[PATCH v2 5/5] clk: aspeed: Add reset controller

From: Joel Stanley
Date: Thu Sep 21 2017 - 00:27:52 EST


There are some resets that are not associated with gates. These are
represented by a reset controller.

Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/clk/clk-aspeed.c | 82 +++++++++++++++++++++++++++++++-
include/dt-bindings/clock/aspeed-clock.h | 9 ++++
2 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index dec9db4ec47b..db97c0f9f99e 100644
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -17,6 +17,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

@@ -256,6 +257,68 @@ static const struct clk_ops aspeed_clk_gate_ops = {
.is_enabled = aspeed_clk_is_enabled,
};

+/**
+ * struct aspeed_reset - Aspeed reset controller
+ * @map: regmap to access the containing system controller
+ * @rcdev: reset controller device
+ */
+struct aspeed_reset {
+ struct regmap *map;
+ struct reset_controller_dev rcdev;
+};
+
+#define to_aspeed_reset(p) container_of((p), struct aspeed_reset, rcdev)
+
+static const u8 aspeed_resets[] = {
+ 25, /* x-dma */
+ 24, /* mctp */
+ 23, /* adc */
+ 22, /* jtag-master */
+ 18, /* mic */
+ 9, /* pwm */
+ 8, /* pci-vga */
+ 2, /* i2c */
+ 1, /* ahb */
+};
+
+static int aspeed_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct aspeed_reset *ar = to_aspeed_reset(rcdev);
+ u32 rst = BIT(aspeed_resets[id]);
+
+ return regmap_update_bits(ar->map, ASPEED_RESET_CTRL, rst, 0);
+}
+
+static int aspeed_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct aspeed_reset *ar = to_aspeed_reset(rcdev);
+ u32 rst = BIT(aspeed_resets[id]);
+
+ return regmap_update_bits(ar->map, ASPEED_RESET_CTRL, rst, rst);
+}
+
+static int aspeed_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct aspeed_reset *ar = to_aspeed_reset(rcdev);
+ u32 val, rst = BIT(aspeed_resets[id]);
+ int ret;
+
+ ret = regmap_read(ar->map, ASPEED_RESET_CTRL, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & rst);
+}
+
+static const struct reset_control_ops aspeed_reset_ops = {
+ .assert = aspeed_reset_assert,
+ .deassert = aspeed_reset_deassert,
+ .status = aspeed_reset_status,
+};
+
static struct clk_hw *aspeed_clk_hw_register_gate(struct device *dev,
const char *name, const char *parent_name, unsigned long flags,
struct regmap *map, u8 clock_idx, u8 reset_idx,
@@ -299,10 +362,11 @@ static int __init aspeed_clk_probe(struct platform_device *pdev)
const struct clk_div_table *mac_div_table;
const struct clk_div_table *div_table;
struct device *dev = &pdev->dev;
+ struct aspeed_reset *ar;
struct regmap *map;
struct clk_hw *hw;
u32 val, rate;
- int i;
+ int i, ret;

map = syscon_node_to_regmap(dev->of_node);
if (IS_ERR(map)) {
@@ -310,6 +374,22 @@ static int __init aspeed_clk_probe(struct platform_device *pdev)
return PTR_ERR(map);
}

+ ar = devm_kzalloc(dev, sizeof(*ar), GFP_KERNEL);
+ if (!ar)
+ return -ENOMEM;
+
+ ar->map = map;
+ ar->rcdev.owner = THIS_MODULE;
+ ar->rcdev.nr_resets = ARRAY_SIZE(aspeed_resets);
+ ar->rcdev.ops = &aspeed_reset_ops;
+ ar->rcdev.of_node = dev->of_node;
+
+ ret = devm_reset_controller_register(dev, &ar->rcdev);
+ if (ret) {
+ dev_err(dev, "could not register reset controller\n");
+ return ret;
+ }
+
/* SoC generations share common layouts but have different divisors */
soc_data = of_device_get_match_data(&pdev->dev);
div_table = soc_data->div_table;
diff --git a/include/dt-bindings/clock/aspeed-clock.h b/include/dt-bindings/clock/aspeed-clock.h
index afe06b77562d..a9d552b6bbd2 100644
--- a/include/dt-bindings/clock/aspeed-clock.h
+++ b/include/dt-bindings/clock/aspeed-clock.h
@@ -40,4 +40,13 @@
#define ASPEED_CLK_GATE_SDCLKCLK (22 + ASPEED_CLK_GATES)
#define ASPEED_CLK_GATE_LHCCLK (23 + ASPEED_CLK_GATES)

+#define ASPEED_RESET_XDMA 0
+#define ASPEED_RESET_MCTP 1
+#define ASPEED_RESET_JTAG_MASTER 2
+#define ASPEED_RESET_MIC 3
+#define ASPEED_RESET_PWM 4
+#define ASPEED_RESET_PCIVGA 5
+#define ASPEED_RESET_I2C 6
+#define ASPEED_RESET_AHB 7
+
#endif
--
2.14.1