[PATCH v5 5/6] firmware: ti_sci: Use dt provided fw name and address to load at suspend time

From: Georgi Vlaev
Date: Mon Nov 28 2022 - 09:06:33 EST


From: Dave Gerlach <d-gerlach@xxxxxx>

Use request_firmware_direct to load the fs stub LPM firmware to a
provided memory region. The filename for the firmware is provided
in the device tree as "firmware-name".

Use a pm_notifier for loading of the low power firmware during
PM_SUSPEND_PREPARE phase so that it can be loaded from the rootfs
before it is suspended. It is possible in the future for this
firmware to require reload, so add a check to indicate that the
firmware is currently loaded so it is only loaded once.

Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Vibhore Vardhan <vibhore@xxxxxx>
Signed-off-by: Georgi Vlaev <g-vlaev@xxxxxx>
Tested-by: Roger Quadros <rogerq@xxxxxxxxxx>
---
drivers/firmware/ti_sci.c | 102 ++++++++++++++++++++++++++++++++++++++
1 file changed, 102 insertions(+)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index b49d81527e29..09bca1a15d74 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -12,6 +12,7 @@
#include <linux/debugfs.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
+#include <linux/firmware.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
@@ -22,6 +23,7 @@
#include <linux/slab.h>
#include <linux/soc/ti/ti-msgmgr.h>
#include <linux/soc/ti/ti_sci_protocol.h>
+#include <linux/suspend.h>
#include <linux/reboot.h>

#include "ti_sci.h"
@@ -89,10 +91,13 @@ struct ti_sci_desc {
* @dev: Device pointer
* @desc: SoC description for this instance
* @nb: Reboot Notifier block
+ * @pm_nb: PM notifier block
* @d: Debugfs file entry
* @debug_region: Memory region where the debug message are available
* @debug_region_size: Debug region size
* @debug_buffer: Buffer allocated to copy debug messages.
+ * @lpm_region: Memory region where the FS Stub LPM Firmware will be stored
+ * @lpm_region_size: LPM region size
* @handle: Instance of TI SCI handle to send to clients.
* @cl: Mailbox Client
* @chan_tx: Transmit mailbox channel
@@ -105,15 +110,20 @@ struct ti_sci_desc {
* @fw_caps: FW/SoC low power capabilities
* @users: Number of users of this instance
* @is_suspending: Flag set to indicate in suspend path.
+ * @lpm_firmware_loaded: Flag to indicate if LPM firmware has been loaded
+ * @lpm_firmware_name: Name of firmware binary to load from fw search path
*/
struct ti_sci_info {
struct device *dev;
struct notifier_block nb;
+ struct notifier_block pm_nb;
const struct ti_sci_desc *desc;
struct dentry *d;
void __iomem *debug_region;
char *debug_buffer;
size_t debug_region_size;
+ void __iomem *lpm_region;
+ size_t lpm_region_size;
struct ti_sci_handle handle;
struct mbox_client cl;
struct mbox_chan *chan_tx;
@@ -127,11 +137,14 @@ struct ti_sci_info {
/* protected by ti_sci_list_mutex */
int users;
bool is_suspending;
+ bool lpm_firmware_loaded;
+ const char *lpm_firmware_name;
};

#define cl_to_ti_sci_info(c) container_of(c, struct ti_sci_info, cl)
#define handle_to_ti_sci_info(h) container_of(h, struct ti_sci_info, handle)
#define reboot_to_ti_sci_info(n) container_of(n, struct ti_sci_info, nb)
+#define pm_nb_to_ti_sci_info(n) container_of(n, struct ti_sci_info, pm_nb)

#ifdef CONFIG_DEBUG_FS

@@ -3524,6 +3537,32 @@ static int tisci_reboot_handler(struct notifier_block *nb, unsigned long mode,
return NOTIFY_BAD;
}

