1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/modem/m6718_spi/modem_driver.c b/drivers/modem/m6718_spi/modem_driver.c
new file mode 100644
index 00000000000..8086e97aa7c
--- /dev/null
+++ b/drivers/modem/m6718_spi/modem_driver.c
@@ -0,0 +1,292 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ *
+ * Author: Chris Blair <chris.blair@stericsson.com> for ST-Ericsson
+ *   based on modem_shrm_driver.c
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * SPI driver implementing the M6718 inter-processor communication protocol.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/modem/modem_client.h>
+#include <linux/modem/m6718_spi/modem_driver.h>
+#include <linux/modem/m6718_spi/modem_net.h>
+#include <linux/modem/m6718_spi/modem_char.h>
+#include "modem_protocol.h"
+
+#ifdef CONFIG_PHONET
+static void phonet_rcv_tasklet_func(unsigned long);
+static struct tasklet_struct phonet_rcv_tasklet;
+#endif
+
+static struct modem_spi_dev modem_driver_data = {
+	.dev = NULL,
+	.ndev = NULL,
+	.modem = NULL,
+	.isa_context = NULL,
+	.netdev_flag_up = 0
+};
+
+/**
+ * modem_m6718_spi_receive() - Receive a frame from L1 physical layer
+ * @sdev:	pointer to spi device structure
+ * @channel:	L2 mux channel id
+ * @len:	frame data length
+ * @data:	pointer to frame data
+ *
+ * This function is called from the driver L1 physical transport layer. It
+ * copies the frame data to the receive queue for the channel on which the data
+ * was received.
+ *
+ * Special handling is given to slave-loopback channels where the data is simply
+ * sent back to the modem on the same channel.
+ *
+ * Special handling is given to the ISI channel when PHONET is enabled - the
+ * phonet tasklet is scheduled in order to pump the received data through the
+ * net device interface.
+ */
+int modem_m6718_spi_receive(struct spi_device *sdev, u8 channel,
+	u32 len, void *data)
+{
+	u32 size = 0;
+	int ret = 0;
+	int idx;
+	u8 *psrc;
+	u32 writeptr;
+	struct message_queue *q;
+	struct isa_device_context *isadev;
+
+	dev_dbg(&sdev->dev, "L2 received frame from L1: channel %d len %d\n",
+		channel, len);
+
+#ifdef CONFIG_MODEM_M6718_SPI_ENABLE_FEATURE_LOOPBACK
+	if (channel == MODEM_M6718_SPI_CHN_SLAVE_LOOPBACK0 ||
+		channel == MODEM_M6718_SPI_CHN_SLAVE_LOOPBACK1) {
+		/* data received on slave loopback channel - loop it back */
+		modem_m6718_spi_send(&modem_driver_data, channel, len, data);
+		return 0;
+	}
+#endif
+
+	/* find the isa device index for this L2 channel */
+	idx = modem_get_cdev_index(channel);
+	if (idx < 0) {
+		dev_err(&sdev->dev, "failed to get isa device index\n");
+		return idx;
+	}
+	isadev = &modem_driver_data.isa_context->isadev[idx];
+	q = &isadev->dl_queue;
+
+	spin_lock(&q->update_lock);
+
+	/* verify message can be contained in buffer */
+	writeptr = q->writeptr;
+	ret = modem_isa_queue_msg(q, len);
+	if (ret >= 0) {
+		/* memcopy RX data */
+		if ((writeptr + len) >= q->size) {
+			psrc = (u8 *)data;
+			size = q->size - writeptr;
+			/* copy first part of msg */
+			memcpy((q->fifo_base + writeptr), psrc, size);
+			psrc += size;
+			/* copy second part of msg at the top of fifo */
+			memcpy(q->fifo_base, psrc, (len - size));
+		} else {
+			memcpy((q->fifo_base + writeptr), data, len);
+		}
+	}
+	spin_unlock(&q->update_lock);
+
+	if (ret < 0) {
+		dev_err(&sdev->dev, "failed to queue frame!");
+		return ret;
+	}
+
+#ifdef CONFIG_PHONET
+	if (channel == MODEM_M6718_SPI_CHN_ISI &&
+		modem_driver_data.netdev_flag_up)
+		tasklet_schedule(&phonet_rcv_tasklet);
+#endif
+	return ret;
+}
+EXPORT_SYMBOL_GPL(modem_m6718_spi_receive);
+
+static void phonet_rcv_tasklet_func(unsigned long unused)
+{
+	ssize_t result;
+
+	dev_dbg(modem_driver_data.dev, "receiving frames for phonet\n");
+	/* continue receiving while there are frames in the queue */
+	for (;;) {
+		result = modem_net_receive(modem_driver_data.ndev);
+		if (result == 0) {
+			dev_dbg(modem_driver_data.dev,
+				"queue is empty, finished receiving\n");
+			break;
+		}
+		if (result < 0) {
+			dev_err(modem_driver_data.dev,
+				"failed to receive frame from queue!\n");
+			break;
+		}
+	}
+}
+
+static int spi_probe(struct spi_device *sdev)
+{
+	int result = 0;
+
+	spi_set_drvdata(sdev, &modem_driver_data);
+
+	if (modem_protocol_probe(sdev) != 0) {
+		dev_err(&sdev->dev,
+			"failed to initialise link protocol\n");
+		result = -ENODEV;
+		goto rollback;
+	}
+
+	/*
+	 * Since we can have multiple spi links for the same modem, only
+	 * initialise the modem data and char/net interfaces once.
