As discussed when Shannon Zhao sent a patch to add platform_device support
to pl061 driver. Russel and other maintainers prefered that ACPI learned
how to create AMBA devices rather than converting/adding platform_device
support to AMBA drivers.
http://comments.gmane.org/gmane.linux.ports.arm.kernel/431364
1) Adds basic AMBA device probing support to ACPI, it uses a whitelist of
device IDs as the number of AMBA devices is limited. Currently the two ids
present are those used in QEMU for arm64.
2) Adds the plumbing into ACPI probe sequence.
3) From ACPI pl011 is only defined (SBSA document) to be in SBSA mode which has
reduced functionality. There may be a better method to do this that I have
overlooked.
v4:
- A memory leak has been fixed (Vladimir Zapolskiy)
- ACPI_COMPANION() -> has_acpi_companion() (Andy Shevchenko)
- pr_err() -> dev_err() (Andy Shevchenko)
- The call to amba_register_dummy_clk() has been moved to to acpi_amba_init()
(Vladimir Zapolskiy)
- Return value has been fixed (Vladimir Zapolskiy)
v3:
https://lkml.kernel.org/g/[email protected]
- Compilation without CONFIG_ARM_AMBA has been fixed
v2:
https://lkml.kernel.org/g/[email protected]
- A new ACPI scan handler for AMBA devices has been implemented
- The order of `if` branches in amba-pl011.c has been changed
- A couple of `static`s have been added
- The compilation of the acpi_amba.c unit has made conditional
- A comment on SBSA UART has been added
v1:
https://lkml.kernel.org/g/[email protected]
Graeme Gregory (3):
ACPI: amba bus probing support
ACPI: scan add in amba probing
serial: amba-pl011: add ACPI support to AMBA probe
drivers/acpi/Makefile | 1 +
drivers/acpi/acpi_amba.c | 140 ++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 5 ++
drivers/acpi/scan.c | 1 +
drivers/tty/serial/amba-pl011.c | 37 +++++++----
5 files changed, 173 insertions(+), 11 deletions(-)
create mode 100644 drivers/acpi/acpi_amba.c
--
2.6.4
From: Graeme Gregory <[email protected]>
On ARM64 some devices use the AMBA device and not the platform bus for
probing so add support for this. Uses a dummy clock for apb_pclk as ACPI
does not have a suitable clock representation and to keep the core
AMBA bus code unchanged between probing methods.
Signed-off-by: Graeme Gregory <[email protected]>
Signed-off-by: Aleksey Makarov <[email protected]>
---
drivers/acpi/Makefile | 1 +
drivers/acpi/acpi_amba.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 5 ++
3 files changed, 146 insertions(+)
create mode 100644 drivers/acpi/acpi_amba.c
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 675eaf3..3cf732f 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -43,6 +43,7 @@ acpi-y += pci_root.o pci_link.o pci_irq.o
acpi-y += acpi_lpss.o acpi_apd.o
acpi-y += acpi_platform.o
acpi-y += acpi_pnp.o
+acpi-$(CONFIG_ARM_AMBA) += acpi_amba.o
acpi-y += int340x_thermal.o
acpi-y += power.o
acpi-y += event.o
diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
new file mode 100644
index 0000000..4b77d47
--- /dev/null
+++ b/drivers/acpi/acpi_amba.c
@@ -0,0 +1,140 @@
+
+/*
+ * ACPI support for platform bus type.
