 *length byte must include FCS even
+	 *if it is calculated in the hardware
+	 */
+	int len_byte = len + 2;
+
+	struct spi_message msg;
+
+	struct spi_transfer xfer_head = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+	struct spi_transfer xfer_len = {
+		.len = 1,
+		.tx_buf = &len_byte,
+	};
+	struct spi_transfer xfer_buf = {
+		.len = len,
+		.tx_buf = data,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer_head, &msg);
+	spi_message_add_tail(&xfer_len, &msg);
+	spi_message_add_tail(&xfer_buf, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->buf[xfer_head.len++] = CC2520_CMD_TXBUF;
+	dev_vdbg(&priv->spi->dev,
+			"TX_FIFO cmd buf[0] = %02x\n", priv->buf[0]);
+
+	status = spi_sync(priv->spi, &msg);
+	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
+	if (msg.status)
+		status = msg.status;
+	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
+	dev_vdbg(&priv->spi->dev, "buf[0] = %02x\n", priv->buf[0]);
+	mutex_unlock(&priv->buffer_mutex);
+
+	return status;
+}
+
+static int cc2520_read_rxfifo(struct cc2520_private *priv,
+			u8 *data, u8 *len, u8 *lqi)
+{
+	int status;
+	struct spi_message msg;
+
+	struct spi_transfer xfer_head = {
+		.len = 0,
+		.tx_buf = priv->buf,
+		.rx_buf = priv->buf,
+	};
+	struct spi_transfer xfer_buf = {
+		.len = *len,
+		.rx_buf = data,
+	};
+
+	spi_message_init(&msg);
+	spi_message_add_tail(&xfer_head, &msg);
+	spi_message_add_tail(&xfer_buf, &msg);
+
+	mutex_lock(&priv->buffer_mutex);
+	priv->buf[xfer_head.len++] = CC2520_CMD_RXBUF;
+
+	dev_vdbg(&priv->spi->dev, "read rxfifo buf[0] = %02x\n", priv->buf[0]);
+	dev_vdbg(&priv->spi->dev, "buf[1] = %02x\n", priv->buf[1]);
+
+	status = spi_sync(priv->spi, &msg);
+	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
+	if (msg.status)
+		status = msg.status;
+	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
+	dev_vdbg(&priv->spi->dev,
+				"return status buf[0] = %02x\n", priv->buf[0]);
+	dev_vdbg(&priv->spi->dev, "length buf[1] = %02x\n", priv->buf[1]);
+
+	*lqi = data[priv->buf[1] - 1] & 0x7f;
+
+	mutex_unlock(&priv->buffer_mutex);
+
+	return status;
+}
+
+static int cc2520_start(struct ieee802154_dev *dev)
+{
+	return cc2520_cmd_strobe(dev->priv, CC2520_CMD_SRXON);
+}
+
+static void cc2520_stop(struct ieee802154_dev *dev)
+{
+	cc2520_cmd_strobe(dev->priv, CC2520_CMD_SRFOFF);
+}
+
+static int cc2520_tx(struct ieee802154_dev *dev, struct sk_buff *skb)
+{
+	struct cc2520_private *priv = dev->priv;
+	unsigned long flags;
+	int rc;
+	u8 status = 0;
+
+	rc = cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHTX);
+	if (rc)
+		goto err_tx;
+
+	rc = cc2520_write_txfifo(priv, skb->data, skb->len);
+	if (rc)
+		goto err_tx;
+
+	rc = cc2520_get_status(priv, &status);
+	if (rc)
+		goto err_tx;
+
+	if (status & CC2520_STATUS_TX_UNDERFLOW) {
+		dev_err(&priv->spi->dev, "cc2520 tx underflow exception\n");
+		goto err_tx;
+	}
+
+	spin_lock_irqsave(&priv->lock, flags);
+	BUG_ON(priv->is_tx);
+	priv->is_tx = 1;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	rc = cc2520_cmd_strobe(priv, CC2520_CMD_STXONCCA);
+	if (rc)
+		goto err;
+
+	rc = wait_for_completion_interruptible(&priv->tx_complete);
+	if (rc < 0)
+		goto err;
+
+	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHTX);
+	cc2520_cmd_strobe(priv, CC2520_CMD_SRXON);
+
+	return rc;
+err:
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->is_tx = 0;
+	spin_unlock_irqrestore(&priv->lock, flags);
+err_tx:
+	return rc;
+}
+
+
+static int cc2520_rx(struct cc2520_private *priv)
+{
+	u8 len = 0, lqi = 0, bytes = 1;
+	struct sk_buff *skb;
+
+	cc2520_read_rxfifo(priv, &len, &bytes, &lqi);
+
+	skb = alloc_skb(len, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	cc2520_read_rxfifo(priv, skb_put(skb, len), &len, &lqi);
+	if (len < 2) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	skb_trim(skb, skb->len - 2);
+
+	ieee802154_rx_irqsafe(priv->dev, skb, lqi);
+
+	dev_vdbg(&priv->spi->dev, "RXFIFO: %x %x\n", len, lqi);
+
+	return 0;
+}
+
+static int cc2520_ed(struct ieee802154_dev *dev, u8 *level)
+{
+	struct cc2520_private *priv = dev->priv;
+	u8 status = 0xff;
+	u8 rssi;
+	int ret;
+
+	ret = cc2520_read_register(priv , CC2520_RSSISTAT, &status);
+	if (ret)
+		return ret;
+
+	if (status != RSSI_VALID) {
+		ret = -EINVAL;
+		return ret;
+	}
+
+	ret = cc2520_read_register(priv , CC2520_RSSI, &rssi);
+	if (ret)
+		return ret;
+
+	/* level = RSSI(rssi) - OFFSET [dBm] : offset is 76dBm*/
+	*level = rssi - RSSI_OFFSET;
+
+	return ret;
+}
+
+static int cc2520_set_channel(struct ieee802154_dev *dev,
+				int page, int channel)
+{
+	struct cc2520_private *priv = dev->priv;
+	int ret;
+
+	might_sleep();
+	dev_dbg(&priv->spi->dev, "trying to set channel\n");
+
+	BUG_ON(page != 0);
+	BUG_ON(channel < CC2520_MINCHANNEL);
+	BUG_ON(channel > CC2520_MAXCHANNEL);
+
+	ret = cc2520_write_register(priv, CC2520_FREQCTRL,
+					11 + 5*(channel - 11));
+
+	return ret;
+}
+
+static struct ieee802154_ops cc2520_ops = {
+	.owner = THIS_MODULE,
+	.start = cc2520_start,
+	.stop = cc2520_stop,
+	.xmit = cc2520_tx,
+	.ed = cc2520_ed,
+	.set_channel = cc2520_set_channel,
+};
+
+static int cc2520_register(struct cc2520_private *priv)
+{
+	int ret = -ENOMEM;
+
+	priv->dev = ieee802154_alloc_device(sizeof(*priv), &cc2520_ops);
+	if (!priv->dev)
+		goto err_ret;
+
+	priv->dev->priv = priv;
+	priv->dev->parent = &priv->spi->dev;
+	priv->dev->extra_tx_headroom = 0;
+
+	/* We do support only 2.4 Ghz */
+	priv->dev->phy->channels_supported[0] = 0x7FFF800;
+	priv->dev->flags = IEEE802154_HW_OMIT_CKSUM;
+
+	dev_vdbg(&priv->spi->dev, "registered cc2520\n");
+	ret = ieee802154_register_device(priv->dev);
+	if (ret)
+		goto err_free_device;
+
+	return 0;
+
+err_free_device:
+	ieee802154_free_device(priv->dev);
+err_ret:
+	return ret;
+}
+
+static void cc2520_unregister(struct cc2520_private *priv)
+{
+	ieee802154_unregister_device(priv->dev);
+	ieee802154_free_device(priv->dev);
+}
+
+static void cc2520_fifop_irqwork(struct work_struct *work)
+{
+	struct cc2520_private *priv
+		= container_of(work, struct cc2520_private, fifop_irqwork);
+
+	dev_dbg(&priv->spi->dev, "fifop interrupt received\n");
+
+	if (gpio_get_value(priv->fifo_pin))
+		cc2520_rx(priv);
+	else
+		dev_err(&priv->spi->dev, "rxfifo overflow\n");
+
+	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
