iwlwifi: pcie: add fake RF-kill to debugfs

In order to debug "hardware" RF-kill flows, add a low-level hook to
allow changing the "hardware" RF-kill from debugfs.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

@@ -404,6 +404,7 @@ struct iwl_trans_pcie {
 	int ict_index;
 	bool use_ict;
 	bool is_down;
+	bool debug_rfkill;
 	struct isr_statistics isr_stats;
 
 	spinlock_t irq_lock;
@@ -675,6 +676,8 @@ static inline void iwl_enable_rfkill_int(struct iwl_trans *trans)
 	}
 }
 
+void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans);
+
 static inline void iwl_wake_queue(struct iwl_trans *trans,
 				  struct iwl_txq *txq)
 {
@@ -713,7 +716,12 @@ static inline u8 get_cmd_index(struct iwl_txq *q, u32 index)
 
 static inline bool iwl_is_rfkill_set(struct iwl_trans *trans)
 {
-	lockdep_assert_held(&IWL_TRANS_GET_PCIE_TRANS(trans)->mutex);
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	lockdep_assert_held(&trans_pcie->mutex);
+
+	if (trans_pcie->debug_rfkill)
+		return true;
 
 	return !(iwl_read32(trans, CSR_GP_CNTRL) &
 		CSR_GP_CNTRL_REG_FLAG_HW_RF_KILL_SW);

drivers/net/wireless/intel/iwlwifi/pcie/rx.c

@@ -1509,7 +1509,7 @@ static u32 iwl_pcie_int_cause_ict(struct iwl_trans *trans)
 	return inta;
 }
 
-static void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans)
+void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -2461,11 +2461,50 @@ static ssize_t iwl_dbgfs_fh_reg_read(struct file *file,
 	return ret;
 }
 
+static ssize_t iwl_dbgfs_rfkill_read(struct file *file,
+				     char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	struct iwl_trans *trans = file->private_data;
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	char buf[100];
+	int pos;
+
+	pos = scnprintf(buf, sizeof(buf), "debug: %d\nhw: %d\n",
+			trans_pcie->debug_rfkill,
+			!(iwl_read32(trans, CSR_GP_CNTRL) &
+				CSR_GP_CNTRL_REG_FLAG_HW_RF_KILL_SW));
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
+static ssize_t iwl_dbgfs_rfkill_write(struct file *file,
+				      const char __user *user_buf,
+				      size_t count, loff_t *ppos)
+{
+	struct iwl_trans *trans = file->private_data;
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	bool old = trans_pcie->debug_rfkill;
+	int ret;
+
+	ret = kstrtobool_from_user(user_buf, count, &trans_pcie->debug_rfkill);
+	if (ret)
+		return ret;
+	if (old == trans_pcie->debug_rfkill)
+		return count;
+	IWL_WARN(trans, "changing debug rfkill %d->%d\n",
+		 old, trans_pcie->debug_rfkill);
+	iwl_pcie_handle_rfkill_irq(trans);
+
+	return count;
+}
+
 DEBUGFS_READ_WRITE_FILE_OPS(interrupt);
 DEBUGFS_READ_FILE_OPS(fh_reg);
 DEBUGFS_READ_FILE_OPS(rx_queue);
 DEBUGFS_READ_FILE_OPS(tx_queue);
 DEBUGFS_WRITE_FILE_OPS(csr);
+DEBUGFS_READ_WRITE_FILE_OPS(rfkill);
 
 /* Create the debugfs files and directories */
 int iwl_trans_pcie_dbgfs_register(struct iwl_trans *trans)
@@ -2477,6 +2516,7 @@ int iwl_trans_pcie_dbgfs_register(struct iwl_trans *trans)
 	DEBUGFS_ADD_FILE(interrupt, dir, S_IWUSR | S_IRUSR);
 	DEBUGFS_ADD_FILE(csr, dir, S_IWUSR);
 	DEBUGFS_ADD_FILE(fh_reg, dir, S_IRUSR);
+	DEBUGFS_ADD_FILE(rfkill, dir, S_IWUSR | S_IRUSR);
 	return 0;
 
 err: