wilc1000: add reset/terminate/repeat command support for SPI bus

Add reset/terminate/repeat command for SPI module. In case of SPI commands
failure, the host should issue a RESET command to WILC chip to recover
from any temporary bus error.
For now, the new command support is added and later the SPI read/write
API's would be modified to make use of these commands for retry mechanism

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210916164902.74629-6-ajay.kathat@microchip.com

diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c
index dd481dc..602316f 100644 (file)
--- a/drivers/net/wireless/microchip/wilc1000/spi.c
+++ b/drivers/net/wireless/microchip/wilc1000/spi.c
@@ -144,6 +144,12 @@ struct wilc_spi_rsp_data {
        u8 data[];
 } __packed;
 
+struct wilc_spi_special_cmd_rsp {
+       u8 skip_byte;
+       u8 rsp_cmd_type;
+       u8 status;
+} __packed;
+
 static int wilc_bus_probe(struct spi_device *spi)
 {
        int ret;
@@ -709,6 +715,61 @@ static int wilc_spi_dma_rw(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz)
        return 0;
 }
 
+static int wilc_spi_special_cmd(struct wilc *wilc, u8 cmd)
+{
+       struct spi_device *spi = to_spi_device(wilc->dev);
+       struct wilc_spi *spi_priv = wilc->bus_data;
+       u8 wb[32], rb[32];
+       int cmd_len, resp_len = 0;
+       struct wilc_spi_cmd *c;
+       struct wilc_spi_special_cmd_rsp *r;
+
+       if (cmd != CMD_TERMINATE && cmd != CMD_REPEAT && cmd != CMD_RESET)
+               return -EINVAL;
+
+       memset(wb, 0x0, sizeof(wb));
+       memset(rb, 0x0, sizeof(rb));
+       c = (struct wilc_spi_cmd *)wb;
+       c->cmd_type = cmd;
+
+       if (cmd == CMD_RESET)
+               memset(c->u.simple_cmd.addr, 0xFF, 3);
+
+       cmd_len = offsetof(struct wilc_spi_cmd, u.simple_cmd.crc);
+       resp_len = sizeof(*r);
+
+       if (spi_priv->crc7_enabled) {
+               c->u.simple_cmd.crc[0] = wilc_get_crc7(wb, cmd_len);
+               cmd_len += 1;
+       }
+       if (cmd_len + resp_len > ARRAY_SIZE(wb)) {
+               dev_err(&spi->dev, "spi buffer size too small (%d) (%d) (%zu)\n",
+                       cmd_len, resp_len, ARRAY_SIZE(wb));
+               return -EINVAL;
+       }
+
+       if (wilc_spi_tx_rx(wilc, wb, rb, cmd_len + resp_len)) {
+               dev_err(&spi->dev, "Failed cmd write, bus error...\n");
+               return -EINVAL;
+       }
+
+       r = (struct wilc_spi_special_cmd_rsp *)&rb[cmd_len];
+       if (r->rsp_cmd_type != cmd) {
+               if (!spi_priv->probing_crc)
+                       dev_err(&spi->dev,
+                               "Failed cmd response, cmd (%02x), resp (%02x)\n",
+                               cmd, r->rsp_cmd_type);
+               return -EINVAL;
+       }
+
+       if (r->status != WILC_SPI_COMMAND_STAT_SUCCESS) {
+               dev_err(&spi->dev, "Failed cmd state response state (%02x)\n",
+                       r->status);
+               return -EINVAL;
+       }
+       return 0;
+}
+
 static int wilc_spi_read_reg(struct wilc *wilc, u32 addr, u32 *data)
 {
        struct spi_device *spi = to_spi_device(wilc->dev);