+	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
+}
+
+static irqreturn_t cc2520_fifop_isr(int irq, void *data)
+{
+	struct cc2520_private *priv = data;
+
+	schedule_work(&priv->fifop_irqwork);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t cc2520_sfd_isr(int irq, void *data)
+{
+	struct cc2520_private *priv = data;
+
+	spin_lock(&priv->lock);
+	if (priv->is_tx) {
+		dev_dbg(&priv->spi->dev, "SFD for TX\n");
+		priv->is_tx = 0;
+		complete(&priv->tx_complete);
+	} else
+		dev_dbg(&priv->spi->dev, "SFD for RX\n");
+	spin_unlock(&priv->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int cc2520_hw_init(struct cc2520_private *priv)
+{
+	u8 status = 0, state = 0xff;
+	int ret;
+	int timeout = 100;
+
+	ret = cc2520_read_register(priv, CC2520_FSMSTAT1, &state);
+	if (ret)
+		goto err_ret;
+
+	if (state != STATE_IDLE) {
+		ret = -EINVAL;
+		return ret;
+	}
+
+	do {
+		ret = cc2520_get_status(priv, &status);
+		if (ret)
+			goto err_ret;
+
+		if (timeout-- <= 0) {
+			dev_err(&priv->spi->dev, "oscillator start failed!\n");
+			return ret;
+		}
+		udelay(1);
+	} while (!(status & CC2520_STATUS_XOSC32M_STABLE));
+
+	dev_vdbg(&priv->spi->dev, "oscillator successfully brought up\n");
+
+	/*Registers default value: section 28.1 in Datasheet*/
+	ret = cc2520_write_register(priv, CC2520_TXPOWER, 0xF7);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_CCACTRL0, 0x1A);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_MDMCTRL0, 0x85);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_MDMCTRL1, 0x14);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_RXCTRL, 0x3f);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FSCTRL, 0x5a);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FSCAL1, 0x2b);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_AGCCTRL1, 0x11);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_ADCTEST0, 0x10);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_ADCTEST1, 0x0e);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_ADCTEST2, 0x03);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FRMCTRL0, 0x60);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FRMCTRL1, 0x03);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FRMFILT0, 0x00);
+	if (ret)
+		goto err_ret;
+
+	ret = cc2520_write_register(priv, CC2520_FIFOPCTRL, 127);
+	if (ret)
+		goto err_ret;
+
+	return 0;
+
+err_ret:
+	return ret;
+}
+
+static struct cc2520_platform_data *
+cc2520_get_platform_data(struct spi_device *spi)
+{
+	struct cc2520_platform_data *pdata;
+	struct device_node __maybe_unused *np = spi->dev.of_node;
+	struct cc2520_private *priv = spi_get_drvdata(spi);
+
+	if (!IS_ENABLED(CONFIG_OF) || !np)
+		return spi->dev.platform_data;
+
+	pdata = devm_kzalloc(&spi->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		goto done;
+
+	pdata->fifo = of_get_named_gpio(np, "fifo-gpio", 0);
+	priv->fifo_pin = pdata->fifo;
+
+	pdata->fifop = of_get_named_gpio(np, "fifop-gpio", 0);
+	priv->fifop_pin = pdata->fifop;
+
+	pdata->sfd = of_get_named_gpio(np, "sfd-gpio", 0);
+	pdata->cca = of_get_named_gpio(np, "cca-gpio", 0);
+	pdata->vreg = of_get_named_gpio(np, "vreg-gpio", 0);
+	pdata->reset = of_get_named_gpio(np, "reset-gpio", 0);
+
+	spi->dev.platform_data = pdata;
+
+done:
+	return pdata;
+}
+
+/*Driver probe function*/
+static int cc2520_probe(struct spi_device *spi)
+{
+	struct cc2520_private *priv;
+	struct pinctrl *pinctrl;
+	struct cc2520_platform_data *pdata;
+	struct device_node __maybe_unused *np = spi->dev.of_node;
+	int ret;
+
+	priv = kzalloc(sizeof(struct cc2520_private), GFP_KERNEL);
+	if (!priv) {
+		ret = -ENOMEM;
+		goto err_free_local;
+	}
+
+	spi_set_drvdata(spi, priv);
+
+	pinctrl = devm_pinctrl_get_select_default(&spi->dev);
+	if (IS_ERR(pinctrl))
+		dev_warn(&spi->dev,
+			"pinctrl pins are not configured from the driver");
+
+	pdata = cc2520_get_platform_data(spi);
+	if (!pdata) {
+		dev_err(&spi->dev, "no platform data\n");
+		return -EINVAL;
+	}
+
+	mutex_init(&priv->buffer_mutex);
+	INIT_WORK(&priv->fifop_irqwork, cc2520_fifop_irqwork);
+	spin_lock_init(&priv->lock);
+	init_completion(&priv->tx_complete);
+
+	priv->spi = spi;
+
+	priv->buf = kzalloc(SPI_COMMAND_BUFFER, GFP_KERNEL);
+	if (!priv->buf) {
+		ret = -ENOMEM;
+		goto err_free_buf;
+	}
+
+	/*Request all the gpio's*/
+	if (gpio_is_valid(pdata->fifo)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->fifo, 
+					GPIOF_IN, "fifo");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	if (gpio_is_valid(pdata->cca)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->cca,
+					GPIOF_IN, "cca");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	if (gpio_is_valid(pdata->fifop)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->fifop,
+					GPIOF_IN, "fifop");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	if (gpio_is_valid(pdata->sfd)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->sfd,
+					GPIOF_IN, "sfd");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	if (gpio_is_valid(pdata->reset)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->reset,
+					GPIOF_OUT_INIT_LOW, "reset");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	if (gpio_is_valid(pdata->vreg)) {
+		ret = devm_gpio_request_one(&spi->dev, pdata->vreg,
+					GPIOF_OUT_INIT_LOW, "vreg");
+		if (ret)
+			goto err_hw_init;
+	}
+
+	gpio_set_value(pdata->vreg, HIGH);
+	udelay(100);
+
+	gpio_set_value(pdata->reset, HIGH);
+	udelay(200);
+
+	ret = cc2520_hw_init(priv);
+	if (ret)
+		goto err_hw_init;
+
+	/*Set up fifop interrupt */
+	priv->fifo_irq = gpio_to_irq(pdata->fifop);
+	ret = devm_request_irq(&spi->dev,
+				priv->fifo_irq,
+				cc2520_fifop_isr,
+				IRQF_TRIGGER_RISING,
+				dev_name(&spi->dev),
+				priv);
+	if (ret) {
+		dev_err(&spi->dev, "could not get fifop irq\n");
+		goto err_hw_init;
+	}
+
+	/*Set up sfd interrupt*/
+	ret = devm_request_irq(&spi->dev,
+				gpio_to_irq(pdata->sfd),
+				cc2520_sfd_isr,
+				IRQF_TRIGGER_FALLING,
+				dev_name(&spi->dev),
+				priv);
+	if (ret) {
+		dev_err(&spi->dev, "could not get sfd irq\n");
+		goto err_hw_init;
+	}
+
+	ret = cc2520_register(priv);
+	if (ret)
+		goto err_hw_init;
+
+	return 0;
+
+err_hw_init:
+	mutex_destroy(&priv->buffer_mutex);
+	flush_work(&priv->fifop_irqwork);
+
+err_free_buf:
+	kfree(priv->buf);
+
+err_free_local:
+	kfree(priv);
+
