ath6kl: Implement support for power parameter control from userspace

In order to allow user space based control of power parameters, we use
available debugfs infrastructure. With these features user can control
power consumption by adjusting various sleep/wake up related parameters.
The feature has been added for testing purposes. All 5 parameters are
mandatory in correct order. They have to be written to the power_params
file. These are:

1) idle_period
2) no_of_pspoll
3) dtim_policy
4) tx_wakeup_policy
5) no_tx_to_wakeup

Example:

echo "200 1 0 1 1" > power_params
Signed-off-by: Rishi Panjwani <rpanjwan@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/debug.c

@@ -1567,6 +1567,66 @@ static const struct file_operations fops_listen_int = {
 	.llseek = default_llseek,
 };
 
+static ssize_t ath6kl_power_params_write(struct file *file,
+						const char __user *user_buf,
+						size_t count, loff_t *ppos)
+{
+	struct ath6kl *ar = file->private_data;
+	u8 buf[100];
+	unsigned int len = 0;
+	char *sptr, *token;
+	u16 idle_period, ps_poll_num, dtim,
+		tx_wakeup, num_tx;
+
+	len = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, user_buf, len))
+		return -EFAULT;
+	buf[len] = '\0';
+	sptr = buf;
+
+	token = strsep(&sptr, " ");
+	if (!token)
+		return -EINVAL;
+	if (kstrtou16(token, 0, &idle_period))
+		return -EINVAL;
+
+	token = strsep(&sptr, " ");
+	if (!token)
+		return -EINVAL;
+	if (kstrtou16(token, 0, &ps_poll_num))
+		return -EINVAL;
+
+	token = strsep(&sptr, " ");
+	if (!token)
+		return -EINVAL;
+	if (kstrtou16(token, 0, &dtim))
+		return -EINVAL;
+
+	token = strsep(&sptr, " ");
+	if (!token)
+		return -EINVAL;
+	if (kstrtou16(token, 0, &tx_wakeup))
+		return -EINVAL;
+
+	token = strsep(&sptr, " ");
+	if (!token)
+		return -EINVAL;
+	if (kstrtou16(token, 0, &num_tx))
+		return -EINVAL;
+
+	ath6kl_wmi_pmparams_cmd(ar->wmi, 0, idle_period, ps_poll_num,
+				dtim, tx_wakeup, num_tx, 0);
+
+	return count;
+}
+
+static const struct file_operations fops_power_params = {
+	.write = ath6kl_power_params_write,
+	.open = ath6kl_debugfs_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
 int ath6kl_debug_init(struct ath6kl *ar)
 {
 	ar->debug.fwlog_buf.buf = vmalloc(ATH6KL_FWLOG_SIZE);
@@ -1649,6 +1709,9 @@ int ath6kl_debug_init(struct ath6kl *ar)
 	debugfs_create_file("bgscan_interval", S_IWUSR,
 				ar->debugfs_phy, ar, &fops_bgscan_int);
 
+	debugfs_create_file("power_params", S_IWUSR, ar->debugfs_phy, ar,
+						&fops_power_params);
+
 	return 0;
 }