Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   <Amisha.Patel@microchip.com>
To:     <linux-wireless@vger.kernel.org>
CC:     <Ajay.Kathat@microchip.com>, <Claudiu.Beznea@microchip.com>,
        <Amisha.Patel@microchip.com>
Subject: [PATCH] wifi: wilc1000: add SPI commands retry mechanism
Thread-Topic: [PATCH] wifi: wilc1000: add SPI commands retry mechanism
Thread-Index: AQHZjzU2TDHO/Hut7kWwqno7z6RMDw==
Date:   Thu, 25 May 2023 18:17:48 +0000
Message-ID: <20230525181739.30063-1-amisha.patel@microchip.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?iso-8859-1?Q?WyS9xd93F/x7QqAGL8oUQmqlQc6ghRJYL/83NXe35X6RRgSU7Mp25Y2YtS?=
 =?iso-8859-1?Q?6p7HOBtU9tqbv2PzpptKhSosHao4gD9kf8OVgGMWnwBwPGftOYHiOR4w+K?=
 =?iso-8859-1?Q?cvUCiLn2dgEKb0bH9qKKckrHLW4SSo81gpmwb8dBFvrD458+JCRpz9bC3g?=
 =?iso-8859-1?Q?O7eiaXcG8pdOHMdl/zsUTw2+k20I1F3ge/S3LG0ViHgUyST/S4ogoMjlS5?=
 =?iso-8859-1?Q?xWHcE0MHWWcJG/4fMivMaQcBKJ9PoW94w3HeXCIBbmc8EXtmG1m1EA1O8p?=
 =?iso-8859-1?Q?bhhe1FDd5fKh8dWFE5ytS6aCUyTP1yy12DwLoJjsglBhkwsyomcc4+RP1k?=
 =?iso-8859-1?Q?FRTumcHJP/zh9RV5BOVn7283IyxdNu8Qc3EDmxZVPAuwPteI+GlyF4aIfa?=
 =?iso-8859-1?Q?DP5CJxe4vD0WgSIVZW10a9uor910+vBmA4vWc6xd+kUG3Hr9ctx52HpEp+?=
 =?iso-8859-1?Q?uTJfu6YmKFuVw0Ss+8RgJzbgD/znFK1HsHzla/xmtWm8cPkIpL7O6d82g+?=
 =?iso-8859-1?Q?CLl7KeI1Gi/GoYaTDvV2QnRbkYs3jlSz/WsiH+UFwDfP4Bw0iqHl9kqM9a?=
 =?iso-8859-1?Q?s7myeKGn8bLIS3sIkmKWPiu1kJ+wNj2HFOhiGwWJ26Cou633DfHiROXsks?=
 =?iso-8859-1?Q?5Ox+527OUp5rEii/Fb3lcbElKkDb44E4WZgN392Ia0s6pwdaoSUw+oFXo3?=
 =?iso-8859-1?Q?9QZeLaE4SO94IR4/fMj3uKu9Ea5cIK0vJum6rtlZxP6iRb6BgjW5yWdxiX?=
 =?iso-8859-1?Q?CIXDziGVeuGSWYtRjn8H6SW9wznjzC+8MQfYrKIbuqiKHL+1vwpkhK4tAv?=
 =?iso-8859-1?Q?onmhViSLov6M6Xo1UQ/VlNE0Ew/WfuE0zlSIkWrBNvcpzOCdVGsn8wNs1r?=
 =?iso-8859-1?Q?cipQGjclsjIQYzXX8kOtmjg45i3R/beD1Q+Y6UROZq1Y73mXljrkLK4EeB?=
 =?iso-8859-1?Q?O4vLhyKE5iTsAQbC56MbYDh8XrD9wp7Es1NFYrJ40S1/jRsr83HWdnY5cB?=
 =?iso-8859-1?Q?0kBnejyrGxLyX21xLv3WjnXtSFkmgnQVRQ5Pfs7HVb443rxPblnBGVPe+f?=
 =?iso-8859-1?Q?Zz9IZrm72576yBKFQ3fuWYDhVxAwkvdhcwtfbAgHI9yc9f3q3mHzeA6458?=
 =?iso-8859-1?Q?z9sPl1OEhq9tutfm6HkyQJAwA54Kcp551plPU3tsyHhMFAxhZdeVrDsrHW?=
 =?iso-8859-1?Q?jyZB6HOL60j2aFdAE6XnL1O0LS7esH+BbEN18vQ8y66T8D8knJZF2inlhw?=
 =?iso-8859-1?Q?2gjqdc9BsqGwXQq0P1JpprePcARtMvPeE1jTyPeDVoMV1BP/q8NRG4MIpu?=
 =?iso-8859-1?Q?BD5b7CM+44aXXgkRESYZ4gwOTLe84IRBjXBh0rf29sryZniaPFKH8ON9lo?=
 =?iso-8859-1?Q?WJ9wV7y0JNbzq6TTnFIed4ZDbpqE4YTIm3dtJ8dQylXShdxgd/OlD14DHx?=
 =?iso-8859-1?Q?tLUX8D67hmqG3AiFmYGvvTXPvu6piNR22ExTxU5Awn/smrOc00/ZBctEVb?=
 =?iso-8859-1?Q?YFkgqdkR9tAOUoCdkSrGdesJLpeCh3VqtAAxN5FJLqscKkF/ZKMMBHd51L?=
 =?iso-8859-1?Q?S3o0m3JINiymYuErd988TgpzHv4Rc5GqIs3uKpcvzz1QJ5IBI5Sc9ItOtD?=
 =?iso-8859-1?Q?2tgwHUy7GRuNwKDjjdispMziF9RL2MAoiAkUC1pVX9Zx3dDeVrnW8c2g?=
 =?iso-8859-1?Q?=3D=3D?=
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: CY8PR11MB7393.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 5a541268-8614-464e-bd9b-08db5d4c58ae
X-MS-Exchange-CrossTenant-originalarrivaltime: 25 May 2023 18:17:48.9330
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 3f4057f3-b418-4d4e-ba84-d55b4e897d88
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: KsREusc5MIEIkGtzyXXnNz+Lw94B2Ttc7I6D46I3v6cT/obg/uuEantOFT2/+XcsMIAheMyU/yJwgpzXWFHpc3umLCgzUUIAsWT67px55Zk=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR11MB5341