+	return ret;
+}
+
+/*Driver remove function*/
+static int cc2520_remove(struct spi_device *spi)
+{
+	struct cc2520_private *priv = spi_get_drvdata(spi);
+
+	cc2520_unregister(priv);
+
+	mutex_destroy(&priv->buffer_mutex);
+	flush_work(&priv->fifop_irqwork);
+
+	kfree(priv->buf);
+	kfree(priv);
+
+	return 0;
+}
+
+static const struct spi_device_id cc2520_ids[] = {
+	{"cc2520", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(spi, cc2520_ids);
+
+static const struct of_device_id cc2520_of_ids[] = {
+	{.compatible = "ti,cc2520", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, cc2520_of_ids);
+
+/*SPI Driver Structure*/
+static struct spi_driver cc2520_driver = {
+	.driver = {
+		.name = "cc2520",
+		.bus = &spi_bus_type,
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(cc2520_of_ids),
+	},
+	.id_table = cc2520_ids,
+	.probe = cc2520_probe,
+	.remove = cc2520_remove,
+};
+module_spi_driver(cc2520_driver);
+
+MODULE_DESCRIPTION("CC2520 Transceiver Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/cc2520.h b/include/linux/spi/cc2520.h
new file mode 100644
index 0000000..68a2c88
--- /dev/null
+++ b/include/linux/spi/cc2520.h
@@ -0,0 +1,176 @@
+#ifndef __CC2520_H
+#define __CC2520_H
+
+#define RSSI_VALID		0
+#define RSSI_OFFSET		78
+#define CC2520_FREG_MASK	0x3F
+
+struct cc2520_platform_data {
+	int fifo;
+	int fifop;
+	int cca;
+	int sfd;
+	int reset;
+	int vreg;
+};
+
+enum cc2520_memory_size {
+	CC2520_RAM_SIZE		= 640,
+	CC2520_FIFO_SIZE	= 128,
+};
+
+enum cc2520_address {
+	CC2520RAM_TXFIFO	= 0x100,
+	CC2520RAM_RXFIFO	= 0x180,
+	CC2520RAM_IEEEADDR	= 0x3EA,
+	CC2520RAM_PANID		= 0x3F2,
+	CC2520RAM_SHORTADDR	= 0x3F4,
+};
+
+/*status byte values */
+#define	CC2520_STATUS_XOSC32M_STABLE	(1 << 7)
+#define	CC2520_STATUS_RSSI_VALID	(1 << 6)
+#define	CC2520_STATUS_TX_UNDERFLOW	(1 << 3)
+
+/*IEEE 802.15.4 defined constants (2.4 GHz logical channels) */
+#define CC2520_MINCHANNEL		11
+#define CC2520_MAXCHANNEL		26
+#define CC2520_CHANNEL_SPACING		5
+
+/*command strobes*/
+#define	CC2520_CMD_SNOP		0x00
+#define	CC2520_CMD_IBUFLD		0x02
+#define	CC2520_CMD_SIBUFEX		0x03
+#define	CC2520_CMD_SSAMPLECCA		0x04
+#define	CC2520_CMD_SRES			0x0f
+#define	CC2520_CMD_MEMORY_MASK		0x0f
+#define	CC2520_CMD_MEMORY_READ		0x10
+#define	CC2520_CMD_MEMORY_WRITE		0x20
+#define	CC2520_CMD_RXBUF		0x30
+#define	CC2520_CMD_RXBUFCP		0x38
+#define	CC2520_CMD_RXBUFMOV		0x32
+#define	CC2520_CMD_TXBUF		0x3A
+#define	CC2520_CMD_TXBUFCP		0x3E
+#define	CC2520_CMD_RANDOM		0x3C
+#define	CC2520_CMD_SXOSCON		0x40
+#define	CC2520_CMD_STXCAL		0x41
+#define	CC2520_CMD_SRXON		0x42
+#define	CC2520_CMD_STXON		0x43
+#define	CC2520_CMD_STXONCCA		0x44
+#define	CC2520_CMD_SRFOFF		0x45
+#define	CC2520_CMD_SXOSCOFF		0x46
+#define	CC2520_CMD_SFLUSHRX		0x47
+#define	CC2520_CMD_SFLUSHTX		0x48
+#define	CC2520_CMD_SACK			0x49
+#define	CC2520_CMD_SACKPEND		0x4A
+#define	CC2520_CMD_SNACK		0x4B
+#define	CC2520_CMD_SRXMASKBITSET	0x4C
+#define	CC2520_CMD_SRXMASKBITCLR	0x4D
+#define	CC2520_CMD_RXMASKAND		0x4E
+#define	CC2520_CMD_RXMASKOR		0x4F
+#define	CC2520_CMD_MEMCP		0x50
+#define	CC2520_CMD_MEMCPR		0x52
+#define	CC2520_CMD_MEMXCP		0x54
+#define	CC2520_CMD_MEMXWR		0x56
+#define	CC2520_CMD_BCLR			0x58
+#define	CC2520_CMD_BSET			0x59
+#define	CC2520_CMD_CTR_UCTR		0x60
+#define	CC2520_CMD_CBCMAC		0x64
+#define	CC2520_CMD_UCBCMAC		0x66
+#define	CC2520_CMD_CCM			0x68
+#define	CC2520_CMD_UCCM			0x6A
+#define	CC2520_CMD_ECB			0x70
+#define	CC2520_CMD_ECBO			0x72
+#define	CC2520_CMD_ECBX			0x74
+#define	CC2520_CMD_INC			0x78
+#define	CC2520_CMD_ABORT		0x7F
+#define	CC2520_CMD_REGISTER_READ	0x80
+#define	CC2520_CMD_REGISTER_WRITE	0xC0
+
+/* status registers */
+#define	CC2520_CHIPID			0x40
+#define	CC2520_VERSION			0x42
+#define	CC2520_EXTCLOCK			0x44
+#define	CC2520_MDMCTRL0			0x46
+#define	CC2520_MDMCTRL1			0x47
+#define	CC2520_FREQEST			0x48
+#define	CC2520_RXCTRL			0x4A
+#define	CC2520_FSCTRL			0x4C
+#define	CC2520_FSCAL0			0x4E
+#define	CC2520_FSCAL1			0x4F
+#define	CC2520_FSCAL2			0x50
+#define	CC2520_FSCAL3			0x51
+#define	CC2520_AGCCTRL0			0x52
+#define	CC2520_AGCCTRL1			0x53
+#define	CC2520_AGCCTRL2			0x54
+#define	CC2520_AGCCTRL3			0x55
+#define	CC2520_ADCTEST0			0x56
+#define	CC2520_ADCTEST1			0x57
+#define	CC2520_ADCTEST2			0x58
+#define	CC2520_MDMTEST0			0x5A
+#define	CC2520_MDMTEST1			0x5B
+#define CC2520_DACTEST0			0x5C
+#define CC2520_DACTEST1			0x5D
+#define CC2520_ATEST			0x5E
+#define CC2520_DACTEST2			0x5F
+#define CC2520_PTEST0			0x60
+#define CC2520_PTEST1			0x61
+#define CC2520_RESERVED			0x62
+#define CC2520_DPUBIST			0x7A
+#define CC2520_ACTBIST			0x7C
+#define CC2520_RAMBIST			0x7E
+
+/*frame registers*/
+#define CC2520_FRMFILT0			0x00
+#define CC2520_FRMFILT1			0x01
+#define CC2520_SRCMATCH			0x02
+#define CC2520_SRCSHORTEN0		0x04
+#define CC2520_SRCSHORTEN1		0x05
+#define CC2520_SRCSHORTEN2		0x06
+#define CC2520_SRCEXTEN0		0x08
+#define CC2520_SRCEXTEN1		0x09
+#define CC2520_SRCEXTEN2		0x0A
+#define CC2520_FRMCTRL0			0x0C
+#define CC2520_FRMCTRL1			0x0D
+#define CC2520_RXENABLE0		0x0E
+#define CC2520_RXENABLE1		0x0F
+#define CC2520_EXCFLAG0			0x10
+#define CC2520_EXCFLAG1			0x11
+#define CC2520_EXCFLAG2			0x12
+#define CC2520_EXCMASKA0		0x14
+#define CC2520_EXCMASKA1		0x15
+#define CC2520_EXCMASKA2		0x16
+#define CC2520_EXCMASKB0		0x18
+#define CC2520_EXCMASKB1		0x19
+#define CC2520_EXCMASKB2		0x1A
+#define CC2520_EXCBINDX0		0x1C
+#define CC2520_EXCBINDX1		0x1D
+#define CC2520_EXCBINDY0		0x1E
+#define CC2520_EXCBINDY1		0x1F
+#define CC2520_GPIOCTRL0		0x20
+#define CC2520_GPIOCTRL1		0x21
+#define CC2520_GPIOCTRL2		0x22
+#define CC2520_GPIOCTRL3		0x23
+#define CC2520_GPIOCTRL4		0x24
+#define CC2520_GPIOCTRL5		0x25
+#define CC2520_GPIOPOLARITY		0x26
+#define CC2520_GPIOCTRL			0x28
+#define CC2520_DPUCON			0x2A
+#define CC2520_DPUSTAT			0x2C
+#define CC2520_FREQCTRL			0x2E
+#define CC2520_FREQTUNE			0x2F
+#define CC2520_TXPOWER			0x30
+#define CC2520_TXCTRL			0x31
+#define CC2520_FSMSTAT0			0x32
+#define CC2520_FSMSTAT1			0x33
+#define CC2520_FIFOPCTRL		0x34
+#define CC2520_FSMCTRL			0x35
+#define CC2520_CCACTRL0			0x36
+#define CC2520_CCACTRL1			0x37
+#define CC2520_RSSI			0x38
+#define CC2520_RSSISTAT			0x39
+#define CC2520_RXFIRST			0x3C
+#define CC2520_RXFIFOCNT		0x3E
+#define CC2520_TXFIFOCNT		0x3F
+
+#endif
-- 
1.7.9.5

