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.
v3:
- 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 | 149 ++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 5 ++
drivers/acpi/scan.c | 1 +
drivers/tty/serial/amba-pl011.c | 37 +++++++---
5 files changed, 182 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 | 149 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/internal.h | 5 ++
3 files changed, 155 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..ebc8913
--- /dev/null
+++ b/drivers/acpi/acpi_amba.c
@@ -0,0 +1,149 @@
+
+/*
+ * 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;
+ struct resource *resources = NULL;
+ bool address_found = false;
+ int ret, count, irq_no = 0;
+
+ /* If the ACPI node already has a physical device attached, skip it. */
+ if (adev->physical_node_count)
+ return 0;
+
+ amba_register_dummy_clk();
+
+ dev = amba_device_alloc(NULL, 0, 0);
+ if (!dev) {
+ pr_err("%s(): amba_device_alloc() failed for %s\n",
+ __func__, dev_name(&adev->dev));
+ return 0;
+ }
+
+ INIT_LIST_HEAD(&resource_list);
+ count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+ if (count < 0) {
+ return 0;
+ } else if (count > 0) {
+ resources = kmalloc_array(count, sizeof(struct resource),
+ GFP_KERNEL);
+ if (!resources) {
+ acpi_dev_free_resource_list(&resource_list);
+ return 0;
+ }
+ count = 0;
+ 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) {
+ pr_err("%s(): amba_device_add() failed (%d) for %s\n",
+ __func__, ret, dev_name(&adev->dev));
+ goto err_free;
+ }
+
+ return 1;
+
+err_free:
+ amba_device_put(dev);
+ return 0;
+}
+
+static struct acpi_scan_handler amba_handler = {
+ .ids = amba_id_list,
+ .attach = amba_handler_attach,
+};
+
+void __init acpi_amba_init(void)
+{
+ 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..766ce4f 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 (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 Mon, Dec 21, 2015 at 6:41 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 | 149 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 5 ++
> 3 files changed, 155 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..ebc8913
> --- /dev/null
> +++ b/drivers/acpi/acpi_amba.c
> @@ -0,0 +1,149 @@
> +
> +/*
> + * 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;
> + struct resource *resources = NULL;
> + bool address_found = false;
> + int ret, count, irq_no = 0;
> +
> + /* If the ACPI node already has a physical device attached, skip it. */
> + if (adev->physical_node_count)
> + return 0;
> +
> + amba_register_dummy_clk();
> +
> + dev = amba_device_alloc(NULL, 0, 0);
> + if (!dev) {
> + pr_err("%s(): amba_device_alloc() failed for %s\n",
Can it be dev_err(&adev->dev, …); ?
Same for below cases.
> + __func__, dev_name(&adev->dev));
> + return 0;
> + }
> +
> + INIT_LIST_HEAD(&resource_list);
> + count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
> + if (count < 0) {
> + return 0;
> + } else if (count > 0) {
> + resources = kmalloc_array(count, sizeof(struct resource),
> + GFP_KERNEL);
> + if (!resources) {
> + acpi_dev_free_resource_list(&resource_list);
> + return 0;
> + }
> + count = 0;
> + 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) {
> + pr_err("%s(): amba_device_add() failed (%d) for %s\n",
> + __func__, ret, dev_name(&adev->dev));
> + goto err_free;
> + }
> +
> + return 1;
> +
> +err_free:
> + amba_device_put(dev);
> + return 0;
> +}
> +
> +static struct acpi_scan_handler amba_handler = {
> + .ids = amba_id_list,
> + .attach = amba_handler_attach,
> +};
> +
> +void __init acpi_amba_init(void)
> +{
> + 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
With Best Regards,
Andy Shevchenko
On 21 December 2015 at 18:19, Andy Shevchenko <[email protected]> wrote:
> On Mon, Dec 21, 2015 at 6:41 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 | 149 +++++++++++++++++++++++++++++++++++++++++++++++
>> drivers/acpi/internal.h | 5 ++
>> 3 files changed, 155 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..ebc8913
>> --- /dev/null
>> +++ b/drivers/acpi/acpi_amba.c
>> @@ -0,0 +1,149 @@
>> +
>> +/*
>> + * 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;
>> + struct resource *resources = NULL;
>> + bool address_found = false;
>> + int ret, count, irq_no = 0;
>> +
>> + /* If the ACPI node already has a physical device attached, skip it. */
>> + if (adev->physical_node_count)
>> + return 0;
>> +
>> + amba_register_dummy_clk();
>> +
>> + dev = amba_device_alloc(NULL, 0, 0);
>> + if (!dev) {
>> + pr_err("%s(): amba_device_alloc() failed for %s\n",
>
> Can it be dev_err(&adev->dev, …); ?
