On 12/22/22 11:28, Krzysztof Kozlowski wrote:
On 21/12/2022 18:30, Gatien Chevallier wrote:
This driver is checking the access rights of the different
peripherals connected to the system bus. If access is denied,
the associated device tree node is skipped so the platform bus
does not probe it.
Signed-off-by: Loic PALLARDY <loic.pallardy@xxxxxx>
Signed-off-by: Gatien Chevallier <gatien.chevallier@xxxxxxxxxxx>
---
MAINTAINERS | 6 ++
drivers/bus/Kconfig | 9 ++
drivers/bus/Makefile | 1 +
drivers/bus/stm32_sys_bus.c | 180 ++++++++++++++++++++++++++++++++++++
4 files changed, 196 insertions(+)
create mode 100644 drivers/bus/stm32_sys_bus.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 886d3f69ee64..768a8272233e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19522,6 +19522,12 @@ L: linux-spi@xxxxxxxxxxxxxxx
S: Maintained
F: drivers/spi/spi-stm32.c
+ST STM32 SYS BUS DRIVER
+M: Gatien Chevallier <gatien.chevallier@xxxxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/bus/st,sys-bus.yaml
+F: drivers/bus/stm32_sys_bus.c
+
ST STPDDC60 DRIVER
M: Daniel Nilsson <daniel.nilsson@xxxxxxxx>
L: linux-hwmon@xxxxxxxxxxxxxxx
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 7bfe998f3514..638bf5839cb0 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -163,6 +163,15 @@ config QCOM_SSC_BLOCK_BUS
i2c/spi/uart controllers, a hexagon core, and a clock controller
which provides clocks for the above.
+config STM32_SYS_BUS
+ bool "STM32 System bus controller"
+ depends on ARCH_STM32
|| COMPILE_TEST
Sure, I will add this in V3
+ default MACH_STM32MP157 || MACH_STM32MP13
+ help
+ Say y to enable device access right verification before device probing.
+ If access not granted, device won't be probed and an error message will
+ provide the reason.
(...)
+
+static int stm32_sys_bus_probe(struct platform_device *pdev)
+{
+ struct sys_bus_data *pdata;
+ struct resource *res;
+ void __iomem *mmio;
+ struct stm32_sys_bus_match_data *mdata;
+ struct device_node *np = pdev->dev.of_node;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mmio = devm_ioremap_resource(&pdev->dev, res);
Use helper for these two.
Ok, I will use devm_platform_ioremap_resource()
+ if (IS_ERR(mmio))
+ return PTR_ERR(mmio);
+
+ pdata->sys_bus_base = mmio;
+
+ mdata = (struct stm32_sys_bus_match_data *)of_device_get_match_data(&pdev->dev);
Why do you need the cast?
I do not :) TBH, mdata is not useful at all. Changing to directly assign
to pdata->pconf, that is now const there is no reason to modify it.
+ if (!mdata)
Can you explain the case when this can actually happen? If it can, you
have bug in ID table.
No I cannot as the driver is probed. It is only a sanity check, I can
remove it for V3. However the function can return NULL... Would you
prefer an explicit check on NULL or a simple removal?
+ return -EINVAL;
+
+ pdata->pconf = mdata;
+ pdata->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, pdata);
+
+ stm32_sys_bus_populate(pdata);
+
+ /* Populate all available nodes */
+ return of_platform_populate(np, NULL, NULL, &pdev->dev);
+}
+
+static const struct stm32_sys_bus_match_data stm32mp15_sys_bus_data = {
+ .max_entries = STM32MP15_ETZPC_ENTRIES,
+ .sys_bus_get_access = stm32_etzpc_get_access,
+};
+
+static const struct stm32_sys_bus_match_data stm32mp13_sys_bus_data = {
+ .max_entries = STM32MP13_ETZPC_ENTRIES,
+ .sys_bus_get_access = stm32_etzpc_get_access,
It's the same as previous, drop.
Yes, ops is useless, I will directly call stm32_etzpc_get_access() in V3.
+};
+
+static const struct of_device_id stm32_sys_bus_of_match[] = {
+ { .compatible = "st,stm32mp15-sys-bus", .data = &stm32mp15_sys_bus_data },
+ { .compatible = "st,stm32mp13-sys-bus", .data = &stm32mp13_sys_bus_data },
+ {}
+};
+MODULE_DEVICE_TABLE(of, stm32_sys_bus_of_match);
+
+static struct platform_driver stm32_sys_bus_driver = {
+ .probe = stm32_sys_bus_probe,
+ .driver = {
+ .name = "stm32-sys-bus",
+ .of_match_table = stm32_sys_bus_of_match,
+ },
+};
+
+static int __init stm32_sys_bus_init(void)
+{
+ return platform_driver_register(&stm32_sys_bus_driver);
+}
+arch_initcall(stm32_sys_bus_init);
+
Best regards,
Krzysztof
Best regards,
Gatien