Re: [Linux-zigbee-devel] [PATCH net-next 1/3] ieee802154: cc2520: driver for TI cc2520 radio

[Alexander Aring]

Hi Varka,

On Mon, Jun 16, 2014 at 10:21:56AM +0530, Varka Bhadram wrote:
> 

Maybe some more information about this chip in the commit msg?

> Signed-off-by: Varka Bhadram <varkab@cdac.in>
> ---
>  drivers/net/ieee802154/cc2520.c |  805 +++++++++++++++++++++++++++++++++++++++
>  include/linux/spi/cc2520.h      |  176 +++++++++
>  2 files changed, 981 insertions(+)
>  create mode 100644 drivers/net/ieee802154/cc2520.c
>  create mode 100644 include/linux/spi/cc2520.h
> 
> diff --git a/drivers/net/ieee802154/cc2520.c b/drivers/net/ieee802154/cc2520.c
> new file mode 100644
> index 0000000..e8b5993
> --- /dev/null
> +++ b/drivers/net/ieee802154/cc2520.c
> @@ -0,0 +1,805 @@
> +/* Driver for TI CC2520 802.15.4 Wireless-PAN Networking controller
> + *
> + * Copyright (C) 2014 Varka Bhadram <varkab@cdac.in>
> + *		      Md.Jamal Mohiuddin <mjmohiuddin@cdac.in>
> + *		      P Sowjanya <sowjanyap@cdac.in>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/gpio.h>
> +#include <linux/delay.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/cc2520.h>
> +#include <linux/workqueue.h>
> +#include <linux/interrupt.h>
> +
> +#include <linux/skbuff.h>
> +
> +#include <linux/pinctrl/consumer.h>
> +
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_gpio.h>
> +
> +#include <net/mac802154.h>
> +#include <net/wpan-phy.h>
> +
> +#define	SPI_COMMAND_BUFFER	3
> +#define	HIGH			1
> +#define	LOW			0
> +#define	STATE_IDLE		0
> +
> +/*Driver private information */
> +struct cc2520_private {
> +	struct spi_device *spi;
> +
> +	struct ieee802154_dev *dev;
> +
> +	u8 *buf;
> +	struct mutex buffer_mutex;
> +
> +	unsigned is_tx:1;
> +	int fifo_irq;
> +
> +	int fifo_pin;
> +	int fifop_pin;
> +
> +	struct work_struct fifop_irqwork;
> +
> +	spinlock_t lock;
> +
> +	struct completion tx_complete;
> +};
> +
> +/*Generic Functions*/
> +static int cc2520_cmd_strobe(struct cc2520_private *priv,
> +						u8 cmd)
> +{
> +	int ret;
> +	u8 status = 0xff;
> +	struct spi_message msg;
> +	struct spi_transfer xfer = {
> +		.len = 0,
> +		.tx_buf = priv->buf,
> +		.rx_buf = priv->buf,
> +	};
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfer, &msg);

I see, you maybe looked at others drivers like at86rf230 and see what
they do there. I really don't like the lowlevel spi calls in the others
drivers. There are spi helper functions like 'spi_write_then_read' look
in drivers/spi/spi.c for the helper functions. Then you don't need the
buffer_mutex also.

> +
> +	mutex_lock(&priv->buffer_mutex);
> +	priv->buf[xfer.len++] = cmd;
> +	dev_vdbg(&priv->spi->dev,
> +			"command strobe buf[0] = %02x\n",
> +			priv->buf[0]);
> +
> +	ret = spi_sync(priv->spi, &msg);
> +	if (!ret)
> +		status = priv->buf[0];
> +	dev_vdbg(&priv->spi->dev,
> +			"buf[0] = %02x\n", priv->buf[0]);
> +	mutex_unlock(&priv->buffer_mutex);
> +
> +	return ret;
> +}
> +

....

> +
> +static void cc2520_unregister(struct cc2520_private *priv)
> +{
> +	ieee802154_unregister_device(priv->dev);
> +	ieee802154_free_device(priv->dev);
> +}

Only used in remove callback of module. It's small enough to do this in
the remove callback.

> +
> +static void cc2520_fifop_irqwork(struct work_struct *work)
> +{
> +	struct cc2520_private *priv
> +		= container_of(work, struct cc2520_private, fifop_irqwork);
> +
> +	dev_dbg(&priv->spi->dev, "fifop interrupt received\n");
> +
> +	if (gpio_get_value(priv->fifo_pin))
> +		cc2520_rx(priv);
> +	else
> +		dev_err(&priv->spi->dev, "rxfifo overflow\n");
> +
> +	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
> +	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
> +}
> +
> +static irqreturn_t cc2520_fifop_isr(int irq, void *data)
> +{
> +	struct cc2520_private *priv = data;
> +
> +	schedule_work(&priv->fifop_irqwork);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t cc2520_sfd_isr(int irq, void *data)
> +{
> +	struct cc2520_private *priv = data;
> +
> +	spin_lock(&priv->lock);

You need to use here spin_lock_irqsave and spin_unlock_irqrestore here.
Please verify you locking with PROVE_LOCKING enabled in your kernel.

In your xmit callback you use a irqsave spinlocks there. You need always
save to the "strongest" context which is a interrupt in your case.

> +	if (priv->is_tx) {
> +		dev_dbg(&priv->spi->dev, "SFD for TX\n");
> +		priv->is_tx = 0;
> +		complete(&priv->tx_complete);
> +	} else
> +		dev_dbg(&priv->spi->dev, "SFD for RX\n");

make brackets in the else branch if you have brackets in the "if" branch.