X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,
        SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-wireless.vger.kernel.org>
X-Mailing-List: linux-wireless@vger.kernel.org

From: Amisha Patel <amisha.patel@microchip.com>

In some situations like, chip wake-up with powersave enabled, SPI
commands are failing temporarily. Reissuing commands after reset helps
to overcome the failure. So, add the retry limit and reset command
sequence API for read/write SPI commands.

Signed-off-by: Amisha Patel <amisha.patel@microchip.com>
---
 drivers/net/wireless/microchip/wilc1000/spi.c | 96 ++++++++++++++++---
 1 file changed, 83 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wi=
reless/microchip/wilc1000/spi.c
index b0fc5e68feec..35856cdbfb08 100644
--- a/drivers/net/wireless/microchip/wilc1000/spi.c
+++ b/drivers/net/wireless/microchip/wilc1000/spi.c
@@ -74,6 +74,7 @@ static int wilc_spi_reset(struct wilc *wilc);
 #define CMD_SINGLE_READ				0xca
 #define CMD_RESET				0xcf
=20
+#define SPI_RETRY_MAX_LIMIT			10
 #define SPI_ENABLE_VMM_RETRY_LIMIT		2
=20
 /* SPI response fields (section 11.1.2 in ATWILC1000 User Guide): */
@@ -830,23 +831,45 @@ static int wilc_spi_special_cmd(struct wilc *wilc, u8=
 cmd)
 	return 0;
 }
=20
+static void wilc_spi_reset_cmd_sequence(struct wilc *wl, u8 attempt, u32 a=
ddr)
+{
+	struct spi_device *spi =3D to_spi_device(wl->dev);
+	struct wilc_spi *spi_priv =3D wl->bus_data;
+
+	if (!spi_priv->probing_crc)
+		dev_err(&spi->dev, "Reset and retry %d %x\n", attempt, addr);
+
+	usleep_range(1000, 1100);
+	wilc_spi_reset(wl);
+	usleep_range(1000, 1100);
+}
+
 static int wilc_spi_read_reg(struct wilc *wilc, u32 addr, u32 *data)
 {
 	struct spi_device *spi =3D to_spi_device(wilc->dev);
 	int result;
 	u8 cmd =3D CMD_SINGLE_READ;
 	u8 clockless =3D 0;
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
=20
-	if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+	if (addr <=3D WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
 		/* Clockless register */
 		cmd =3D CMD_INTERNAL_READ;
 		clockless =3D 1;
 	}
-
+=09
+retry:
 	result =3D wilc_spi_single_read(wilc, cmd, addr, data, clockless);
 	if (result) {
 		dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
-		return result;
+	=09
+		/* retry is not applicable for clockless registers */
+		if (clockless || !retry_limit)
+			return result;
+
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+		retry_limit--;
+		goto retry;
 	}
=20
 	le32_to_cpus(data);
@@ -858,14 +881,22 @@ static int wilc_spi_read(struct wilc *wilc, u32 addr,=
 u8 *buf, u32 size)
 {
 	struct spi_device *spi =3D to_spi_device(wilc->dev);
 	int result;
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
=20
 	if (size <=3D 4)
 		return -EINVAL;
=20
+retry:
 	result =3D wilc_spi_dma_rw(wilc, CMD_DMA_EXT_READ, addr, buf, size);
 	if (result) {
 		dev_err(&spi->dev, "Failed cmd, read block (%08x)...\n", addr);
-		return result;
+	=09
+		if (!retry_limit)
+			return result;
+
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+		retry_limit--;
+		goto retry;
 	}
=20
 	return 0;