+ *
+ * Copyright (C) 2015, Linaro Ltd
+ * Authors: Graeme Gregory <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/amba/bus.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+static const struct acpi_device_id amba_id_list[] = {
+ {"ARMH0011", 0}, /* PL011 SBSA Uart */
+ {"ARMH0061", 0}, /* PL061 GPIO Device */
+ {"", 0},
+};
+
+static struct clk *amba_dummy_clk;
+
+static void amba_register_dummy_clk(void)
+{
+ struct clk *clk;
+
+ /* If clock already registered */
+ if (amba_dummy_clk)
+ return;
+
+ clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
+ clk_register_clkdev(clk, "apb_pclk", NULL);
+
+ amba_dummy_clk = clk;
+}
+
+static int amba_handler_attach(struct acpi_device *adev,
+ const struct acpi_device_id *id)
+{
+ struct amba_device *dev = NULL;
+ struct acpi_device *acpi_parent;
+ struct resource_entry *rentry;
+ struct list_head resource_list;
+ bool address_found = false;
+ int ret, irq_no = 0;
+
+ /* If the ACPI node already has a physical device attached, skip it. */
+ if (adev->physical_node_count)
+ return 0;
+
+ dev = amba_device_alloc(NULL, 0, 0);
+ if (!dev) {
+ dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+ if (ret < 0)
+ goto err_free;
+
+ list_for_each_entry(rentry, &resource_list, node) {
+ switch (resource_type(rentry->res)) {
+ case IORESOURCE_MEM:
+ if (!address_found) {
+ dev->res = *rentry->res;
+ address_found = true;
+ }
+ break;
+ case IORESOURCE_IRQ:
+ if (irq_no < AMBA_NR_IRQS)
+ dev->irq[irq_no++] = rentry->res->start;
+ break;
+ default:
+ dev_warn(&adev->dev, "Invalid resource\n");
+ }
+ }
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ /*
+ * If the ACPI node has a parent and that parent has a physical device
+ * attached to it, that physical device should be the parent of the
+ * platform device we are about to create.
+ */
+ dev->dev.parent = NULL;
+ acpi_parent = adev->parent;
+ if (acpi_parent) {
+ struct acpi_device_physical_node *entry;
+ struct list_head *list;
+
+ mutex_lock(&acpi_parent->physical_node_lock);
+ list = &acpi_parent->physical_node_list;
+ if (!list_empty(list)) {
+ entry = list_first_entry(list,
+ struct acpi_device_physical_node,
+ node);
+ dev->dev.parent = entry->dev;
+ }
+ mutex_unlock(&acpi_parent->physical_node_lock);
+ }
+
+ dev_set_name(&dev->dev, "%s", dev_name(&adev->dev));
+ ACPI_COMPANION_SET(&dev->dev, adev);
+
+ ret = amba_device_add(dev, &iomem_resource);
+ if (ret) {
+ dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
+ __func__, ret);
+ goto err_free;
+ }
+
+ return 1;
+
+err_free:
+ amba_device_put(dev);
+ return ret;
+}
+
+static struct acpi_scan_handler amba_handler = {
+ .ids = amba_id_list,
+ .attach = amba_handler_attach,
+};
+
+void __init acpi_amba_init(void)
+{
+ amba_register_dummy_clk();
+ acpi_scan_add_handler(&amba_handler);
+}
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 11d87bf..9d58f0c 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -29,6 +29,11 @@ void acpi_processor_init(void);
void acpi_platform_init(void);
void acpi_pnp_init(void);
void acpi_int340x_thermal_init(void);
+#ifdef CONFIG_ARM_AMBA
+void acpi_amba_init(void);
+#else
+static inline void acpi_amba_init(void) {}
+#endif
int acpi_sysfs_init(void);
void acpi_container_init(void);
void acpi_memory_hotplug_init(void);
--
2.6.4
From: Graeme Gregory <[email protected]>
Add a new ACPI scan handler for AMBA devices.
Signed-off-by: Graeme Gregory <[email protected]>
Signed-off-by: Aleksey Makarov <[email protected]>
---
drivers/acpi/scan.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 78d5f02..20c8cba 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1922,6 +1922,7 @@ int __init acpi_scan_init(void)
acpi_memory_hotplug_init();
acpi_pnp_init();
acpi_int340x_thermal_init();
+ acpi_amba_init();
acpi_scan_add_handler(&generic_device_handler);
--
2.6.4
From: Graeme Gregory <[email protected]>
In ACPI this device is only defined in SBSA mode so
if we are coming from ACPI use this mode.
