iwlwifi: Adjust blink rate to compensate Clock difference

Adjust led blink rate to compensate on a MAC Clock difference on every
HW. Led blink rate analysis showed an average deviation of 0% on 3945,
5% on 4965 HW and 20% on 5000 series and up.
Need to compensate on the led on/off time per HW according to the
deviation to achieve the desired led frequency
The calculation is: (100-averageDeviation)/100 * blinkTime
For code efficiency the calculation will be:
    compensation = (100 - averageDeviation) * 64 / 100
    NewBlinkTime = (compensation * BlinkTime) / 64

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

7 files changed, 50 insertions, 2 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-1000.c b/drivers/net/wireless/iwlwifi/iwl-1000.c
index 89f360b..1dd8db2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-1000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-1000.c
@@ -164,5 +164,6 @@ struct iwl_cfg iwl1000_bgn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_1000,
 	.shadow_ram_support = false,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index e70c5b0..33e40c2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -2894,6 +2894,7 @@ static struct iwl_cfg iwl3945_bg_cfg = {
 	.mod_params = &iwl3945_mod_params,
 	.use_isr_legacy = true,
 	.ht_greenfield_support = false,
+	.led_compensation = 64,
 };
 
 static struct iwl_cfg iwl3945_abg_cfg = {
@@ -2908,6 +2909,7 @@ static struct iwl_cfg iwl3945_abg_cfg = {
 	.mod_params = &iwl3945_mod_params,
 	.use_isr_legacy = true,
 	.ht_greenfield_support = false,
+	.led_compensation = 64,
 };
 
 struct pci_device_id iwl3945_hw_card_ids[] = {
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index a22a050..2500ab2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2355,6 +2355,7 @@ struct iwl_cfg iwl4965_agn_cfg = {
 	.use_isr_legacy = true,
 	.ht_greenfield_support = false,
 	.broken_powersave = true,
+	.led_compensation = 61,
 };
 
 /* Module firmware */
diff --git a/drivers/net/wireless/iwlwifi/iwl-5000.c b/drivers/net/wireless/iwlwifi/iwl-5000.c
index e1b3785..c81fd4b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-5000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-5000.c
@@ -1656,6 +1656,7 @@ struct iwl_cfg iwl5300_agn_cfg = {
 	.valid_rx_ant = ANT_ABC,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl5100_bg_cfg = {
@@ -1673,6 +1674,7 @@ struct iwl_cfg iwl5100_bg_cfg = {
 	.valid_rx_ant = ANT_AB,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl5100_abg_cfg = {
@@ -1690,6 +1692,7 @@ struct iwl_cfg iwl5100_abg_cfg = {
 	.valid_rx_ant = ANT_AB,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl5100_agn_cfg = {
@@ -1707,6 +1710,7 @@ struct iwl_cfg iwl5100_agn_cfg = {
 	.valid_rx_ant = ANT_AB,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl5350_agn_cfg = {
@@ -1724,6 +1728,7 @@ struct iwl_cfg iwl5350_agn_cfg = {
 	.valid_rx_ant = ANT_ABC,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl5150_agn_cfg = {
@@ -1741,6 +1746,7 @@ struct iwl_cfg iwl5150_agn_cfg = {
 	.valid_rx_ant = ANT_AB,
 	.need_pll_cfg = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 MODULE_FIRMWARE(IWL5000_MODULE_FIRMWARE(IWL5000_UCODE_API_MAX));
diff --git a/drivers/net/wireless/iwlwifi/iwl-6000.c b/drivers/net/wireless/iwlwifi/iwl-6000.c
index 4b3fb40..48b2b7d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-6000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-6000.c
@@ -258,6 +258,7 @@ struct iwl_cfg iwl6000h_2agn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_6x00,
 	.shadow_ram_support = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 /*
@@ -281,6 +282,7 @@ struct iwl_cfg iwl6000i_2agn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_6x00,
 	.shadow_ram_support = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl6050_2agn_cfg = {
@@ -301,6 +303,7 @@ struct iwl_cfg iwl6050_2agn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_6x00,
 	.shadow_ram_support = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl6000_3agn_cfg = {
@@ -321,6 +324,7 @@ struct iwl_cfg iwl6000_3agn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_6x00,
 	.shadow_ram_support = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 struct iwl_cfg iwl6050_3agn_cfg = {
@@ -341,6 +345,7 @@ struct iwl_cfg iwl6050_3agn_cfg = {
 	.max_ll_items = OTP_MAX_LL_ITEMS_6x00,
 	.shadow_ram_support = true,
 	.ht_greenfield_support = true,
+	.led_compensation = 51,
 };
 
