[v3,3/7] soc: renesas: rzn1-sysc: Export function to set dmamux

Commit Message

Miquel Raynal Feb. 25, 2022, 11:23 a.m. UTC

The dmamux register is located within the system controller.

Without syscon, we need an extra helper in order to give write access to
this register to a dmamux driver.

Signed-off-by: Miquel Raynal <[e-mail]>
---
 drivers/clk/renesas/r9a06g032-clocks.c        | 35 ++++++++++++++++++-
 include/linux/soc/renesas/r9a06g032-sysctrl.h | 11 ++++++
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/soc/renesas/r9a06g032-sysctrl.h

Patch

diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
index c99942f0e4d4..edcdbe3152f0 100644
--- a/drivers/clk/renesas/r9a06g032-clocks.c
+++ b/drivers/clk/renesas/r9a06g032-clocks.c
@@ -20,9 +20,12 @@ 
 #include <linux/pm_clock.h>
 #include <linux/pm_domain.h>
 #include <linux/slab.h>
+#include <linux/soc/renesas/r9a06g032-sysctrl.h>
 #include <linux/spinlock.h>
 #include <dt-bindings/clock/r9a06g032-sysctrl.h>
 
+#define R9A06G032_SYSCTRL_DMAMUX 0xA0
+
 struct r9a06g032_gate {
 	u16 gate, reset, ready, midle,
 		scon, mirack, mistat;
@@ -315,6 +318,29 @@  struct r9a06g032_priv {
 	void __iomem *reg;
 };
 
+/* Exported helper to access the DMAMUX register */
+static struct r9a06g032_priv *sysctrl_priv;
+int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val)
+{
+	unsigned long flags;
+	u32 dmamux;
+
+	if (!sysctrl_priv)
+		return -EPROBE_DEFER;
+
+	spin_lock_irqsave(&sysctrl_priv->lock, flags);
+
+	dmamux = readl(sysctrl_priv->reg + R9A06G032_SYSCTRL_DMAMUX);
+	dmamux &= ~mask;
+	dmamux |= val & mask;
+	writel(dmamux, sysctrl_priv->reg + R9A06G032_SYSCTRL_DMAMUX);
+
+	spin_unlock_irqrestore(&sysctrl_priv->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(r9a06g032_sysctrl_set_dmamux);
+
 /* register/bit pairs are encoded as an uint16_t */
 static void
 clk_rdesc_set(struct r9a06g032_priv *clocks,
@@ -922,6 +948,7 @@  static int __init r9a06g032_clocks_probe(struct platform_device *pdev)
 	clocks->reg = of_iomap(np, 0);
 	if (WARN_ON(!clocks->reg))
 		return -ENOMEM;
+
 	for (i = 0; i < ARRAY_SIZE(r9a06g032_clocks); ++i) {
 		const struct r9a06g032_clkdesc *d = &r9a06g032_clocks[i];
 		const char *parent_name = d->source ?
@@ -963,7 +990,13 @@  static int __init r9a06g032_clocks_probe(struct platform_device *pdev)
 	if (error)
 		return error;
 
-	return r9a06g032_add_clk_domain(dev);
+	error = r9a06g032_add_clk_domain(dev);
+	if (error)
+		return error;
+
+	sysctrl_priv = clocks;
+
+	return 0;
 }
 
 static const struct of_device_id r9a06g032_match[] = {
diff --git a/include/linux/soc/renesas/r9a06g032-sysctrl.h b/include/linux/soc/renesas/r9a06g032-sysctrl.h
new file mode 100644
index 000000000000..066dfb15cbdd
--- /dev/null
+++ b/include/linux/soc/renesas/r9a06g032-sysctrl.h
@@ -0,0 +1,11 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__
+#define __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__
+
+#ifdef CONFIG_CLK_R9A06G032
+int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val);
+#else
+static inline int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val) { return -ENODEV; }
+#endif
+
+#endif /* __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__ */