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

From: pavan_savoy
Date: Fri Feb 04 2011 - 03:24:10 EST

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 and document it in Documentation/ABI/testing/
under sysfs-platform-kim.

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>
---
Documentation/ABI/testing/sysfs-platform-kim | 48 +++++
drivers/misc/ti-st/st_kim.c | 244 +++++++++++++-------------
include/linux/ti_wilink_st.h | 19 ++-
3 files changed, 186 insertions(+), 125 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-platform-kim

diff --git a/Documentation/ABI/testing/sysfs-platform-kim b/Documentation/ABI/testing/sysfs-platform-kim
new file mode 100644
index 0000000..c165327
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-kim
@@ -0,0 +1,48 @@
+What: /sys/devices/platform/kim/dev_name
+Date: January 2010
+KernelVersion: 2.6.38
+Contact: "Pavan Savoy" <pavan_savoy@xxxxxx>
+Description:
+ Name of the UART device at which the WL128x chip
+ is connected. example: "/dev/ttyS0".
+ The device name flows down to architecture specific board
+ initialization file from the SFI/ATAGS bootloader
+ firmware. The name exposed is read from the user-space
+ dameon and opens the device when install is requested.
+
+What: /sys/devices/platform/kim/baud_rate
+Date: January 2010
+KernelVersion: 2.6.38
+Contact: "Pavan Savoy" <pavan_savoy@xxxxxx>
+Description:
+ The maximum reliable baud-rate the host can support.
+ Different platforms tend to have different high-speed
+ UART configurations, so the baud-rate needs to be set
+ locally and also sent across to the WL128x via a HCI-VS
+ command. The entry is read and made use by the user-space
+ daemon when the ldisc install is requested.
+
+What: /sys/devices/platform/kim/flow_cntrl
+Date: January 2010
+KernelVersion: 2.6.38
+Contact: "Pavan Savoy" <pavan_savoy@xxxxxx>
+Description:
+ The WL128x makes use of flow control mechanism, and this
+ entry most often should be 1, the host's UART is required
+ to have the capability of flow-control, or else this
+ entry can be made use of for exceptions.
+
+What: /sys/devices/platform/kim/install
+Date: January 2010
+KernelVersion: 2.6.38
+Contact: "Pavan Savoy" <pavan_savoy@xxxxxx>
+Description:
+ When one of the protocols Bluetooth, FM or GPS wants to make
+ use of the shared UART transport, it registers to the shared
+ transport driver, which will signal the user-space for opening,
+ configuring baud and install line discipline via this sysfs
+ entry. This entry would be polled upon by the user-space
+ daemon managing the UART, and is notified about the change
+ by the sysfs_notify. The value would be '1' when UART needs
+ to be opened/ldisc installed, and would be '0' when UART
+ is no more required and needs to be closed.
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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