 MODULE_FIRMWARE(IWL6000_MODULE_FIRMWARE(IWL6000_UCODE_API_MAX));
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index e50103a..79ea425 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -213,6 +213,9 @@ struct iwl_mod_params {
  * @pa_type: used by 6000 series only to identify the type of Power Amplifier
  * @max_ll_items: max number of OTP blocks
  * @shadow_ram_support: shadow support for OTP memory
+ * @led_compensation: compensate on the led on/off time per HW according
+ *	to the deviation to achieve the desired led frequency.
+ *	The detail algorithm is described in iwl-led.c
  *
  * We enable the driver to be backward compatible wrt API version. The
  * driver specifies which APIs it supports (with @ucode_api_max being the
@@ -255,6 +258,7 @@ struct iwl_cfg {
 	const bool shadow_ram_support;
 	const bool ht_greenfield_support;
 	const bool broken_powersave;
+	u16 led_compensation;
 };
 
 /***************************
diff --git a/drivers/net/wireless/iwlwifi/iwl-led.c b/drivers/net/wireless/iwlwifi/iwl-led.c
index 41addd1..f547233 100644
--- a/drivers/net/wireless/iwlwifi/iwl-led.c
+++ b/drivers/net/wireless/iwlwifi/iwl-led.c
@@ -78,6 +78,29 @@ static const struct {
 #define IWL_MAX_BLINK_TBL (ARRAY_SIZE(blink_tbl) - 1) /* exclude SOLID_ON */
 #define IWL_SOLID_BLINK_IDX (ARRAY_SIZE(blink_tbl) - 1)
 
+/*
+ * Adjust led blink rate to compensate on a MAC Clock difference on every HW
+ * Led blink rate analysis showed an average deviation of 0% on 3945,
+ * 5% on 4965 HW and 20% on 5000 series and up.
+ * Need to compensate on the led on/off time per HW according to the deviation
+ * to achieve the desired led frequency
+ * The calculation is: (100-averageDeviation)/100 * blinkTime
+ * For code efficiency the calculation will be:
+ *     compensation = (100 - averageDeviation) * 64 / 100
+ *     NewBlinkTime = (compensation * BlinkTime) / 64
+ */
+static inline u8 iwl_blink_compensation(struct iwl_priv *priv,
+				    u8 time, u16 compensation)
+{
+	if (!compensation) {
+		IWL_ERR(priv, "undefined blink compensation: "
+			"use pre-defined blinking time\n");
+		return time;
+	}
+
+	return (u8)((time * compensation) >> 6);
+}
+
 /*  [0-256] -> [0..8] FIXME: we need [0..10] */
 static inline int iwl_brightness_to_idx(enum led_brightness brightness)
 {
@@ -114,8 +137,14 @@ static int iwl_led_pattern(struct iwl_priv *priv, int led_id,
 
 	BUG_ON(idx > IWL_MAX_BLINK_TBL);
 
-	led_cmd.on = blink_tbl[idx].on_time;
-	led_cmd.off = blink_tbl[idx].off_time;
+	IWL_DEBUG_LED(priv, "Led blink time compensation= %u\n",
+			priv->cfg->led_compensation);
+	led_cmd.on =
+		iwl_blink_compensation(priv, blink_tbl[idx].on_time,
+					priv->cfg->led_compensation);
+	led_cmd.off =
+		iwl_blink_compensation(priv, blink_tbl[idx].off_time,
+					priv->cfg->led_compensation);
 
 	return iwl_send_led_cmd(priv, &led_cmd);
 }