You don't need to lock all the things here I think:

--snip
	spin_lock_irqsave(&priv->lock, flags);
	if (priv->is_tx) {
		priv->is_tx = 0;
		spin_unlock_irqrestore(&priv->lock, flags);
		dev_dbg(&priv->spi->dev, "SFD for TX\n");
		complete(&priv->tx_complete);
	} else {
		spin_unlock_irqrestore(&priv->lock, flags);
		dev_dbg(&priv->spi->dev, "SFD for RX\n");
	}
--snap

> +	spin_unlock(&priv->lock);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int cc2520_hw_init(struct cc2520_private *priv)
> +{
> +	u8 status = 0, state = 0xff;
> +	int ret;
> +	int timeout = 100;
> +
> +	ret = cc2520_read_register(priv, CC2520_FSMSTAT1, &state);
> +	if (ret)
> +		goto err_ret;
> +
> +	if (state != STATE_IDLE) {
> +		ret = -EINVAL;
> +		return ret;

return -EINVAL? saves the brackets ;)

> +	}
> +
> +	do {
> +		ret = cc2520_get_status(priv, &status);
> +		if (ret)
> +			goto err_ret;
> +
> +		if (timeout-- <= 0) {
> +			dev_err(&priv->spi->dev, "oscillator start failed!\n");
> +			return ret;
> +		}
> +		udelay(1);
> +	} while (!(status & CC2520_STATUS_XOSC32M_STABLE));
> +
> +	dev_vdbg(&priv->spi->dev, "oscillator successfully brought up\n");
> +
> +	/*Registers default value: section 28.1 in Datasheet*/
> +	ret = cc2520_write_register(priv, CC2520_TXPOWER, 0xF7);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_CCACTRL0, 0x1A);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_MDMCTRL0, 0x85);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_MDMCTRL1, 0x14);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_RXCTRL, 0x3f);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FSCTRL, 0x5a);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FSCAL1, 0x2b);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_AGCCTRL1, 0x11);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_ADCTEST0, 0x10);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_ADCTEST1, 0x0e);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_ADCTEST2, 0x03);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FRMCTRL0, 0x60);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FRMCTRL1, 0x03);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FRMFILT0, 0x00);
> +	if (ret)
> +		goto err_ret;
> +
> +	ret = cc2520_write_register(priv, CC2520_FIFOPCTRL, 127);
> +	if (ret)
> +		goto err_ret;
> +
> +	return 0;
> +
> +err_ret:
> +	return ret;
> +}
> +
> +static struct cc2520_platform_data *
> +cc2520_get_platform_data(struct spi_device *spi)
> +{
> +	struct cc2520_platform_data *pdata;
> +	struct device_node __maybe_unused *np = spi->dev.of_node;
> +	struct cc2520_private *priv = spi_get_drvdata(spi);
> +
> +	if (!IS_ENABLED(CONFIG_OF) || !np)
> +		return spi->dev.platform_data;
> +
> +	pdata = devm_kzalloc(&spi->dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		goto done;
> +
> +	pdata->fifo = of_get_named_gpio(np, "fifo-gpio", 0);
> +	priv->fifo_pin = pdata->fifo;
> +
> +	pdata->fifop = of_get_named_gpio(np, "fifop-gpio", 0);
> +	priv->fifop_pin = pdata->fifop;
> +
> +	pdata->sfd = of_get_named_gpio(np, "sfd-gpio", 0);
> +	pdata->cca = of_get_named_gpio(np, "cca-gpio", 0);
> +	pdata->vreg = of_get_named_gpio(np, "vreg-gpio", 0);
> +	pdata->reset = of_get_named_gpio(np, "reset-gpio", 0);
> +
> +	spi->dev.platform_data = pdata;
> +
> +done:
> +	return pdata;
> +}
> +
> +/*Driver probe function*/
> +static int cc2520_probe(struct spi_device *spi)
> +{
> +	struct cc2520_private *priv;
> +	struct pinctrl *pinctrl;
> +	struct cc2520_platform_data *pdata;
> +	struct device_node __maybe_unused *np = spi->dev.of_node;
> +	int ret;
> +
> +	priv = kzalloc(sizeof(struct cc2520_private), GFP_KERNEL);
> +	if (!priv) {
> +		ret = -ENOMEM;
> +		goto err_free_local;
> +	}

why not devm_ calls?

> +
> +	spi_set_drvdata(spi, priv);
> +
> +	pinctrl = devm_pinctrl_get_select_default(&spi->dev);
> +	if (IS_ERR(pinctrl))
> +		dev_warn(&spi->dev,
> +			"pinctrl pins are not configured from the driver");
> +
> +	pdata = cc2520_get_platform_data(spi);
> +	if (!pdata) {
> +		dev_err(&spi->dev, "no platform data\n");
> +		return -EINVAL;
memory leak of priv here.

> +	}
> +
> +	mutex_init(&priv->buffer_mutex);
> +	INIT_WORK(&priv->fifop_irqwork, cc2520_fifop_irqwork);

I really don't like also the workqueue here. The at86rf230 use also a
workqueue but the mrf24j40 uses 'devm_request_threaded_irq'. A threaded
irq can also handle sync spi calls.

> +	spin_lock_init(&priv->lock);
> +	init_completion(&priv->tx_complete);
> +
> +	priv->spi = spi;
> +
> +	priv->buf = kzalloc(SPI_COMMAND_BUFFER, GFP_KERNEL);
> +	if (!priv->buf) {
> +		ret = -ENOMEM;
> +		goto err_free_buf;
> +	}
> +
> +	/*Request all the gpio's*/
> +	if (gpio_is_valid(pdata->fifo)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->fifo, 
> +					GPIOF_IN, "fifo");
> +		if (ret)
> +			goto err_hw_init;
> +	}
> +
> +	if (gpio_is_valid(pdata->cca)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->cca,
> +					GPIOF_IN, "cca");
> +		if (ret)
> +			goto err_hw_init;
> +	}
> +
> +	if (gpio_is_valid(pdata->fifop)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->fifop,
> +					GPIOF_IN, "fifop");
> +		if (ret)
> +			goto err_hw_init;
> +	}
> +
> +	if (gpio_is_valid(pdata->sfd)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->sfd,
> +					GPIOF_IN, "sfd");
> +		if (ret)
> +			goto err_hw_init;
> +	}
> +
> +	if (gpio_is_valid(pdata->reset)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->reset,
> +					GPIOF_OUT_INIT_LOW, "reset");
> +		if (ret)
> +			goto err_hw_init;
> +	}
> +
> +	if (gpio_is_valid(pdata->vreg)) {
> +		ret = devm_gpio_request_one(&spi->dev, pdata->vreg,
> +					GPIOF_OUT_INIT_LOW, "vreg");
> +		if (ret)
> +			goto err_hw_init;
> +	}

You should check on the not optional pins if you can request them. You
use in the above code the pins vreg, reset, fifo_irq, sfd. And this
failed if the gpio's are not valid.

means:

if (!gpio_is_valid(pdata->vreg)) {
	dev_err(....)
	ret = -EINVAL;
	goto ...;
}

on all pins which are needed to use your chip.

> +
> +	gpio_set_value(pdata->vreg, HIGH);
> +	udelay(100);
> +
> +	gpio_set_value(pdata->reset, HIGH);
> +	udelay(200);
> +
> +	ret = cc2520_hw_init(priv);
> +	if (ret)
> +		goto err_hw_init;
> +
> +	/*Set up fifop interrupt */
> +	priv->fifo_irq = gpio_to_irq(pdata->fifop);

why is fifo_irq in your "private data"? This is only used in this function.

