Re: [PATCH 1/4] [PATCH 1/4] reset: simple: Add syscon device compatible
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2025-02-14 11:54:20
Also in:
linux-devicetree, lkml
On Do, 2025-02-13 at 22:58 -0800, Wilson Ding wrote:
Introduce the new ops for updating reset line and getting status. Thus, the reset controller can be accessed through either direct I/O or regmap interfaces.
Please don't add a new layer of function pointer indirection, just add a new struct reset_control_ops for the regmap variant.
It enables the support of the syscon devices with the simple reset code. To adapt the DT binding of the syscon device, the number of reset lines must be specified in device data.
If the DT node had a reg property, number of reset lines could be determined from its size, like for MMIO.
quoted hunk ↗ jump to hunk
Signed-off-by: Wilson Ding <redacted> --- drivers/reset/reset-simple.c | 117 +++++++++++++++++++++++------ include/linux/reset/reset-simple.h | 11 +++ 2 files changed, 107 insertions(+), 21 deletions(-)diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c index 276067839830..e4e777d40a79 100644 --- a/drivers/reset/reset-simple.c +++ b/drivers/reset/reset-simple.c@@ -15,8 +15,10 @@ #include <linux/device.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/mfd/syscon.h> #include <linux/of.h> #include <linux/platform_device.h> +#include <linux/regmap.h> #include <linux/reset-controller.h> #include <linux/reset/reset-simple.h> #include <linux/spinlock.h>@@ -27,10 +29,9 @@ to_reset_simple_data(struct reset_controller_dev *rcdev) return container_of(rcdev, struct reset_simple_data, rcdev); } -static int reset_simple_update(struct reset_controller_dev *rcdev, +static int reset_simple_update_mmio(struct reset_simple_data *data, unsigned long id, bool assert)
No need to rename or change the function prototype.
quoted hunk ↗ jump to hunk
{ - struct reset_simple_data *data = to_reset_simple_data(rcdev); int reg_width = sizeof(u32); int bank = id / (reg_width * BITS_PER_BYTE); int offset = id % (reg_width * BITS_PER_BYTE);@@ -51,16 +52,40 @@ static int reset_simple_update(struct reset_controller_dev *rcdev, return 0; } +static int reset_simple_update_regmap(struct reset_simple_data *data, + unsigned long id, bool assert)
I'd call this reset_simple_regmap_update().
+{
+ int reg_width = sizeof(u32);
+ int bank = id / (reg_width * BITS_PER_BYTE);
+ int offset = id % (reg_width * BITS_PER_BYTE);
+ u32 mask, val;
+
+ mask = BIT(offset);
+
+ if (assert ^ data->active_low)
+ val = mask;
+ else
+ val = 0;
+
+ return regmap_write_bits(data->regmap,
+ data->reg_offset + (bank * reg_width),
+ mask, val);
+}
+
static int reset_simple_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
- return reset_simple_update(rcdev, id, true);
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+
+ return data->ops.update(data, id, true);
}
static int reset_simple_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
- return reset_simple_update(rcdev, id, false);
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+
+ return data->ops.update(data, id, false);
}No need for indirection. Better to just add separate reset_simple_regmap_assert/deassert() functions.
quoted hunk ↗ jump to hunk
static int reset_simple_reset(struct reset_controller_dev *rcdev,@@ -81,10 +106,9 @@ static int reset_simple_reset(struct reset_controller_dev *rcdev, return reset_simple_deassert(rcdev, id); } -static int reset_simple_status(struct reset_controller_dev *rcdev, - unsigned long id) +static int reset_simple_status_mmio(struct reset_simple_data *data, + unsigned long id) { - struct reset_simple_data *data = to_reset_simple_data(rcdev); int reg_width = sizeof(u32); int bank = id / (reg_width * BITS_PER_BYTE); int offset = id % (reg_width * BITS_PER_BYTE);@@ -95,6 +119,31 @@ static int reset_simple_status(struct reset_controller_dev *rcdev, return !(reg & BIT(offset)) ^ !data->status_active_low; } +static int reset_simple_status_regmap(struct reset_simple_data *data, + unsigned long id) +{ + int reg_width = sizeof(u32); + int bank = id / (reg_width * BITS_PER_BYTE); + int offset = id % (reg_width * BITS_PER_BYTE); + u32 reg; + int ret; + + ret = regmap_read(data->regmap, data->reg_offset + (bank * reg_width), + ®); + if (ret) + return ret; + + return !(reg & BIT(offset)) ^ !data->status_active_low; +} + +static int reset_simple_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct reset_simple_data *data = to_reset_simple_data(rcdev); + + return data->ops.status(data, id); +}
Same as above, no need for indirection. Just add separate reset_simple_regmap_assert/deassert() functions ...
+
const struct reset_control_ops reset_simple_ops = {
.assert = reset_simple_assert,
.deassert = reset_simple_deassert,... and add a const struct reset_control_ops reset_simple_regmap_ops. regards Philipp