+static int ti_sci_load_lpm_firmware(struct device *dev, struct ti_sci_info *info)
+{
+ const struct firmware *firmware;
+ int ret = 0;
+
+ /* If no firmware name is set, do not attempt to load. */
+ if (!info->lpm_firmware_name)
+ return -EINVAL;
+
+ ret = request_firmware_direct(&firmware, info->lpm_firmware_name, dev);
+ if (ret) {
+ dev_warn(dev, "Cannot load %s\n", info->lpm_firmware_name);
+ return ret;
+ }
+
+ if (firmware->size > info->lpm_region_size) {
+ release_firmware(firmware);
+ return -ENOMEM;
+ }
+
+ memcpy_toio(info->lpm_region, firmware->data, firmware->size);
+
+ release_firmware(firmware);
+
+ return ret;
+}
static void ti_sci_set_is_suspending(struct ti_sci_info *info, bool is_suspending)
{
info->is_suspending = is_suspending;
@@ -3553,10 +3592,33 @@ static int ti_sci_resume(struct device *dev)

static DEFINE_SIMPLE_DEV_PM_OPS(ti_sci_pm_ops, ti_sci_suspend, ti_sci_resume);

+static int tisci_pm_handler(struct notifier_block *nb, unsigned long pm_event,
+ void *unused)
+{
+ struct ti_sci_info *info = pm_nb_to_ti_sci_info(nb);
+ int ret;
+
+ /* Load the LPM firmware on PM_SUSPEND_PREPARE if not loaded yet */
+ if (pm_event != PM_SUSPEND_PREPARE || info->lpm_firmware_loaded)
+ return NOTIFY_DONE;
+
+ ret = ti_sci_load_lpm_firmware(info->dev, info);
+ if (ret) {
+ dev_err(info->dev, "Failed to load LPM firmware (%d)\n", ret);
+ return NOTIFY_BAD;
+ }
+
+ info->lpm_firmware_loaded = true;
+
+ return NOTIFY_OK;
+}
+
static int ti_sci_init_suspend(struct platform_device *pdev,
struct ti_sci_info *info)
{
struct device *dev = &pdev->dev;
+ struct resource *res;
+ int ret;

dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
info->ctx_mem_buf = dma_alloc_coherent(info->dev, LPM_CTX_MEM_SIZE,
@@ -3567,7 +3629,44 @@ static int ti_sci_init_suspend(struct platform_device *pdev,
return -ENOMEM;
}

+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "lpm");
+ if (!res) {
+ dev_warn(dev,
+ "lpm region is required for suspend but not provided.\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ info->lpm_region = devm_ioremap_resource(dev, res);
+ if (IS_ERR(info->lpm_region)) {
+ ret = PTR_ERR(info->lpm_region);
+ goto err;
+ }
+ info->lpm_region_size = resource_size(res);
+
+ if (of_property_read_string(dev->of_node, "firmware-name",
+ &info->lpm_firmware_name)) {
+ dev_warn(dev,
+ "firmware-name is required for suspend but not provided.\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ info->pm_nb.notifier_call = tisci_pm_handler;
+ info->pm_nb.priority = 128;
+
+ ret = register_pm_notifier(&info->pm_nb);
+ if (ret) {
+ dev_err(dev, "pm_notifier registration fail (%d)\n", ret);
+ goto err;
+ }
+
return 0;
+err:
+ dma_free_coherent(info->dev, LPM_CTX_MEM_SIZE,
+ info->ctx_mem_buf,
+ info->ctx_mem_addr);
+ return ret;
}

/* Description for K2G */
@@ -3760,6 +3859,9 @@ static int ti_sci_remove(struct platform_device *pdev)

info = platform_get_drvdata(pdev);

+ if (info->pm_nb.notifier_call)
+ unregister_pm_notifier(&info->pm_nb);
+
if (info->nb.notifier_call)
unregister_restart_handler(&info->nb);

--
2.30.2