> +	ret = devm_request_irq(&spi->dev,
> +				priv->fifo_irq,
> +				cc2520_fifop_isr,
> +				IRQF_TRIGGER_RISING,
> +				dev_name(&spi->dev),
> +				priv);
> +	if (ret) {
> +		dev_err(&spi->dev, "could not get fifop irq\n");
> +		goto err_hw_init;
> +	}
> +
> +	/*Set up sfd interrupt*/
> +	ret = devm_request_irq(&spi->dev,
> +				gpio_to_irq(pdata->sfd),
> +				cc2520_sfd_isr,
> +				IRQF_TRIGGER_FALLING,
> +				dev_name(&spi->dev),
> +				priv);
> +	if (ret) {
> +		dev_err(&spi->dev, "could not get sfd irq\n");
> +		goto err_hw_init;
> +	}
> +
> +	ret = cc2520_register(priv);
> +	if (ret)
> +		goto err_hw_init;
> +
> +	return 0;
> +
> +err_hw_init:
> +	mutex_destroy(&priv->buffer_mutex);
> +	flush_work(&priv->fifop_irqwork);
> +
> +err_free_buf:
> +	kfree(priv->buf);
> +
> +err_free_local:
> +	kfree(priv);
> +
> +	return ret;
> +}
> +
> +/*Driver remove function*/
> +static int cc2520_remove(struct spi_device *spi)
> +{
> +	struct cc2520_private *priv = spi_get_drvdata(spi);
> +
> +	cc2520_unregister(priv);
> +
> +	mutex_destroy(&priv->buffer_mutex);
> +	flush_work(&priv->fifop_irqwork);
> +
> +	kfree(priv->buf);
> +	kfree(priv);
> +
> +	return 0;
> +}
> +
> +static const struct spi_device_id cc2520_ids[] = {
> +	{"cc2520", 0},
You don't need to set the driver_data to 0. Simple:
	{ "cc2520", },

> +	{},
> +};
> +MODULE_DEVICE_TABLE(spi, cc2520_ids);
> +
> +static const struct of_device_id cc2520_of_ids[] = {
> +	{.compatible = "ti,cc2520", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, cc2520_of_ids);
> +
> +/*SPI Driver Structure*/
> +static struct spi_driver cc2520_driver = {
> +	.driver = {
> +		.name = "cc2520",
> +		.bus = &spi_bus_type,
> +		.owner = THIS_MODULE,
> +		.of_match_table = of_match_ptr(cc2520_of_ids),
> +	},
> +	.id_table = cc2520_ids,
> +	.probe = cc2520_probe,
> +	.remove = cc2520_remove,
> +};
> +module_spi_driver(cc2520_driver);
> +
> +MODULE_DESCRIPTION("CC2520 Transceiver Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/spi/cc2520.h b/include/linux/spi/cc2520.h
> new file mode 100644
> index 0000000..68a2c88
> --- /dev/null
> +++ b/include/linux/spi/cc2520.h

In this location of header files are platform_data structs only. I think
you should leave the cc2520_platform_data in this file and move the rest
of declaration to you cc2520.c file.

> @@ -0,0 +1,176 @@
> +#ifndef __CC2520_H
> +#define __CC2520_H
> +
> +#define RSSI_VALID		0
> +#define RSSI_OFFSET		78
> +#define CC2520_FREG_MASK	0x3F
> +
> +struct cc2520_platform_data {
> +	int fifo;
> +	int fifop;
> +	int cca;
> +	int sfd;
> +	int reset;
> +	int vreg;
> +};
> +

- Alex

Re: [Linux-zigbee-devel] [PATCH net-next 1/3] ieee802154: cc2520: driver for TI cc2520 radio

[Varka Bhadram]

Hi Alex,

Thanks for the comments.

I will create a patch for the required changes with Reported-by 
Alexander Aring  <...> reply if this is okay for you.


On 06/16/2014 01:08 PM, Alexander Aring wrote:
> Hi Varka,
>
> On Mon, Jun 16, 2014 at 10:21:56AM +0530, Varka Bhadram wrote:
> Maybe some more information about this chip in the commit msg?
I will provide the proper commit messages in next version
>
> +/*Generic Functions*/
> +static int cc2520_cmd_strobe(struct cc2520_private *priv,
> +						u8 cmd)
> +{
> +	int ret;
> +	u8 status = 0xff;
> +	struct spi_message msg;
> +	struct spi_transfer xfer = {
> +		.len = 0,
> +		.tx_buf = priv->buf,
> +		.rx_buf = priv->buf,
> +	};
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfer, &msg);
> I see, you maybe looked at others drivers like at86rf230 and see what
> they do there. I really don't like the lowlevel spi calls in the others
> drivers. There are spi helper functions like 'spi_write_then_read' look
> in drivers/spi/spi.c for the helper functions. Then you don't need the
> buffer_mutex also.
In at86rf230 driver first it hold the mutex lock for buffer then 
__at86rf230_read_subreg()/ __at86rf230_write()
functions called. One more thing is that at the low level spi core is 
holding the lock for the buffer data.
We can remove the buffer mutex.
>> +
>> +	mutex_lock(&priv->buffer_mutex);
>> +	priv->buf[xfer.len++] = cmd;
>> +	dev_vdbg(&priv->spi->dev,
>> +			"command strobe buf[0] = %02x\n",
>> +			priv->buf[0]);
>> +
>> +	ret = spi_sync(priv->spi, &msg);
>> +	if (!ret)
>> +		status = priv->buf[0];
>> +	dev_vdbg(&priv->spi->dev,
>> +			"buf[0] = %02x\n", priv->buf[0]);
>> +	mutex_unlock(&priv->buffer_mutex);
>> +
>> +	return ret;
>> +}
>> +
> ....
>
>> +
>> +static void cc2520_unregister(struct cc2520_private *priv)
>> +{
>> +	ieee802154_unregister_device(priv->dev);
>> +	ieee802154_free_device(priv->dev);
>> +}
> Only used in remove callback of module. It's small enough to do this in
> the remove callback.
>
Ya its nice . We can save the cpu context switching time also....
>> +
>> +static void cc2520_fifop_irqwork(struct work_struct *work)
>> +{
>> +	struct cc2520_private *priv
>> +		= container_of(work, struct cc2520_private, fifop_irqwork);
>> +
>> +	dev_dbg(&priv->spi->dev, "fifop interrupt received\n");
>> +
>> +	if (gpio_get_value(priv->fifo_pin))
>> +		cc2520_rx(priv);
>> +	else
>> +		dev_err(&priv->spi->dev, "rxfifo overflow\n");
>> +
>> +	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
>> +	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
>> +}
>> +
>> +static irqreturn_t cc2520_fifop_isr(int irq, void *data)
>> +{
>> +	struct cc2520_private *priv = data;
>> +
>> +	schedule_work(&priv->fifop_irqwork);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t cc2520_sfd_isr(int irq, void *data)
>> +{
>> +	struct cc2520_private *priv = data;
>> +
>> +	spin_lock(&priv->lock);
> You need to use here spin_lock_irqsave and spin_unlock_irqrestore here.
> Please verify you locking with PROVE_LOCKING enabled in your kernel.
>
> In your xmit callback you use a irqsave spinlocks there. You need always
> save to the "strongest" context which is a interrupt in your case.
This type of mechanism is needed when you want to remember the interrupt 
status for the
IRQ/system.
>> +	if (priv->is_tx) {
>> +		dev_dbg(&priv->spi->dev, "SFD for TX\n");
>> +		priv->is_tx = 0;
>> +		complete(&priv->tx_complete);
>> +	} else
>> +		dev_dbg(&priv->spi->dev, "SFD for RX\n");
> make brackets in the else branch if you have brackets in the "if" branch.
>
> You don't need to lock all the things here I think:
>
> --snip
> 	spin_lock_irqsave(&priv->lock, flags);
> 	if (priv->is_tx) {
> 		priv->is_tx = 0;
> 		spin_unlock_irqrestore(&priv->lock, flags);
> 		dev_dbg(&priv->spi->dev, "SFD for TX\n");
> 		complete(&priv->tx_complete);
> 	} else {
> 		spin_unlock_irqrestore(&priv->lock, flags);
> 		dev_dbg(&priv->spi->dev, "SFD for RX\n");
> 	}
> --snap
>
Ya this can be the good approach...
>> +	spin_unlock(&priv->lock);
>> +
>> +	return IRQ_HANDLED
>> +/*Driver probe function*/
>> +static int cc2520_probe(struct spi_device *spi)
>> +{
>> +	struct cc2520_private *priv;
>> +	struct pinctrl *pinctrl;
>> +	struct cc2520_platform_data *pdata;
>> +	struct device_node __maybe_unused *np = spi->dev.of_node;
>> +	int ret;
>> +
>> +	priv = kzalloc(sizeof(struct cc2520_private), GFP_KERNEL);
>> +	if (!priv) {
>> +		ret = -ENOMEM;
>> +		goto err_free_local;
>> +	}
> why not devm_ calls?
I will surely change it to devm_....
>> +
>> +	spi_set_drvdata(spi, priv);
>> +
>> +	pinctrl = devm_pinctrl_get_select_default(&spi->dev);
>> +
>> +	if (gpio_is_valid(pdata->vreg)) {
>> +		ret = devm_gpio_request_one(&spi->dev, pdata->vreg,
>> +					GPIOF_OUT_INIT_LOW, "vreg");
>> +		if (ret)
>> +			goto err_hw_init;
>> +	}
> You should check on the not optional pins if you can request them. You
> use in the above code the pins vreg, reset, fifo_irq, sfd. And this
> failed if the gpio's are not valid.
>
> means:
>
> if (!gpio_is_valid(pdata->vreg)) {
> 	dev_err(....)
> 	ret = -EINVAL;
> 	goto ...;
> }
>
> on all pins which are needed to use your chip.
>
>> +
>> +	gpio_set_value(pdata->vreg, HIGH);
>> +	udelay(100);
>> +
>> +	gpio_set_value(pdata->reset, HIGH);
>> +	udelay(200);
>> +
>> +	ret = cc2520_hw_init(priv);
>> +	if (ret)
>> +		goto err_hw_init;
>> +
>> +	/*Set up fifop interrupt */
>> +	priv->fifo_irq = gpio_to_irq(pdata->fifop);
> why is fifo_irq in your "private data"? This is only used in this function.

