[PATCH 2/7] drivers:misc: ti-st: move from rfkill to sysfs

[pavan_savoy]

From: Pavan Savoy <pavan_savoy@xxxxxx>

The communication between ST KIM and UIM was interfaced
over the /dev/rfkill device node.
Move the interface to a simpler less abusive sysfs entry
mechanism.

Shared transport driver would now read the UART details
originally received by bootloader or firmware as platform
data.
The data read will be shared over sysfs entries for the user-space
UIM or other n/w manager/plugins to be read, and assist the driver
by opening up the UART, setting the baud-rate and installing the
line discipline.

Signed-off-by: Pavan Savoy <pavan_savoy@xxxxxx>
---
 drivers/misc/ti-st/st_kim.c  |  244 +++++++++++++++++++++---------------------
 include/linux/ti_wilink_st.h |   19 +++-
 2 files changed, 138 insertions(+), 125 deletions(-)

diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index 707c858..a7fda81 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -30,46 +30,12 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/sched.h>
-#include <linux/rfkill.h>
+#include <linux/tty.h>
 
 #include <linux/skbuff.h>
 #include <linux/ti_wilink_st.h>
 
 
-static int kim_probe(struct platform_device *pdev);
-static int kim_remove(struct platform_device *pdev);
-
-/* KIM platform device driver structure */
-static struct platform_driver kim_platform_driver = {
-	.probe = kim_probe,
-	.remove = kim_remove,
-	/* TODO: ST driver power management during suspend/resume ?
-	 */
-#if 0
-	.suspend = kim_suspend,
-	.resume = kim_resume,
-#endif
-	.driver = {
-		   .name = "kim",
-		   .owner = THIS_MODULE,
-		   },
-};
-
-static int kim_toggle_radio(void*, bool);
-static const struct rfkill_ops kim_rfkill_ops = {
-	.set_block = kim_toggle_radio,
-};
-
-/* strings to be used for rfkill entries and by
- * ST Core to be used for sysfs debug entry
- */
-#define PROTO_ENTRY(type, name)	name
-const unsigned char *protocol_names[] = {
-	PROTO_ENTRY(ST_BT, "Bluetooth"),
-	PROTO_ENTRY(ST_FM, "FM"),
-	PROTO_ENTRY(ST_GPS, "GPS"),
-};
-
 #define MAX_ST_DEVICES	3	/* Imagine 1 on each UART for now */
 static struct platform_device *st_kim_devices[MAX_ST_DEVICES];
 
@@ -371,8 +337,7 @@ void st_kim_chip_toggle(enum proto_type type, enum kim_gpio_state state)
 	kim_gdata = dev_get_drvdata(&kim_pdev->dev);
 
 	if (kim_gdata->gpios[type] == -1) {
-		pr_info(" gpio not requested for protocol %s",
-			   protocol_names[type]);
+		pr_info("gpio not requested for protocol %d", type);
 		return;
 	}
 	switch (type) {
@@ -450,11 +415,6 @@ long st_kim_start(void *kim_data)
 	pr_info(" %s", __func__);
 
