wilc1000: handle read failure issue for clockless registers

For SPI bus, the register read fails after read/write to the clockless
register during chip wakeup sequence. Add workaround to send CMD_RESET
command during chip wake-up sequence to overcome the issue.
Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210916164902.74629-7-ajay.kathat@microchip.com

drivers/net/wireless/microchip/wilc1000/sdio.c

@@ -978,6 +978,7 @@ static const struct wilc_hif_func wilc_hif_sdio = {
 	.hif_sync_ext = wilc_sdio_sync_ext,
 	.enable_interrupt = wilc_sdio_enable_interrupt,
 	.disable_interrupt = wilc_sdio_disable_interrupt,
+	.hif_reset = wilc_sdio_reset,
 };
 
 static int wilc_sdio_resume(struct device *dev)

drivers/net/wireless/microchip/wilc1000/spi.c

@@ -47,6 +47,8 @@ struct wilc_spi {
 
 static const struct wilc_hif_func wilc_hif_spi;
 
+static int wilc_spi_reset(struct wilc *wilc);
+
 /********************************************
  *
  *      Spi protocol Function
@@ -956,6 +958,19 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
  *
  ********************************************/
 
+static int wilc_spi_reset(struct wilc *wilc)
+{
+	struct spi_device *spi = to_spi_device(wilc->dev);
+	struct wilc_spi *spi_priv = wilc->bus_data;
+	int result;
+
+	result = wilc_spi_special_cmd(wilc, CMD_RESET);
+	if (result && !spi_priv->probing_crc)
+		dev_err(&spi->dev, "Failed cmd reset\n");
+
+	return result;
+}
+
 static int wilc_spi_deinit(struct wilc *wilc)
 {
 	/*
@@ -1173,4 +1188,5 @@ static const struct wilc_hif_func wilc_hif_spi = {
 	.hif_block_tx_ext = wilc_spi_write,
 	.hif_block_rx_ext = wilc_spi_read,
 	.hif_sync_ext = wilc_spi_sync_ext,
+	.hif_reset = wilc_spi_reset,
 };

drivers/net/wireless/microchip/wilc1000/wlan.c

@@ -669,6 +669,11 @@ void chip_wakeup(struct wilc *wilc)
 		pr_err("Failed to wake-up the chip\n");
 		return;
 	}
+	/* Sometimes spi fail to read clock regs after reading
+	 * writing clockless registers
+	 */
+	if (wilc->io_type == WILC_HIF_SPI)
+		wilc->hif_func->hif_reset(wilc);
 }
 EXPORT_SYMBOL_GPL(chip_wakeup);
 

drivers/net/wireless/microchip/wilc1000/wlan.h

@@ -373,6 +373,7 @@ struct wilc_hif_func {
 	int (*hif_sync_ext)(struct wilc *wilc, int nint);
 	int (*enable_interrupt)(struct wilc *nic);
 	void (*disable_interrupt)(struct wilc *nic);
+	int (*hif_reset)(struct wilc *wilc);
 };
 
 #define WILC_MAX_CFG_FRAME_SIZE		1468