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>

3 files changed, 113 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);
 }
diff --git a/drivers/net/wireless/rsi/rsi_hal.h b/drivers/net/wireless/rsi/rsi_hal.h
index 902dc540849c..3179e8606b7e 100644
--- a/drivers/net/wireless/rsi/rsi_hal.h
+++ b/drivers/net/wireless/rsi/rsi_hal.h
@@ -52,6 +52,39 @@
 #define FW_LOADING_SUCCESSFUL		'S'
 #define LOADING_INITIATED		'1'
 
+#define RSI_ULP_RESET_REG		0x161
+#define RSI_WATCH_DOG_TIMER_1		0x16c
+#define RSI_WATCH_DOG_TIMER_2		0x16d
+#define RSI_WATCH_DOG_DELAY_TIMER_1		0x16e
+#define RSI_WATCH_DOG_DELAY_TIMER_2		0x16f
+#define RSI_WATCH_DOG_TIMER_ENABLE		0x170
+
+#define RSI_ULP_WRITE_0			00
+#define RSI_ULP_WRITE_2			02
+#define RSI_ULP_WRITE_50		50
+
+#define RSI_RESTART_WDT			BIT(11)
+#define RSI_BYPASS_ULP_ON_WDT		BIT(1)
+
+#define RSI_ULP_TIMER_ENABLE		((0xaa000) | RSI_RESTART_WDT |	\
+					 RSI_BYPASS_ULP_ON_WDT)
+#define RSI_RF_SPI_PROG_REG_BASE_ADDR	0x40080000
+
+#define RSI_GSPI_CTRL_REG0		(RSI_RF_SPI_PROG_REG_BASE_ADDR)
+#define RSI_GSPI_CTRL_REG1		(RSI_RF_SPI_PROG_REG_BASE_ADDR + 0x2)
+#define RSI_GSPI_DATA_REG0		(RSI_RF_SPI_PROG_REG_BASE_ADDR + 0x4)
+#define RSI_GSPI_DATA_REG1		(RSI_RF_SPI_PROG_REG_BASE_ADDR + 0x6)
+#define RSI_GSPI_DATA_REG2		(RSI_RF_SPI_PROG_REG_BASE_ADDR + 0x8)
+
+#define RSI_GSPI_CTRL_REG0_VALUE		0x340
+
+#define RSI_GSPI_DMA_MODE			BIT(13)
+
+#define RSI_GSPI_2_ULP			BIT(12)
+#define RSI_GSPI_TRIG			BIT(7)
+#define RSI_GSPI_READ			BIT(6)
+#define RSI_GSPI_RF_SPI_ACTIVE		BIT(8)
+
 /* Boot loader commands */
 #define SEND_RPS_FILE			'2'
 
diff --git a/drivers/net/wireless/rsi/rsi_sdio.h b/drivers/net/wireless/rsi/rsi_sdio.h
index 9fb73f68282a..f11f8189e0b6 100644
--- a/drivers/net/wireless/rsi/rsi_sdio.h
+++ b/drivers/net/wireless/rsi/rsi_sdio.h
@@ -58,6 +58,7 @@ enum sdio_interrupt_type {
 #define SDIO_READ_START_LVL                     0x000FC
 #define SDIO_READ_FIFO_CTL                      0x000FD
 #define SDIO_WRITE_FIFO_CTL                     0x000FE
+#define SDIO_WAKEUP_REG				0x000FF
 #define SDIO_FUN1_INTR_CLR_REG                  0x0008
 #define SDIO_REG_HIGH_SPEED                     0x0013