 	do {
-		/* TODO: this is only because rfkill sub-system
-		 * doesn't send events to user-space if the state
-		 * isn't changed
-		 */
-		rfkill_set_hw_state(kim_gdata->rfkill[ST_BT], 1);
 		/* Configure BT nShutdown to HIGH state */
 		gpio_set_value(kim_gdata->gpios[ST_BT], GPIO_LOW);
 		mdelay(5);	/* FIXME: a proper toggle */
@@ -462,22 +422,20 @@ long st_kim_start(void *kim_data)
 		mdelay(100);
 		/* re-initialize the completion */
 		INIT_COMPLETION(kim_gdata->ldisc_installed);
-#if 0 /* older way of signalling user-space UIM */
-		/* send signal to UIM */
-		err = kill_pid(find_get_pid(kim_gdata->uim_pid), SIGUSR2, 0);
-		if (err != 0) {
-			pr_info(" sending SIGUSR2 to uim failed %ld", err);
-			err = -1;
-			continue;
-		}
-#endif
-		/* unblock and send event to UIM via /dev/rfkill */
-		rfkill_set_hw_state(kim_gdata->rfkill[ST_BT], 0);
+		/* send notification to UIM */
+		kim_gdata->ldisc_install = 1;
+		pr_info("ldisc_install = 1");
+		sysfs_notify(&kim_gdata->kim_pdev->dev.kobj,
+				NULL, "install");
 		/* wait for ldisc to be installed */
 		err = wait_for_completion_timeout(&kim_gdata->ldisc_installed,
 				msecs_to_jiffies(LDISC_TIME));
 		if (!err) {	/* timeout */
 			pr_err("line disc installation timed out ");
+			kim_gdata->ldisc_install = 0;
+			pr_info("ldisc_install = 0");
+			sysfs_notify(&kim_gdata->kim_pdev->dev.kobj,
+					NULL, "install");
 			err = -1;
 			continue;
 		} else {
@@ -486,6 +444,10 @@ long st_kim_start(void *kim_data)
 			err = download_firmware(kim_gdata);
 			if (err != 0) {
 				pr_err("download firmware failed");
+				kim_gdata->ldisc_install = 0;
+				pr_info("ldisc_install = 0");
+				sysfs_notify(&kim_gdata->kim_pdev->dev.kobj,
+						NULL, "install");
 				continue;
 			} else {	/* on success don't retry */
 				break;
@@ -505,16 +467,15 @@ long st_kim_stop(void *kim_data)
 	struct kim_data_s	*kim_gdata = (struct kim_data_s *)kim_data;
 
 	INIT_COMPLETION(kim_gdata->ldisc_installed);
-#if 0 /* older way of signalling user-space UIM */
-	/* send signal to UIM */
-	err = kill_pid(find_get_pid(kim_gdata->uim_pid), SIGUSR2, 1);
-	if (err != 0) {
-		pr_err("sending SIGUSR2 to uim failed %ld", err);
-		return -1;
-	}
-#endif
-	/* set BT rfkill to be blocked */
-	err = rfkill_set_hw_state(kim_gdata->rfkill[ST_BT], 1);
+
+	/* Flush any pending characters in the driver and discipline. */
+	tty_ldisc_flush(kim_gdata->core_data->tty);
+	tty_driver_flush_buffer(kim_gdata->core_data->tty);
+
+	/* send uninstall notification to UIM */
+	pr_info("ldisc_install = 0");
+	kim_gdata->ldisc_install = 0;
+	sysfs_notify(&kim_gdata->kim_pdev->dev.kobj, NULL, "install");
 
 	/* wait for ldisc to be un-installed */
 	err = wait_for_completion_timeout(&kim_gdata->ldisc_installed,
@@ -553,33 +514,59 @@ static int show_list(struct seq_file *s, void *unused)
 	return 0;
 }
 
-/* function called from rfkill subsystem, when someone from
- * user space would write 0/1 on the sysfs entry
- * /sys/class/rfkill/rfkill0,1,3/state
- */
-static int kim_toggle_radio(void *data, bool blocked)
+static ssize_t show_install(struct device *dev,
+		struct device_attribute *attr, char *buf)
 {
-	enum proto_type type = *((enum proto_type *)data);
-	pr_debug(" %s: %d ", __func__, type);
+	struct kim_data_s *kim_data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", kim_data->ldisc_install);
+}
 
-	switch (type) {
-	case ST_BT:
-		/* do nothing */
-	break;
-	case ST_FM:
-	case ST_GPS:
-		if (blocked)
-			st_kim_chip_toggle(type, KIM_GPIO_INACTIVE);
-		else
-			st_kim_chip_toggle(type, KIM_GPIO_ACTIVE);
-	break;
-	case ST_MAX_CHANNELS:
-		pr_err(" wrong proto type ");
-	break;
-	}
-	return 0;
+static ssize_t show_dev_name(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct kim_data_s *kim_data = dev_get_drvdata(dev);
+	return sprintf(buf, "%s\n", kim_data->dev_name);
+}
+
+static ssize_t show_baud_rate(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct kim_data_s *kim_data = dev_get_drvdata(dev);
+	return sprintf(buf, "%ld\n", kim_data->baud_rate);
+}
+
+static ssize_t show_flow_cntrl(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct kim_data_s *kim_data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", kim_data->flow_cntrl);
 }
 
