can: c_can: Add support for START pulse in RAMINIT sequence

Some SoCs e.g. (TI DRA7xx) need a START pulse to start the
RAMINIT sequence i.e. START bit must be set and cleared before
checking for the DONE bit status.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 28a73d1..8acdc7f 100644 (file)
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -188,6 +188,7 @@ struct c_can_raminit {
        struct regmap *syscon;  /* for raminit ctrl. reg. access */
        unsigned int reg;       /* register index within syscon */
        struct raminit_bits bits;
+       bool needs_pulse;
 };
 
 /* c_can private data structure */

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 1fbfa1d..41fa460 100644 (file)
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -120,6 +120,12 @@ static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable)
                ctrl |= 1 << raminit->bits.start;
                regmap_write(raminit->syscon, raminit->reg, ctrl);
 
+               /* clear START bit if start pulse is needed */
+               if (raminit->needs_pulse) {
+                       ctrl &= ~(1 << raminit->bits.start);
+                       regmap_write(raminit->syscon, raminit->reg, ctrl);
+               }
+
                ctrl |= 1 << raminit->bits.done;
                c_can_hw_raminit_wait_syscon(priv, mask, ctrl);
        }
@@ -325,6 +331,7 @@ static int c_can_plat_probe(struct platform_device *pdev)
                        }
 
                        raminit->bits = drvdata->raminit_bits[id];
+                       raminit->needs_pulse = drvdata->raminit_pulse;
 
                        priv->raminit = c_can_hw_raminit_syscon;
                } else {