> Same for below cases.
>
Yes it probably can, I took the code directly from DT version and
didn't think of using adev->dev directly.
Graeme
>> + __func__, dev_name(&adev->dev));
>> + return 0;
>> + }
>> +
>> + INIT_LIST_HEAD(&resource_list);
>
>> + count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
>> + if (count < 0) {
>> + return 0;
>> + } else if (count > 0) {
>> + resources = kmalloc_array(count, sizeof(struct resource),
>> + GFP_KERNEL);
>> + if (!resources) {
>> + acpi_dev_free_resource_list(&resource_list);
>> + return 0;
>> + }
>> + count = 0;
>> + 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) {
>> + pr_err("%s(): amba_device_add() failed (%d) for %s\n",
>> + __func__, ret, dev_name(&adev->dev));
>> + goto err_free;
>> + }
>> +
>> + return 1;
>> +
>> +err_free:
>> + amba_device_put(dev);
>> + return 0;
>> +}
>> +
>> +static struct acpi_scan_handler amba_handler = {
>> + .ids = amba_id_list,
>> + .attach = amba_handler_attach,
>> +};
>> +
>> +void __init acpi_amba_init(void)
>> +{
>> + 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
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
Hi,
On 21.12.2015 18:41, Aleksey Makarov 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 | 149 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 5 ++
> 3 files changed, 155 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..ebc8913
> --- /dev/null
> +++ b/drivers/acpi/acpi_amba.c
> @@ -0,0 +1,149 @@
> +
> +/*
> + * 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;
> + struct resource *resources = NULL;
> + bool address_found = false;
> + int ret, count, irq_no = 0;
> +
> + /* If the ACPI node already has a physical device attached, skip it. */
> + if (adev->physical_node_count)
> + return 0;
> +
> + amba_register_dummy_clk();
Since it is a single time dummy clock registration, may be it is better
to move it to acpi_amba_init() or somewhere else? I understand that
"apb_pclk" is wanted, but I'm not sure that this driver should serve as
a clock provider.
> + dev = amba_device_alloc(NULL, 0, 0);
> + if (!dev) {
> + pr_err("%s(): amba_device_alloc() failed for %s\n",
> + __func__, dev_name(&adev->dev));
> + return 0;
> + }
> +
> + INIT_LIST_HEAD(&resource_list);
> + count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
> + if (count < 0) {
> + return 0;
> + } else if (count > 0) {
if you return from one of two if-branches, please don't use if-else nesting
for another one.
> + resources = kmalloc_array(count, sizeof(struct resource),
> + GFP_KERNEL);
resources is never used and it is never freed, why do you allocate it?
> + if (!resources) {
> + acpi_dev_free_resource_list(&resource_list);
> + return 0;
return -ENOMEM; seems to be more appropriate here.
> + }
> + count = 0;
> + 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) {
> + pr_err("%s(): amba_device_add() failed (%d) for %s\n",
> + __func__, ret, dev_name(&adev->dev));
> + goto err_free;
> + }
> +
> + return 1;
> +
> +err_free:
> + amba_device_put(dev);
> + return 0;
> +}
> +
> +static struct acpi_scan_handler amba_handler = {
> + .ids = amba_id_list,
> + .attach = amba_handler_attach,
> +};
> +
> +void __init acpi_amba_init(void)
> +{
> + 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);
>
--
With best wishes,
Vladimir
On Tue, Dec 22, 2015 at 1:54 AM, Vladimir Zapolskiy <[email protected]> wrote:
> On 21.12.2015 18:41, Aleksey Makarov wrote:
>> +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;
>> + struct resource *resources = NULL;
>> + bool address_found = false;
>> + int ret, count, irq_no = 0;
>> +
>> + /* If the ACPI node already has a physical device attached, skip it. */
>> + if (adev->physical_node_count)
>> + return 0;
>> +
>> + amba_register_dummy_clk();
>
> Since it is a single time dummy clock registration, may be it is better
> to move it to acpi_amba_init() or somewhere else? I understand that
> "apb_pclk" is wanted, but I'm not sure that this driver should serve as
> a clock provider.
Depends on actual hardware topology. Intel HW has few drivers that are
clock providers because they are really ones.
--
With Best Regards,
Andy Shevchenko