Ya this is my mistake. Previously i used in other place also.

>> +	ret = devm_request_irq(&spi->dev,
>> +				priv->fifo_irq,
>> +				cc2520_fifop_isr,
>> +				IRQF_TRIGGER_RISING,
>> +				dev_name(&spi->dev),
>> +				priv);
>> +	if (ret) {
>> +		dev_err(&spi->dev, "could not get fifop irq\n");
>> +		goto err_hw_init;
>> +	}
>> +
>> +	/*Set up sfd interrupt*/
>> +	ret = devm_request_irq(&spi->dev,
>> +				gpio_to_irq(pdata->sfd),
>> +				cc2520_sfd_isr,
>> +				IRQF_TRIGGER_FALLING,
>> +				dev_name(&spi->dev),
>> +				priv);
>> +	if (ret) {
>> +		dev_err(&spi->dev, "could not get sfd irq\n");
>> +		goto err_hw_init;
>> +	}
>> +
>> +	ret = cc2520_register(priv);
>> +	if (ret)
>> +		goto err_hw_init;
>> +
>> +	return 0;
>> +
>> +err_hw_init:
>> +	mutex_destroy(&priv->buffer_mutex);
>> +	flush_work(&priv->fifop_irqwork);
>> +
>> +err_free_buf:
>> +	kfree(priv->buf);
>> +
>> +err_free_local:
>> +	kfree(priv);
>> +
>> +	return ret;
>> +}
>> +
>> +/*Driver remove function*/
>> +static int cc2520_remove(struct spi_device *spi)
>> +{
>> +	struct cc2520_private *priv = spi_get_drvdata(spi);
>> +
>> +	cc2520_unregister(priv);
>> +
>> +	mutex_destroy(&priv->buffer_mutex);
>> +	flush_work(&priv->fifop_irqwork);
>> +
>> +	kfree(priv->buf);
>> +	kfree(priv);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct spi_device_id cc2520_ids[] = {
>> +	{"cc2520", 0},
> You don't need to set the driver_data to 0. Simple:
> 	{ "cc2520", },
this does not make any difference.
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(spi, cc2520_ids);
>> +
>> +static const struct of_device_id cc2520_of_ids[] = {
>> +	{.compatible = "ti,cc2520", },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, cc2520_of_ids);
>> +
>> +/*SPI Driver Structure*/
>> +static struct spi_driver cc2520_driver = {
>> +	.driver = {
>> +		.name = "cc2520",
>> +		.bus = &spi_bus_type,
>> +		.owner = THIS_MODULE,
>> +		.of_match_table = of_match_ptr(cc2520_of_ids),
>> +	},
>> +	.id_table = cc2520_ids,
>> +	.probe = cc2520_probe,
>> +	.remove = cc2520_remove,
>> +};
>> +module_spi_driver(cc2520_driver);
>> +
>> +MODULE_DESCRIPTION("CC2520 Transceiver Driver");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/include/linux/spi/cc2520.h b/include/linux/spi/cc2520.h
>> new file mode 100644
>> index 0000000..68a2c88
>> --- /dev/null
>> +++ b/include/linux/spi/cc2520.h
> In this location of header files are platform_data structs only. I think
> you should leave the cc2520_platform_data in this file and move the rest
> of declaration to you cc2520.c file.
>
I will move the code
>> @@ -0,0 +1,176 @@
>> +#ifndef __CC2520_H
>> +#define __CC2520_H
>> +
>> +#define RSSI_VALID		0
>> +#define RSSI_OFFSET		78
>> +#define CC2520_FREG_MASK	0x3F
>> +
>> +struct cc2520_platform_data {
>> +	int fifo;
>> +	int fifop;
>> +	int cca;
>> +	int sfd;
>> +	int reset;
>> +	int vreg;
>> +};
>> +
> - Alex


-Varka Bhadram

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Re: [Linux-zigbee-devel] [PATCH net-next 1/3] ieee802154: cc2520: driver for TI cc2520 radio

[Alexander Aring]

Hi,

On Mon, Jun 16, 2014 at 02:21:19PM +0530, Varka Bhadram wrote:
...
> >>+
> >>+static void cc2520_unregister(struct cc2520_private *priv)
> >>+{
> >>+	ieee802154_unregister_device(priv->dev);
> >>+	ieee802154_free_device(priv->dev);
> >>+}
> >Only used in remove callback of module. It's small enough to do this in
> >the remove callback.
> >

There is no context switch here. It's a little bit faster because you
don't put some things on the stack. Alternative would be to add a inline
keyword to this function.

> Ya its nice . We can save the cpu context switching time also....
> >>+
> >>+static void cc2520_fifop_irqwork(struct work_struct *work)
> >>+{
> >>+	struct cc2520_private *priv
> >>+		= container_of(work, struct cc2520_private, fifop_irqwork);
> >>+
> >>+	dev_dbg(&priv->spi->dev, "fifop interrupt received\n");
> >>+
> >>+	if (gpio_get_value(priv->fifo_pin))
> >>+		cc2520_rx(priv);
> >>+	else
> >>+		dev_err(&priv->spi->dev, "rxfifo overflow\n");
> >>+
> >>+	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
> >>+	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
> >>+}
> >>+
> >>+static irqreturn_t cc2520_fifop_isr(int irq, void *data)
> >>+{
> >>+	struct cc2520_private *priv = data;
> >>+
> >>+	schedule_work(&priv->fifop_irqwork);
> >>+
> >>+	return IRQ_HANDLED;
> >>+}
> >>+
> >>+static irqreturn_t cc2520_sfd_isr(int irq, void *data)
> >>+{
> >>+	struct cc2520_private *priv = data;
> >>+
> >>+	spin_lock(&priv->lock);
> >You need to use here spin_lock_irqsave and spin_unlock_irqrestore here.
> >Please verify you locking with PROVE_LOCKING enabled in your kernel.
> >
> >In your xmit callback you use a irqsave spinlocks there. You need always
> >save to the "strongest" context which is a interrupt in your case.
> This type of mechanism is needed when you want to remember the interrupt
> status for the
> IRQ/system.