@@ -875,11 +906,19 @@ static int spi_internal_write(struct wilc *wilc, u32 =
adr, u32 dat)
 {
 	struct spi_device *spi =3D to_spi_device(wilc->dev);
 	int result;
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
=20
+retry:
 	result =3D wilc_spi_write_cmd(wilc, CMD_INTERNAL_WRITE, adr, dat, 0);
 	if (result) {
 		dev_err(&spi->dev, "Failed internal write cmd...\n");
-		return result;
+	=09
+		if (!retry_limit)
+			return result;
+
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, adr);
+		retry_limit--;
+		goto retry;
 	}
=20
 	return 0;
@@ -890,12 +929,20 @@ static int spi_internal_read(struct wilc *wilc, u32 a=
dr, u32 *data)
 	struct spi_device *spi =3D to_spi_device(wilc->dev);
 	struct wilc_spi *spi_priv =3D wilc->bus_data;
 	int result;
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
=20
+retry:
 	result =3D wilc_spi_single_read(wilc, CMD_INTERNAL_READ, adr, data, 0);
 	if (result) {
 		if (!spi_priv->probing_crc)
 			dev_err(&spi->dev, "Failed internal read cmd...\n");
-		return result;
+		=09
+		if (!retry_limit)
+			return result;
+
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, adr);
+		retry_limit--;
+		goto retry;
 	}
=20
 	le32_to_cpus(data);
@@ -915,19 +962,26 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 =
addr, u32 data)
 	int result;
 	u8 cmd =3D CMD_SINGLE_WRITE;
 	u8 clockless =3D 0;
-
-	if (addr < WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
+=09
+	if (addr <=3D WILC_SPI_CLOCKLESS_ADDR_LIMIT) {
 		/* Clockless register */
 		cmd =3D CMD_INTERNAL_WRITE;
 		clockless =3D 1;
 	}
=20
+retry:
 	result =3D wilc_spi_write_cmd(wilc, cmd, addr, data, clockless);
 	if (result) {
 		dev_err(&spi->dev, "Failed cmd, write reg (%08x)...\n", addr);
-		return result;
-	}
+	=09
+		if (clockless || !retry_limit)
+			return result;
=20
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+		retry_limit--;
+		goto retry;
+	}
 	return 0;
 }
=20
@@ -981,6 +1035,7 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr,=
 u8 *buf, u32 size)
 {
 	struct spi_device *spi =3D to_spi_device(wilc->dev);
 	int result;
+	u8 retry_limit =3D SPI_RETRY_MAX_LIMIT;
=20
 	/*
 	 * has to be greated than 4
@@ -988,11 +1043,12 @@ static int wilc_spi_write(struct wilc *wilc, u32 add=
r, u8 *buf, u32 size)
 	if (size <=3D 4)
 		return -EINVAL;
=20
+retry:
 	result =3D wilc_spi_dma_rw(wilc, CMD_DMA_EXT_WRITE, addr, NULL, size);
 	if (result) {
 		dev_err(&spi->dev,
 			"Failed cmd, write block (%08x)...\n", addr);
-		return result;
+		goto fail;
 	}
=20
 	/*
@@ -1001,13 +1057,27 @@ static int wilc_spi_write(struct wilc *wilc, u32 ad=
dr, u8 *buf, u32 size)
 	result =3D spi_data_write(wilc, buf, size);
 	if (result) {
 		dev_err(&spi->dev, "Failed block data write...\n");
-		return result;
+		goto fail;
 	}
=20
 	/*
 	 * Data response
 	 */
-	return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+	result =3D spi_data_rsp(wilc, CMD_DMA_EXT_WRITE);
+	if (result) {
+		dev_err(&spi->dev, "Failed block data rsp...\n");
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	if (result && retry_limit) {
+		wilc_spi_reset_cmd_sequence(wilc, retry_limit, addr);
+		retry_limit--;
+		goto retry;
+	}
+	return result;
 }
=20
 /********************************************
--=20
2.25.1