clk: aspeed: Add reset controller

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

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
index dbd3c77..6fb3447 100644 (file)
--- a/drivers/clk/clk-aspeed.c
+++ b/drivers/clk/clk-aspeed.c
@@ -8,6 +8,7 @@
 #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>
 
@@ -267,6 +268,68 @@ 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[] = {
+       [ASPEED_RESET_XDMA]     = 25,
+       [ASPEED_RESET_MCTP]     = 24,
+       [ASPEED_RESET_ADC]      = 23,
+       [ASPEED_RESET_JTAG_MASTER] = 22,
+       [ASPEED_RESET_MIC]      = 18,
+       [ASPEED_RESET_PWM]      =  9,
+       [ASPEED_RESET_PCIVGA]   =  8,
+       [ASPEED_RESET_I2C]      =  2,
+       [ASPEED_RESET_AHB]      =  1,
+};
+
+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,
@@ -308,10 +371,11 @@ static int aspeed_clk_probe(struct platform_device *pdev)
 {
        const struct aspeed_clk_soc_data *soc_data;
        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)) {
@@ -319,6 +383,22 @@ static int 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(dev);
        if (!soc_data) {