Signed-off-by: Graeme Gregory <[email protected]>
Signed-off-by: Aleksey Makarov <[email protected]>
---
drivers/tty/serial/amba-pl011.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 899a771..974cb9e 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2368,18 +2368,33 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
if (!uap)
return -ENOMEM;
- uap->clk = devm_clk_get(&dev->dev, NULL);
- if (IS_ERR(uap->clk))
- return PTR_ERR(uap->clk);
-
- uap->vendor = vendor;
- uap->lcrh_rx = vendor->lcrh_rx;
- uap->lcrh_tx = vendor->lcrh_tx;
- uap->fifosize = vendor->get_fifosize(dev);
- uap->port.irq = dev->irq[0];
- uap->port.ops = &amba_pl011_pops;
+ /* ACPI only defines SBSA variant */
+ if (has_acpi_companion(&dev->dev)) {
+ /*
+ * According to ARM ARMH0011 is currently the only mapping
+ * of pl011 in ACPI and it's mapped to SBSA UART mode
+ */
+ uap->vendor = &vendor_sbsa;
+ uap->fifosize = 32;
+ uap->port.ops = &sbsa_uart_pops;
+ uap->fixed_baud = 115200;
- snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
+ snprintf(uap->type, sizeof(uap->type), "SBSA");
+ } else {
+ uap->clk = devm_clk_get(&dev->dev, NULL);
+ if (IS_ERR(uap->clk))
+ return PTR_ERR(uap->clk);
+
+ uap->vendor = vendor;
+ uap->lcrh_rx = vendor->lcrh_rx;
+ uap->lcrh_tx = vendor->lcrh_tx;
+ uap->fifosize = vendor->get_fifosize(dev);
+ uap->port.ops = &amba_pl011_pops;
+
+ snprintf(uap->type, sizeof(uap->type), "PL011 rev%u",
+ amba_rev(dev));
+ }
+ uap->port.irq = dev->irq[0];
ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
if (ret)
--
2.6.4
On Wed, Dec 23, 2015 at 4:19 PM, Aleksey Makarov
<[email protected]> wrote:
> From: Graeme Gregory <[email protected]>
>
> On ARM64 some devices use the AMBA device and not the platform bus for
> probing so add support for this. Uses a dummy clock for apb_pclk as ACPI
> does not have a suitable clock representation and to keep the core
> AMBA bus code unchanged between probing methods.
>
> Signed-off-by: Graeme Gregory <[email protected]>
> Signed-off-by: Aleksey Makarov <[email protected]>
> ---
> drivers/acpi/Makefile | 1 +
> drivers/acpi/acpi_amba.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 5 ++
> 3 files changed, 146 insertions(+)
> create mode 100644 drivers/acpi/acpi_amba.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 675eaf3..3cf732f 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -43,6 +43,7 @@ acpi-y += pci_root.o pci_link.o pci_irq.o
> acpi-y += acpi_lpss.o acpi_apd.o
> acpi-y += acpi_platform.o
> acpi-y += acpi_pnp.o
> +acpi-$(CONFIG_ARM_AMBA) += acpi_amba.o
> acpi-y += int340x_thermal.o
> acpi-y += power.o
> acpi-y += event.o
> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
> new file mode 100644
> index 0000000..4b77d47
> --- /dev/null
> +++ b/drivers/acpi/acpi_amba.c
> @@ -0,0 +1,140 @@
> +
> +/*
> + * ACPI support for platform bus type.
> + *
> + * Copyright (C) 2015, Linaro Ltd
> + * Authors: Graeme Gregory <[email protected]>
Plural form implies more then one author which makes sense after what
you did to the code.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/amba/bus.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk-provider.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include "internal.h"
> +
> +static const struct acpi_device_id amba_id_list[] = {
> + {"ARMH0011", 0}, /* PL011 SBSA Uart */
> + {"ARMH0061", 0}, /* PL061 GPIO Device */
> + {"", 0},
> +};
> +
> +static struct clk *amba_dummy_clk;
You may move this into the function, it will be still global, but
hidden from the namespace.
> +
> +static void amba_register_dummy_clk(void)
> +{
> + struct clk *clk;
> +
> + /* If clock already registered */
> + if (amba_dummy_clk)
> + return;
> +
> + clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
> + clk_register_clkdev(clk, "apb_pclk", NULL);
> +
> + amba_dummy_clk = clk;
> +}
> +
> +static int amba_handler_attach(struct acpi_device *adev,
> + const struct acpi_device_id *id)
> +{
> + struct amba_device *dev = NULL;
Redundant assignment.
