[alsa-devel] [PATCH] ALSA: hda/tegra: compatible string as shortname
By default HDA sound card is registered with shortname "tegra-hda". Same driver is used across tegra platforms and it is necessary to distinguish between platforms to use platform specific settings from userspace. One such example is, hdmi port on different platforms use different alsa pcm device ID. For hdmi playback to work it should open correct pcm device depending on the platform.
This patch applies shortname from first compatible string provided in root node of device tree. Userspace then can use this card name to apply specific settings.
Signed-off-by: Sameer Pujar spujar@nvidia.com --- sound/pci/hda/hda_tegra.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c index dd7d424..84ea606 100644 --- a/sound/pci/hda/hda_tegra.c +++ b/sound/pci/hda/hda_tegra.c @@ -31,6 +31,7 @@ #include <linux/of_device.h> #include <linux/slab.h> #include <linux/time.h> +#include <linux/string.h>
#include <sound/core.h> #include <sound/initval.h> @@ -344,6 +345,8 @@ static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev) int err; unsigned short gcap; int irq_id = platform_get_irq(pdev, 0); + const char *sname; + struct device_node *root;
err = hda_tegra_init_chip(chip, pdev); if (err) @@ -401,8 +404,23 @@ static int hda_tegra_first_init(struct azx *chip, struct platform_device *pdev) return -ENODEV; }
+ /* driver name */ strcpy(card->driver, "tegra-hda"); - strcpy(card->shortname, "tegra-hda"); + + root = of_find_node_by_path("/"); + sname = of_get_property(root, "compatible", NULL); + of_node_put(root); + if (!sname) { + dev_err(card->dev, + "failed to get compatible property from root node\n"); + return -ENODEV; + } + /* shortname for card */ + if (strlen(sname) > sizeof(card->shortname)) + dev_info(card->dev, "truncating shortname for card\n"); + strncpy(card->shortname, sname, sizeof(card->shortname)); + + /* longname for card */ snprintf(card->longname, sizeof(card->longname), "%s at 0x%lx irq %i", card->shortname, bus->addr, bus->irq);
On Thu, 29 Nov 2018 04:58:52 +0100, Sameer Pujar wrote:
By default HDA sound card is registered with shortname "tegra-hda". Same driver is used across tegra platforms and it is necessary to distinguish between platforms to use platform specific settings from userspace. One such example is, hdmi port on different platforms use different alsa pcm device ID. For hdmi playback to work it should open correct pcm device depending on the platform.
This patch applies shortname from first compatible string provided in root node of device tree. Userspace then can use this card name to apply specific settings.
Signed-off-by: Sameer Pujar spujar@nvidia.com
Applied, thanks.
Takashi
participants (2)
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Sameer Pujar
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Takashi Iwai