[PATCH 5/7] clk: clocking-wizard: add user clock monitor support

Harry Austen
2024-07-20T12:01:57Z

Xilinx clocking wizard IP core supports monitoring of up to four
optional user clock inputs, with a corresponding interrupt for
notification in change of clock state (stop, underrun, overrun or
glitch). Give userspace access to this monitor logic through use of the
UIO framework.

Use presence of the user monitor interrupt description in devicetree to
indicate whether or not the UIO device should be registered. Also, this
functionality is only supported from v6.0 onwards, so add indication of
support to the device match data, in order to be tied to the utilised
compatible string.

Signed-off-by: Harry Austen <hpausten@protonmail.com>
---
drivers/clk/xilinx/Kconfig | 1 +
drivers/clk/xilinx/clk-xlnx-clock-wizard.c | 67 ++++++++++++++++++++--
2 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/xilinx/Kconfig b/drivers/clk/xilinx/Kconfig
index 051756953558b..907a435694687 100644
--- a/drivers/clk/xilinx/Kconfig
+++ b/drivers/clk/xilinx/Kconfig
@@ -21,6 +21,7 @@ config COMMON_CLK_XLNX_CLKWZRD
tristate "Xilinx Clocking Wizard"
depends on OF
depends on HAS_IOMEM
+ depends on UIO
help
Support for the Xilinx Clocking Wizard IP core clock generator.
Adds support for clocking wizard and compatible.
diff --git a/drivers/clk/xilinx/clk-xlnx-clock-wizard.c b/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
index 7b262d73310fe..2d419e8ad4419 100644
--- a/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
+++ b/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
@@ -20,10 +20,13 @@
#include <linux/overflow.h>
#include <linux/err.h>
#include <linux/iopoll.h>
+#include <linux/uio_driver.h>

#define WZRD_NUM_OUTPUTS 7
#define WZRD_ACLK_MAX_FREQ 250000000UL

+#define WZRD_INTR_ENABLE 0x10
+
#define WZRD_CLK_CFG_REG(v, n) (0x200 + 0x130 * (v) + 4 * (n))

#define WZRD_CLKOUT0_FRAC_EN BIT(18)
@@ -171,8 +174,9 @@ struct clk_wzrd_divider {
spinlock_t *lock; /* divider lock */
};

-struct versal_clk_data {
+struct clk_wzrd_data {
bool is_versal;
+ bool supports_monitor;
};

#define to_clk_wzrd(_nb) container_of(_nb, struct clk_wzrd, nb)
@@ -958,16 +962,55 @@ static int __maybe_unused clk_wzrd_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(clk_wzrd_dev_pm_ops, clk_wzrd_suspend,
clk_wzrd_resume);

-static const struct versal_clk_data versal_data = {
- .is_versal = true,
+static const struct clk_wzrd_data version_6_0_data = {
+ .is_versal = false,
+ .supports_monitor = true,
+};
+
+static const struct clk_wzrd_data versal_data = {
+ .is_versal = true,
+ .supports_monitor = true,
};

+static int clk_wzrd_irqcontrol(struct uio_info *info, s32 irq_on)
+{
+ if (irq_on)
+ iowrite32(GENMASK(15, 0), info->mem[0].internal_addr + WZRD_INTR_ENABLE);
+ else
+ iowrite32(0, info->mem[0].internal_addr + WZRD_INTR_ENABLE);
+
+ return 0;
+}
+
+static int clk_wzrd_setup_monitor(struct device *dev, int irq, const struct resource *res)
+{
+ struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
+ struct uio_info *info;
+
+ info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->name = KBUILD_MODNAME;
+ info->version = "0.0.1";
+
+ info->mem[0].name = "user monitor";
+ info->mem[0].memtype = UIO_MEM_PHYS;
+ info->mem[0].addr = res->start;
+ info->mem[0].size = WZRD_INTR_ENABLE;
+ info->mem[0].internal_addr = clk_wzrd->base;
+
+ info->irq = irq;
+ info->irqcontrol = clk_wzrd_irqcontrol;
+ return devm_uio_register_device(dev, info);
+}
+
static int clk_wzrd_register_output_clocks(struct device *dev, int nr_outputs)
{
const char *clkout_name, *clk_name, *clk_mul_name;
struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
u32 regl, regh, edge, regld, reghd, edged, div;
- const struct versal_clk_data *data;
+ const struct clk_wzrd_data *data;
unsigned long flags = 0;
bool is_versal = false;
void __iomem *ctrl_reg;
@@ -1127,10 +1170,11 @@ static int clk_wzrd_register_output_clocks(struct device *dev, int nr_outputs)
static int clk_wzrd_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
+ const struct clk_wzrd_data *data;
struct clk_wzrd *clk_wzrd;
unsigned long rate;
int nr_outputs;
- int ret;
+ int irq, ret;

clk_wzrd = devm_kzalloc(&pdev->dev, sizeof(*clk_wzrd), GFP_KERNEL);
if (!clk_wzrd)
@@ -1165,6 +1209,17 @@ static int clk_wzrd_probe(struct platform_device *pdev)
return -EINVAL;
}

+ data = device_get_match_data(&pdev->dev);
+ if (data && data->supports_monitor) {
+ irq = platform_get_irq(pdev, 0);
+ if (irq > 0) {
+ ret = clk_wzrd_setup_monitor(&pdev->dev, irq,
+ platform_get_resource(pdev, IORESOURCE_IO, 0));
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to setup monitor\n");
+ }
+ }
+
ret = of_property_read_u32(np, "xlnx,nr-outputs", &nr_outputs);
if (ret || nr_outputs > WZRD_NUM_OUTPUTS)
return -EINVAL;
@@ -1208,7 +1263,7 @@ static const struct of_device_id clk_wzrd_ids[] = {
{ .compatible = "xlnx,versal-clk-wizard", .data = &versal_data },
{ .compatible = "xlnx,clocking-wizard" },
{ .compatible = "xlnx,clocking-wizard-v5.2" },
- { .compatible = "xlnx,clocking-wizard-v6.0" },
+ { .compatible = "xlnx,clocking-wizard-v6.0", .data = &version_6_0_data },
{ },
};
MODULE_DEVICE_TABLE(of, clk_wzrd_ids);
--
2.45.2