> + struct acpi_device *acpi_parent;
> + struct resource_entry *rentry;
> + struct list_head resource_list;
> + bool address_found = false;
> + int ret, irq_no = 0;
Better to split, they are not about the same by meaning.
> +
> + /* If the ACPI node already has a physical device attached, skip it. */
> + if (adev->physical_node_count)
> + return 0;
> +
> + dev = amba_device_alloc(NULL, 0, 0);
> + if (!dev) {
> + dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
> + __func__);
> + return -ENOMEM;
> + }
> +
> + INIT_LIST_HEAD(&resource_list);
> + ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
> + if (ret < 0)
> + goto err_free;
> +
> + list_for_each_entry(rentry, &resource_list, node) {
> + switch (resource_type(rentry->res)) {
> + case IORESOURCE_MEM:
> + if (!address_found) {
> + dev->res = *rentry->res;
> + address_found = true;
> + }
> + break;
> + case IORESOURCE_IRQ:
> + if (irq_no < AMBA_NR_IRQS)
> + dev->irq[irq_no++] = rentry->res->start;
> + break;
> + default:
> + dev_warn(&adev->dev, "Invalid resource\n");
Better to use break here as well.
> + }
> + }
> +
> + acpi_dev_free_resource_list(&resource_list);
> +
> + /*
> + * If the ACPI node has a parent and that parent has a physical device
> + * attached to it, that physical device should be the parent of the
> + * platform device we are about to create.
> + */
> + dev->dev.parent = NULL;
> + acpi_parent = adev->parent;
> + if (acpi_parent) {
> + struct acpi_device_physical_node *entry;
> + struct list_head *list;
> +
> + mutex_lock(&acpi_parent->physical_node_lock);
> + list = &acpi_parent->physical_node_list;
> + if (!list_empty(list)) {
> + entry = list_first_entry(list,
> + struct acpi_device_physical_node,
> + node);
There are couple of users already of the similar.
I would suggest for now to create local helper which we might easily
to move to one of drivers/acpi/ header.
static inline struct acpi_device_physical_node
*to_physical_node(struct acpi_dev *adev)
{
if (list_empty(adev->physical_node_list))
return NULL;
return list_first_entry(adev->physical_node_list, struct
acpi_device_physical_node, node);
}
Rafael, what do you think?
> + dev->dev.parent = entry->dev;
> + }
> + mutex_unlock(&acpi_parent->physical_node_lock);
> + }
> +
> + dev_set_name(&dev->dev, "%s", dev_name(&adev->dev));
> + ACPI_COMPANION_SET(&dev->dev, adev);
> +
> + ret = amba_device_add(dev, &iomem_resource);
> + if (ret) {
> + dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
> + __func__, ret);
> + goto err_free;
> + }
> +
Might be worth to comment out what 1 means here.
> + return 1;
> +
> +err_free:
> + amba_device_put(dev);
> + return ret;
> +}
> +
> +static struct acpi_scan_handler amba_handler = {
> + .ids = amba_id_list,
> + .attach = amba_handler_attach,
> +};
> +
> +void __init acpi_amba_init(void)
> +{
> + amba_register_dummy_clk();
> + acpi_scan_add_handler(&amba_handler);
> +}
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 11d87bf..9d58f0c 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -29,6 +29,11 @@ void acpi_processor_init(void);
> void acpi_platform_init(void);
> void acpi_pnp_init(void);
> void acpi_int340x_thermal_init(void);
Hmm… Looks like we need specific header where drivers can put their
stuff and share with other internal ACPI modules.
> +#ifdef CONFIG_ARM_AMBA
> +void acpi_amba_init(void);
> +#else
> +static inline void acpi_amba_init(void) {}
> +#endif
Same.
> int acpi_sysfs_init(void);
> void acpi_container_init(void);
> void acpi_memory_hotplug_init(void);
> --
> 2.6.4
>
--
With Best Regards,
Andy Shevchenko