Yes you need I spinlock here, but spin_lock isn't irqsave but you need a
spin_lock function which is irqsave. This is
spin_lock_irqsave/spin_unlock_irqrestore.

You use these function in xmit callback for locking and that makes no
sense. You need to use spin_lock_irqsave/spin_unlock_irqrestore there of
course. But using in one function
spin_lock_irqsave/spin_unlock_irqrestore and in the other function
spin_lock/spin_unlock for the same spinlock is wrong.
In your case the strongest context is an irq, so you need for your
locking irqsave functions.

Please compile your kernel with PROVE_LOCKING and test your driver, then
you will see some warnings about deadlocks.

> >>+	if (priv->is_tx) {
> >>+		dev_dbg(&priv->spi->dev, "SFD for TX\n");
> >>+		priv->is_tx = 0;
> >>+		complete(&priv->tx_complete);
> >>+	} else
> >>+		dev_dbg(&priv->spi->dev, "SFD for RX\n");
> >make brackets in the else branch if you have brackets in the "if" branch.
> >
> >You don't need to lock all the things here I think:
> >
> >--snip
> >	spin_lock_irqsave(&priv->lock, flags);
> >	if (priv->is_tx) {
> >		priv->is_tx = 0;
> >		spin_unlock_irqrestore(&priv->lock, flags);
> >		dev_dbg(&priv->spi->dev, "SFD for TX\n");
> >		complete(&priv->tx_complete);
> >	} else {
> >		spin_unlock_irqrestore(&priv->lock, flags);
> >		dev_dbg(&priv->spi->dev, "SFD for RX\n");
> >	}
> >--snap
> >
> Ya this can be the good approach...
> >>+	spin_unlock(&priv->lock);
> >>+
> >>+	return IRQ_HANDLED
> >>+/*Driver probe function*/
> >>+static int cc2520_probe(struct spi_device *spi)
> >>+{
> >>+	struct cc2520_private *priv;
> >>+	struct pinctrl *pinctrl;
> >>+	struct cc2520_platform_data *pdata;
> >>+	struct device_node __maybe_unused *np = spi->dev.of_node;
> >>+	int ret;
> >>+
> >>+	priv = kzalloc(sizeof(struct cc2520_private), GFP_KERNEL);
> >>+	if (!priv) {
> >>+		ret = -ENOMEM;
> >>+		goto err_free_local;
> >>+	}
> >why not devm_ calls?
> I will surely change it to devm_....
> >>+
> >>+	spi_set_drvdata(spi, priv);
> >>+
> >>+	pinctrl = devm_pinctrl_get_select_default(&spi->dev);
> >>+
> >>+	if (gpio_is_valid(pdata->vreg)) {
> >>+		ret = devm_gpio_request_one(&spi->dev, pdata->vreg,
> >>+					GPIOF_OUT_INIT_LOW, "vreg");
> >>+		if (ret)
> >>+			goto err_hw_init;
> >>+	}
> >You should check on the not optional pins if you can request them. You
> >use in the above code the pins vreg, reset, fifo_irq, sfd. And this

s/above/below

> >failed if the gpio's are not valid.
> >
> >means:
> >
> >if (!gpio_is_valid(pdata->vreg)) {
> >	dev_err(....)
> >	ret = -EINVAL;
> >	goto ...;
> >}
> >
> >on all pins which are needed to use your chip.
> >
> >>+
> >>+	gpio_set_value(pdata->vreg, HIGH);
> >>+	udelay(100);
> >>+
> >>+	gpio_set_value(pdata->reset, HIGH);
> >>+	udelay(200);
> >>+
> >>+	ret = cc2520_hw_init(priv);
> >>+	if (ret)
> >>+		goto err_hw_init;
> >>+
> >>+	/*Set up fifop interrupt */
> >>+	priv->fifo_irq = gpio_to_irq(pdata->fifop);
...
> >>+static const struct spi_device_id cc2520_ids[] = {
> >>+	{"cc2520", 0},
> >You don't need to set the driver_data to 0. Simple:
> >	{ "cc2520", },
> this does not make any difference.

Yes, but saves code. :-)

Usual prefer coding is:

"(no difference + more code) < (no difference + less code)"

- Alex

[PATCH net-next 2/3] ieee802154: cc2520: add driver to kernel build system

[Varka Bhadram]

Signed-off-by: Varka Bhadram <varkab@cdac.in>
---
 drivers/net/ieee802154/Kconfig  |   11 +++++++++++
 drivers/net/ieee802154/Makefile |    1 +
 2 files changed, 12 insertions(+)

diff --git a/drivers/net/ieee802154/Kconfig b/drivers/net/ieee802154/Kconfig
index 3e89bea..680422f 100644
--- a/drivers/net/ieee802154/Kconfig
+++ b/drivers/net/ieee802154/Kconfig
@@ -51,3 +51,14 @@ config IEEE802154_MRF24J40
 
 	  This driver can also be built as a module. To do so, say M here.
 	  the module will be called 'mrf24j40'.
+
+config IEEE802154_CC2520
+	depends on IEEE802154_DRIVERS && MAC802154
+	tristate "cc2520 transceiver driver"
+	depends on SPI
+	---help---
+	  Say Y here to enable the CC2520 SPI 802.15.4 wireless
+	  controller.
+
+	  This driver can also be built as a module. To do so, say M here.
+	  the module will be called 'cc2520'.
diff --git a/drivers/net/ieee802154/Makefile b/drivers/net/ieee802154/Makefile
index abb0c08..655cb95 100644
--- a/drivers/net/ieee802154/Makefile
+++ b/drivers/net/ieee802154/Makefile
@@ -2,3 +2,4 @@ obj-$(CONFIG_IEEE802154_FAKEHARD) += fakehard.o
 obj-$(CONFIG_IEEE802154_FAKELB) += fakelb.o
 obj-$(CONFIG_IEEE802154_AT86RF230) += at86rf230.o
 obj-$(CONFIG_IEEE802154_MRF24J40) += mrf24j40.o
+obj-$(CONFIG_IEEE802154_CC2520) += cc2520.o
-- 
1.7.9.5

[PATCH net-next 3/3] devicetree: add devicetree bindings for cc2520 driver

[Varka Bhadram]

Signed-off-by: Varka Bhadram <varkab@cdac.in>
---
 .../devicetree/bindings/net/ieee802154/cc2520.txt  |   26 ++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ieee802154/cc2520.txt

diff --git a/Documentation/devicetree/bindings/net/ieee802154/cc2520.txt b/Documentation/devicetree/bindings/net/ieee802154/cc2520.txt
new file mode 100644
index 0000000..f0a749d
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/ieee802154/cc2520.txt
@@ -0,0 +1,26 @@
+CC2520 IEEE 802.15.4 Compatible Radio
+
+Required properties:
+	- compatible:		should be "ti,cc2520"
+	- spi-max-frequency:	maximal bus speed (8000000), should be set to 4000000 depends
+				sync or async operation mode
+	- reg:			the chipselect index
+	- mode:			SPI mode
+Example:
+
+	cc2520@0 {
+		compatible = "ti,cc2520";
+		reg = <0>;
+		spi-max-frequency = <4000000>;
+		mode = <1>;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&cc2520_cape_pins>;	/*GPIO pin muxing details*/
+
+		fifo-gpio = <&gpio1 18 0>;
+		fifop-gpio = <&gpio1 19 0>;
+		sfd-gpio = <&gpio1 13 0>;
+		cca-gpio = <&gpio1 16 0>;
+		vreg-gpio = <&gpio0 31 0>;
+		reset-gpio = <&gpio1 12 0>;
+	};
-- 
1.7.9.5