+	 */
+	if (modem_driver_data.dev == NULL) {
+		modem_driver_data.dev = &sdev->dev;
+		modem_driver_data.modem =
+			modem_get(modem_driver_data.dev, "m6718");
+		if (modem_driver_data.modem == NULL) {
+			dev_err(&sdev->dev,
+				"failed to retrieve modem description\n");
+			result = -ENODEV;
+			goto rollback_protocol_init;
+		}
+
+		result = modem_isa_init(&modem_driver_data);
+		if (result < 0) {
+			dev_err(&sdev->dev,
+				"failed to initialise char interface\n");
+			goto rollback_modem_get;
+		}
+
+		result = modem_net_init(&modem_driver_data);
+		if (result < 0) {
+			dev_err(&sdev->dev,
+				"failed to initialse net interface\n");
+			goto rollback_isa_init;
+		}
+
+#ifdef CONFIG_PHONET
+		tasklet_init(&phonet_rcv_tasklet, phonet_rcv_tasklet_func, 0);
+#endif
+	}
+	return result;
+
+rollback_isa_init:
+	modem_isa_exit(&modem_driver_data);
+rollback_modem_get:
+	modem_put(modem_driver_data.modem);
+rollback_protocol_init:
+	modem_protocol_exit();
+rollback:
+	return result;
+}
+
+static int __exit spi_remove(struct spi_device *sdev)
+{
+	modem_protocol_exit();
+	modem_net_exit(&modem_driver_data);
+	modem_isa_exit(&modem_driver_data);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+/**
+ * spi_suspend() - This routine puts the IPC driver in to suspend state.
+ * @sdev: pointer to spi device structure.
+ * @mesg: pm operation
+ *
+ * This routine checks the current ongoing communication with modem
+ * and prevents suspend if modem communication is on-going.
+ */
+static int spi_suspend(struct spi_device *sdev, pm_message_t mesg)
+{
+	bool busy;
+	int ret = -EBUSY;
+
+	dev_dbg(&sdev->dev, "suspend called\n");
+	busy = modem_protocol_is_busy(sdev);
+	if (busy) {
+		dev_warn(&sdev->dev, "suspend failed (protocol busy)\n");
+		return -EBUSY;
+	}
+	ret = modem_protocol_suspend(sdev);
+	if (ret) {
+		dev_warn(&sdev->dev, "suspend failed, (protocol suspend))\n");
+		return ret;
+	}
+	ret = modem_net_suspend(modem_driver_data.ndev);
+	if (ret) {
+		dev_warn(&sdev->dev, "suspend failed, (netdev suspend)\n");
+		return ret;
+	}
+	return 0;
+}
+
+/**
+ * spi_resume() - This routine resumes the IPC driver from suspend state.
+ * @sdev: pointer to spi device structure
+ */
+static int spi_resume(struct spi_device *sdev)
+{
+	int ret;
+
+	dev_dbg(&sdev->dev, "resume called\n");
+	ret = modem_protocol_resume(sdev);
+	if (ret) {
+		dev_warn(&sdev->dev, "resume failed, (protocol resume))\n");
+		return ret;
+	}
+	ret = modem_net_resume(modem_driver_data.ndev);
+	if (ret) {
+		dev_warn(&sdev->dev, "resume failed, (netdev resume))\n");
+		return ret;
+	}
+	return 0;
+}
+#endif /* CONFIG_PM */
+
+static struct spi_driver spi_driver = {
+	.driver = {
+		.name = "spimodem",
+		.bus  = &spi_bus_type,
+		.owner = THIS_MODULE
+	},
+	.probe = spi_probe,
+	.remove = __exit_p(spi_remove),
+#ifdef CONFIG_PM
+	.suspend = spi_suspend,
+	.resume = spi_resume,
+#endif
+};
+
+static int __init m6718_spi_driver_init(void)
+{
+	pr_info("M6718 modem driver initialising\n");
+	modem_protocol_init();
+	return spi_register_driver(&spi_driver);
+}
+module_init(m6718_spi_driver_init);
+
+static void __exit m6718_spi_driver_exit(void)
+{
+	pr_debug("M6718 modem SPI IPC driver exit\n");
+	spi_unregister_driver(&spi_driver);
+}
+module_exit(m6718_spi_driver_exit);
+
+MODULE_AUTHOR("Chris Blair <chris.blair@stericsson.com>");
+MODULE_DESCRIPTION("M6718 modem IPC SPI driver");
+MODULE_LICENSE("GPL v2");