rsi: chip reset for SDIO interface

We need to reset the chip in teardown path so that it can work
next time when driver is loaded. This patch adds support for
this reset configuration for SDIO.

Signed-off-by: Karun Eagalapati <karun256@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 79 insertions, 1 deletions

diff --git a/drivers/net/wireless/rsi/rsi_91x_sdio.c b/drivers/net/wireless/rsi/rsi_91x_sdio.c
index b5ac50394e2b..ebfd29cafbbe 100644
--- a/drivers/net/wireless/rsi/rsi_91x_sdio.c
+++ b/drivers/net/wireless/rsi/rsi_91x_sdio.c
@@ -933,6 +933,84 @@ fail:
 	return 1;
 }
 
+static void ulp_read_write(struct rsi_hw *adapter, u16 addr, u32 data,
+			   u16 len_in_bits)
+{
+	rsi_sdio_master_reg_write(adapter, RSI_GSPI_DATA_REG1,
+				  ((addr << 6) | ((data >> 16) & 0xffff)), 2);
+	rsi_sdio_master_reg_write(adapter, RSI_GSPI_DATA_REG0,
+				  (data & 0xffff), 2);
+	rsi_sdio_master_reg_write(adapter, RSI_GSPI_CTRL_REG0,
+				  RSI_GSPI_CTRL_REG0_VALUE, 2);
+	rsi_sdio_master_reg_write(adapter, RSI_GSPI_CTRL_REG1,
+				  ((len_in_bits - 1) | RSI_GSPI_TRIG), 2);
+	msleep(20);
+}
+
+/*This function resets and re-initializes the chip.*/
+static void rsi_reset_chip(struct rsi_hw *adapter)
+{
+	__le32 data;
+	u8 sdio_interrupt_status = 0;
+	u8 request = 1;
+	int ret;
+
+	rsi_dbg(INFO_ZONE, "Writing disable to wakeup register\n");
+	ret =  rsi_sdio_write_register(adapter, 0, SDIO_WAKEUP_REG, &request);
+	if (ret < 0) {
+		rsi_dbg(ERR_ZONE,
+			"%s: Failed to write SDIO wakeup register\n", __func__);
+		return;
+	}
+	msleep(20);
+	ret =  rsi_sdio_read_register(adapter, RSI_FN1_INT_REGISTER,
+				      &sdio_interrupt_status);
+	if (ret < 0) {
+		rsi_dbg(ERR_ZONE, "%s: Failed to Read Intr Status Register\n",
+			__func__);
+		return;
+	}
+	rsi_dbg(INFO_ZONE, "%s: Intr Status Register value = %d\n",
+		__func__, sdio_interrupt_status);
+
+	/* Put Thread-Arch processor on hold */
+	if (rsi_sdio_master_access_msword(adapter, TA_BASE_ADDR)) {
+		rsi_dbg(ERR_ZONE,
+			"%s: Unable to set ms word to common reg\n",
+			__func__);
+		return;
+	}
+
+	data = TA_HOLD_THREAD_VALUE;
+	if (rsi_sdio_write_register_multiple(adapter, TA_HOLD_THREAD_REG |
+					     RSI_SD_REQUEST_MASTER,
+					     (u8 *)&data, 4)) {
+		rsi_dbg(ERR_ZONE,
+			"%s: Unable to hold Thread-Arch processor threads\n",
+			__func__);
+		return;
+	}
+
+	/* This msleep will ensure Thread-Arch processor to go to hold
+	 * and any pending dma transfers to rf spi in device to finish.
+	 */
+	msleep(100);
+
+	ulp_read_write(adapter, RSI_ULP_RESET_REG, RSI_ULP_WRITE_0, 32);
+	ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_1, RSI_ULP_WRITE_2, 32);
+	ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_2, RSI_ULP_WRITE_0, 32);
+	ulp_read_write(adapter, RSI_WATCH_DOG_DELAY_TIMER_1, RSI_ULP_WRITE_50,
+		       32);
+	ulp_read_write(adapter, RSI_WATCH_DOG_DELAY_TIMER_2, RSI_ULP_WRITE_0,
+		       32);
+	ulp_read_write(adapter, RSI_WATCH_DOG_TIMER_ENABLE,
+		       RSI_ULP_TIMER_ENABLE, 32);
+	/* This msleep will be sufficient for the ulp
+	 * read write operations to complete for chip reset.
+	 */
+	msleep(500);
+}
+
 /**
  * rsi_disconnect() - This function performs the reverse of the probe function.
  * @pfunction: Pointer to the sdio_func structure.
@@ -956,7 +1034,7 @@ static void rsi_disconnect(struct sdio_func *pfunction)
 	sdio_release_irq(pfunction);
 	sdio_disable_func(pfunction);
 	rsi_91x_deinit(adapter);
-	/* Resetting to take care of the case, where-in driver is re-loaded */
+	rsi_reset_chip(adapter);
 	rsi_reset_card(pfunction);
 	sdio_release_host(pfunction);
 }