[PATCH v5 5/5] soc: ti: pruss: Add helper functions to get/set PRUSS_CFG_GPMUX

[MD Danish Anwar <danishanwar@ti.com>]

From: Tero Kristo <t-kristo@ti.com>

Add two new helper functions pruss_cfg_get_gpmux() & pruss_cfg_set_gpmux()
to get and set the GP MUX mode for programming the PRUSS internal wrapper
mux functionality as needed by usecases.

Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/soc/ti/pruss.c           | 44 ++++++++++++++++++++++++++++++++
 include/linux/remoteproc/pruss.h | 30 ++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
index ac415442e85b..3aa3c38c6c79 100644
--- a/drivers/soc/ti/pruss.c
+++ b/drivers/soc/ti/pruss.c
@@ -239,6 +239,50 @@ int pruss_cfg_xfr_enable(struct pruss *pruss, enum pru_type pru_type,
 }
 EXPORT_SYMBOL_GPL(pruss_cfg_xfr_enable);
 
+/**
+ * pruss_cfg_get_gpmux() - get the current GPMUX value for a PRU device
+ * @pruss: pruss instance
+ * @pru_id: PRU identifier (0-1)
+ * @mux: pointer to store the current mux value into
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux)
+{
+	int ret = 0;
+	u32 val;
+
+	if (pru_id < 0 || pru_id >= PRUSS_NUM_PRUS)
+		return -EINVAL;
+
+	ret = pruss_cfg_read(pruss, PRUSS_CFG_GPCFG(pru_id), &val);
+	if (!ret)
+		*mux = (u8)((val & PRUSS_GPCFG_PRU_MUX_SEL_MASK) >>
+			    PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pruss_cfg_get_gpmux);
+
+/**
+ * pruss_cfg_set_gpmux() - set the GPMUX value for a PRU device
+ * @pruss: pruss instance
+ * @pru_id: PRU identifier (0-1)
+ * @mux: new mux value for PRU
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux)
+{
+	if (mux >= PRUSS_GP_MUX_SEL_MAX ||
+	    pru_id < 0 || pru_id >= PRUSS_NUM_PRUS)
+		return -EINVAL;
+
+	return pruss_cfg_update(pruss, PRUSS_CFG_GPCFG(pru_id),
+				PRUSS_GPCFG_PRU_MUX_SEL_MASK,
+				(u32)mux << PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
+}
+EXPORT_SYMBOL_GPL(pruss_cfg_set_gpmux);
+
 static void pruss_of_free_clk_provider(void *data)
 {
 	struct device_node *clk_mux_np = data;
diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
index bb001f712980..42f1586c62ac 100644
--- a/include/linux/remoteproc/pruss.h
+++ b/include/linux/remoteproc/pruss.h
@@ -16,6 +16,24 @@
 
 #define PRU_RPROC_DRVNAME "pru-rproc"
 
+/*
+ * enum pruss_gp_mux_sel - PRUSS GPI/O Mux modes for the
+ * PRUSS_GPCFG0/1 registers
+ *
+ * NOTE: The below defines are the most common values, but there
+ * are some exceptions like on 66AK2G, where the RESERVED and MII2
+ * values are interchanged. Also, this bit-field does not exist on
+ * AM335x SoCs
+ */
+enum pruss_gp_mux_sel {
+	PRUSS_GP_MUX_SEL_GP = 0,
+	PRUSS_GP_MUX_SEL_ENDAT,
+	PRUSS_GP_MUX_SEL_RESERVED,
+	PRUSS_GP_MUX_SEL_SD,
+	PRUSS_GP_MUX_SEL_MII2,
+	PRUSS_GP_MUX_SEL_MAX,
+};
+
 /*
  * enum pruss_gpi_mode - PRUSS GPI configuration modes, used
  *			 to program the PRUSS_GPCFG0/1 registers
@@ -110,6 +128,8 @@ int pruss_cfg_gpimode(struct pruss *pruss, enum pruss_pru_id pru_id,
 int pruss_cfg_miirt_enable(struct pruss *pruss, bool enable);
 int pruss_cfg_xfr_enable(struct pruss *pruss, enum pru_type pru_type,
 			 bool enable);
+int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux);
+int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux);
 
 #else
 
@@ -152,6 +172,16 @@ static inline int pruss_cfg_xfr_enable(struct pruss *pruss,
 	return ERR_PTR(-EOPNOTSUPP);
 }
 
+static inline int pruss_cfg_get_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 *mux)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline int pruss_cfg_set_gpmux(struct pruss *pruss, enum pruss_pru_id pru_id, u8 mux)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
 #endif /* CONFIG_TI_PRUSS */
 
 #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
-- 
2.25.1