Re: [PATCH v7 5/5] clk: aspeed: Add reset controller

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2017-12-22 at 13:15 +1030, Joel Stanley wrote:
> 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>

> ---
> v7:
>   - Rebase on dt-bindings patch
> v5:
>   - Add Andrew's Reviewed-by
> v3:
>   - Add named initalisers for the reset defines
>   - Add define for ADC
> ---
>  drivers/clk/clk-aspeed.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 81 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
> index dbd3c7774831..6fb344730cea 100644
> --- 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) {