+/* structures specific for sysfs entries */
+static struct kobj_attribute ldisc_install =
+__ATTR(install, 0444, (void *)show_install, NULL);
+
+static struct kobj_attribute uart_dev_name =
+__ATTR(dev_name, 0444, (void *)show_dev_name, NULL);
+
+static struct kobj_attribute uart_baud_rate =
+__ATTR(baud_rate, 0444, (void *)show_baud_rate, NULL);
+
+static struct kobj_attribute uart_flow_cntrl =
+__ATTR(flow_cntrl, 0444, (void *)show_flow_cntrl, NULL);
+
+static struct attribute *uim_attrs[] = {
+	&ldisc_install.attr,
+	&uart_dev_name.attr,
+	&uart_baud_rate.attr,
+	&uart_flow_cntrl.attr,
+	NULL,
+};
+
+static struct attribute_group uim_attr_grp = {
+	.attrs = uim_attrs,
+};
+
 /**
  * st_kim_ref - reference the core's data
  *	This references the per-ST platform device in the arch/xx/
@@ -633,8 +620,9 @@ static int kim_probe(struct platform_device *pdev)
 {
 	long status;
 	long proto;
-	long *gpios = pdev->dev.platform_data;
 	struct kim_data_s	*kim_gdata;
+	struct ti_st_plat_data	*pdata = pdev->dev.platform_data;
+	long *gpios = pdata->gpios;
 
 	if ((pdev->id != -1) && (pdev->id < MAX_ST_DEVICES)) {
 		/* multiple devices could exist */
@@ -700,30 +688,18 @@ static int kim_probe(struct platform_device *pdev)
 	init_completion(&kim_gdata->kim_rcvd);
 	init_completion(&kim_gdata->ldisc_installed);
 
-	for (proto = 0; (proto < ST_MAX_CHANNELS)
-			&& (gpios[proto] != -1); proto++) {
-		/* TODO: should all types be rfkill_type_bt ? */
-		kim_gdata->rf_protos[proto] = proto;
-		kim_gdata->rfkill[proto] = rfkill_alloc(protocol_names[proto],
-			&pdev->dev, RFKILL_TYPE_BLUETOOTH,
-			&kim_rfkill_ops, &kim_gdata->rf_protos[proto]);
-		if (kim_gdata->rfkill[proto] == NULL) {
-			pr_err("cannot create rfkill entry for gpio %ld",
-				   gpios[proto]);
-			continue;
-		}
-		/* block upon creation */
-		rfkill_init_sw_state(kim_gdata->rfkill[proto], 1);
-		status = rfkill_register(kim_gdata->rfkill[proto]);
-		if (unlikely(status)) {
-			pr_err("rfkill registration failed for gpio %ld",
-				   gpios[proto]);
-			rfkill_unregister(kim_gdata->rfkill[proto]);
-			continue;
-		}
-		pr_info("rfkill entry created for %ld", gpios[proto]);
+	status = sysfs_create_group(&pdev->dev.kobj, &uim_attr_grp);
+	if (status) {
+		pr_err("failed to create sysfs entries");
+		return status;
 	}
 
+	/* copying platform data */
+	strncpy(kim_gdata->dev_name, pdata->dev_name, UART_DEV_NAME_LEN);
+	kim_gdata->flow_cntrl = pdata->flow_cntrl;
+	kim_gdata->baud_rate = pdata->baud_rate;
+	pr_info("sysfs entries created\n");
+
 	kim_debugfs_dir = debugfs_create_dir("ti-st", NULL);
 	if (IS_ERR(kim_debugfs_dir)) {
 		pr_err(" debugfs entries creation failed ");
@@ -741,9 +717,9 @@ static int kim_probe(struct platform_device *pdev)
 
 static int kim_remove(struct platform_device *pdev)
 {
-	/* free the GPIOs requested
-	 */
-	long *gpios = pdev->dev.platform_data;
+	/* free the GPIOs requested */
+	struct ti_st_plat_data	*pdata = pdev->dev.platform_data;
+	long *gpios = pdata->gpios;
 	long proto;
 	struct kim_data_s	*kim_gdata;
 
