reset: add support for the Meson-A1 SoC Reset Controller

The number of RESET registers and offset of RESET_LEVEL register for
Meson-A1 are different from previous SoCs, In order to describe these
differences, we introduce the struct meson_reset_param.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/reset/reset-meson.c

@@ -15,12 +15,16 @@
 #include <linux/types.h>
 #include <linux/of_device.h>
 
-#define REG_COUNT	8
 #define BITS_PER_REG	32
-#define LEVEL_OFFSET	0x7c
+
+struct meson_reset_param {
+	int reg_count;
+	int level_offset;
+};
 
 struct meson_reset {
 	void __iomem *reg_base;
+	const struct meson_reset_param *param;
 	struct reset_controller_dev rcdev;
 	spinlock_t lock;
 };
@@ -46,10 +50,12 @@ static int meson_reset_level(struct reset_controller_dev *rcdev,
 		container_of(rcdev, struct meson_reset, rcdev);
 	unsigned int bank = id / BITS_PER_REG;
 	unsigned int offset = id % BITS_PER_REG;
-	void __iomem *reg_addr = data->reg_base + LEVEL_OFFSET + (bank << 2);
+	void __iomem *reg_addr;
 	unsigned long flags;
 	u32 reg;
 
+	reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
+
 	spin_lock_irqsave(&data->lock, flags);
 
 	reg = readl(reg_addr);
@@ -81,10 +87,21 @@ static const struct reset_control_ops meson_reset_ops = {
 	.deassert	= meson_reset_deassert,
 };
 
+static const struct meson_reset_param meson8b_param = {
+	.reg_count	= 8,
+	.level_offset	= 0x7c,
+};
+
+static const struct meson_reset_param meson_a1_param = {
+	.reg_count	= 3,
+	.level_offset	= 0x40,
+};
+
 static const struct of_device_id meson_reset_dt_ids[] = {
-	 { .compatible = "amlogic,meson8b-reset" },
-	 { .compatible = "amlogic,meson-gxbb-reset" },
-	 { .compatible = "amlogic,meson-axg-reset" },
+	 { .compatible = "amlogic,meson8b-reset",    .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-axg-reset",  .data = &meson8b_param},
+	 { .compatible = "amlogic,meson-a1-reset",   .data = &meson_a1_param},
 	 { /* sentinel */ },
 };
 
@@ -102,12 +119,16 @@ static int meson_reset_probe(struct platform_device *pdev)
 	if (IS_ERR(data->reg_base))
 		return PTR_ERR(data->reg_base);
 
+	data->param = of_device_get_match_data(&pdev->dev);
+	if (!data->param)
+		return -ENODEV;
+
 	platform_set_drvdata(pdev, data);
 
 	spin_lock_init(&data->lock);
 
 	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG;
+	data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
 	data->rcdev.ops = &meson_reset_ops;
 	data->rcdev.of_node = pdev->dev.of_node;