@@ -755,12 +731,11 @@ static int kim_remove(struct platform_device *pdev)
 		 * nShutdown gpio from the system
 		 */
 		gpio_free(gpios[proto]);
-		rfkill_unregister(kim_gdata->rfkill[proto]);
-		rfkill_destroy(kim_gdata->rfkill[proto]);
-		kim_gdata->rfkill[proto] = NULL;
 	}
 	pr_info("kim: GPIO Freed");
 	debugfs_remove_recursive(kim_debugfs_dir);
+
+	sysfs_remove_group(&pdev->dev.kobj, &uim_attr_grp);
 	kim_gdata->kim_pdev = NULL;
 	st_core_exit(kim_gdata->core_data);
 
@@ -769,23 +744,46 @@ static int kim_remove(struct platform_device *pdev)
 	return 0;
 }
 
+int kim_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct ti_st_plat_data	*pdata = pdev->dev.platform_data;
+
+	if (pdata->suspend)
+		return pdata->suspend(pdev, state);
+
+	return -EOPNOTSUPP;
+}
+
+int kim_resume(struct platform_device *pdev)
+{
+	struct ti_st_plat_data	*pdata = pdev->dev.platform_data;
+
+	if (pdata->resume)
+		return pdata->resume(pdev);
+
+	return -EOPNOTSUPP;
+}
+
 /**********************************************************************/
 /* entry point for ST KIM module, called in from ST Core */
+static struct platform_driver kim_platform_driver = {
+	.probe = kim_probe,
+	.remove = kim_remove,
+	.suspend = kim_suspend,
+	.resume = kim_resume,
+	.driver = {
+		.name = "kim",
+		.owner = THIS_MODULE,
+	},
+};
 
 static int __init st_kim_init(void)
 {
-	long ret = 0;
-	ret = platform_driver_register(&kim_platform_driver);
-	if (ret != 0) {
-		pr_err("platform drv registration failed");
-		return -1;
-	}
-	return 0;
+	return platform_driver_register(&kim_platform_driver);
 }
 
 static void __exit st_kim_deinit(void)
 {
-	/* the following returns void */
 	platform_driver_unregister(&kim_platform_driver);
 }
 
diff --git a/include/linux/ti_wilink_st.h b/include/linux/ti_wilink_st.h
index 1674ca7..010cda7 100644
--- a/include/linux/ti_wilink_st.h
+++ b/include/linux/ti_wilink_st.h
@@ -206,8 +206,8 @@ void gps_chrdrv_stub_init(void);
 /* time in msec to wait for
  * line discipline to be installed
  */
-#define LDISC_TIME	500
-#define CMD_RESP_TIME	500
+#define LDISC_TIME	1000
+#define CMD_RESP_TIME	800
 #define MAKEWORD(a, b)  ((unsigned short)(((unsigned char)(a)) \
 	| ((unsigned short)((unsigned char)(b))) << 8))
 
@@ -230,6 +230,7 @@ struct chip_version {
 	unsigned short maj_ver;
 };
 
+#define UART_DEV_NAME_LEN 32
 /**
  * struct kim_data_s - the KIM internal data, embedded as the
  *	platform's drv data. One for each ST device in the system.
@@ -271,6 +272,10 @@ struct kim_data_s {
 	enum proto_type rf_protos[ST_MAX_CHANNELS];
 	struct st_data_s *core_data;
 	struct chip_version version;
+	unsigned char ldisc_install;
+	unsigned char dev_name[UART_DEV_NAME_LEN];
+	unsigned char flow_cntrl;
+	unsigned long baud_rate;
 };
 
 /**
@@ -413,4 +418,14 @@ struct gps_event_hdr {
 	u16 plen;
 } __attribute__ ((packed));
 
+/* platform data */
+struct ti_st_plat_data {
+	long gpios[ST_MAX_CHANNELS]; /* BT, FM and GPS */
+	unsigned char dev_name[UART_DEV_NAME_LEN]; /* uart name */
+	unsigned char flow_cntrl; /* flow control flag */
+	unsigned long baud_rate;
+	int (*suspend)(struct platform_device *, pm_message_t);
+	int (*resume)(struct platform_device *);
+};
+
 #endif /* TI_WILINK_ST_H */
-- 
1.6.3.3

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