[PATCH v2 2/5] apple-gmux: refactor gmux types

Orlando Chamberlain
2023-02-16T12:25:28Z

Add apple_gmux_config struct containing operations and data specific to
each mux type.

This is in preparation for adding a third, MMIO based, gmux type.

Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
---
v1->v2: Handle the two ways of reading the version as part of this type
system (read_version_as_u32).
drivers/platform/x86/apple-gmux.c | 93 ++++++++++++++++++++-----------
include/linux/apple-gmux.h | 18 ++++--
2 files changed, 74 insertions(+), 37 deletions(-)

diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c
index ec99e05e532c..36208e93d745 100644
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@@ -5,6 +5,7 @@
* Copyright (C) Canonical Ltd. <seth.forshee@canonical.com>
* Copyright (C) 2010-2012 Andreas Heider <andreas@meetr.de>
* Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
+ * Copyright (C) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com>
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -43,10 +44,12 @@
* http://www.renesas.com/products/mpumcu/h8s/h8s2100/h8s2113/index.jsp
*/

+struct apple_gmux_config;
+
struct apple_gmux_data {
unsigned long iostart;
unsigned long iolen;
- bool indexed;
+ const struct apple_gmux_config *config;
struct mutex index_lock;

struct backlight_device *bdev;
@@ -64,6 +67,18 @@ struct apple_gmux_data {

static struct apple_gmux_data *apple_gmux_data;

+struct apple_gmux_config {
+ u8 (*read8)(struct apple_gmux_data *gmux_data, int port);
+ void (*write8)(struct apple_gmux_data *gmux_data, int port, u8 val);
+ u32 (*read32)(struct apple_gmux_data *gmux_data, int port);
+ void (*write32)(struct apple_gmux_data *gmux_data, int port, u32 val);
+ const struct vga_switcheroo_handler *gmux_handler;
+ enum vga_switcheroo_handler_flags_t handler_flags;
+ unsigned long resource_type;
+ bool read_version_as_u32;
+ char *name;
+};
+
#define GMUX_INTERRUPT_ENABLE 0xff
#define GMUX_INTERRUPT_DISABLE 0x00

@@ -195,35 +210,23 @@ static void gmux_index_write32(struct apple_gmux_data *gmux_data, int port,

static u8 gmux_read8(struct apple_gmux_data *gmux_data, int port)
{
- if (gmux_data->indexed)
- return gmux_index_read8(gmux_data, port);
- else
- return gmux_pio_read8(gmux_data, port);
+ return gmux_data->config->read8(gmux_data, port);
}

static void gmux_write8(struct apple_gmux_data *gmux_data, int port, u8 val)
{
- if (gmux_data->indexed)
- gmux_index_write8(gmux_data, port, val);
- else
- gmux_pio_write8(gmux_data, port, val);
+ return gmux_data->config->write8(gmux_data, port, val);
}

static u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
{
- if (gmux_data->indexed)
- return gmux_index_read32(gmux_data, port);
- else
- return gmux_pio_read32(gmux_data, port);
+ return gmux_data->config->read32(gmux_data, port);
}

static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
- if (gmux_data->indexed)
- gmux_index_write32(gmux_data, port, val);
- else
- gmux_pio_write32(gmux_data, port, val);
+ return gmux_data->config->write32(gmux_data, port, val);
}

/**
@@ -463,19 +466,43 @@ static enum vga_switcheroo_client_id gmux_get_client_id(struct pci_dev *pdev)
return VGA_SWITCHEROO_DIS;
}

-static const struct vga_switcheroo_handler gmux_handler_indexed = {
+static const struct vga_switcheroo_handler gmux_handler_no_ddc = {
.switchto = gmux_switchto,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};

-static const struct vga_switcheroo_handler gmux_handler_classic = {
+static const struct vga_switcheroo_handler gmux_handler_ddc = {
.switchto = gmux_switchto,
.switch_ddc = gmux_switch_ddc,
.power_state = gmux_set_power_state,
.get_client_id = gmux_get_client_id,
};

+static const struct apple_gmux_config apple_gmux_pio = {
+ .read8 = &gmux_pio_read8,
+ .write8 = &gmux_pio_write8,
+ .read32 = &gmux_pio_read32,
+ .write32 = &gmux_pio_write32,
+ .gmux_handler = &gmux_handler_ddc,
+ .handler_flags = VGA_SWITCHEROO_CAN_SWITCH_DDC,
+ .resource_type = IORESOURCE_IO,
+ .read_version_as_u32 = false,
+ .name = "classic"
+};
+
+static const struct apple_gmux_config apple_gmux_index = {
+ .read8 = &gmux_index_read8,
+ .write8 = &gmux_index_write8,
+ .read32 = &gmux_index_read32,
+ .write32 = &gmux_index_write32,
+ .gmux_handler = &gmux_handler_no_ddc,
+ .handler_flags = VGA_SWITCHEROO_NEEDS_EDP_CONFIG,
+ .resource_type = IORESOURCE_IO,
+ .read_version_as_u32 = true,
+ .name = "indexed"
+};
+
/**
* DOC: Interrupt
*
@@ -565,13 +592,13 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
int ret = -ENXIO;
acpi_status status;
unsigned long long gpe;
- bool indexed = false;
+ enum apple_gmux_type type;
u32 version;

if (apple_gmux_data)
return -EBUSY;

- if (!apple_gmux_detect(pnp, &indexed)) {
+ if (!apple_gmux_detect(pnp, &type)) {
pr_info("gmux device not present\n");
return -ENODEV;
}
@@ -581,6 +608,16 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
return -ENOMEM;
pnp_set_drvdata(pnp, gmux_data);

+ switch (type) {
+ case APPLE_GMUX_TYPE_INDEXED:
+ gmux_data->config = &apple_gmux_index;
+ mutex_init(&gmux_data->index_lock);
+ break;
+ case APPLE_GMUX_TYPE_PIO:
+ gmux_data->config = &apple_gmux_pio;
+ break;
+ }
+
res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
gmux_data->iostart = res->start;
gmux_data->iolen = resource_size(res);
@@ -591,9 +628,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
goto err_free;
}

- if (indexed) {
- mutex_init(&gmux_data->index_lock);
- gmux_data->indexed = true;
+ if (gmux_data->config->read_version_as_u32) {
version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR);
ver_major = (version >> 24) & 0xff;
ver_minor = (version >> 16) & 0xff;
@@ -604,7 +639,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
ver_release = gmux_read8(gmux_data, GMUX_PORT_VERSION_RELEASE);
}
pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
- ver_release, (gmux_data->indexed ? "indexed" : "classic"));
+ ver_release, gmux_data->config->name);

memset(&props, 0, sizeof(props));
props.type = BACKLIGHT_PLATFORM;
@@ -694,12 +729,8 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
*
* Pre-retina MacBook Pros can switch the panel's DDC separately.
*/
- if (gmux_data->indexed)
- ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
- VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
- else
- ret = vga_switcheroo_register_handler(&gmux_handler_classic,
- VGA_SWITCHEROO_CAN_SWITCH_DDC);
+ ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler,
+ gmux_data->config->handler_flags);
if (ret) {
pr_err("Failed to register vga_switcheroo handler\n");
goto err_register_handler;
diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h
index 1f68b49bcd68..5f658439f7f8 100644
--- a/include/linux/apple-gmux.h
+++ b/include/linux/apple-gmux.h
@@ -36,6 +36,11 @@

#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)

+enum apple_gmux_type {
+ APPLE_GMUX_TYPE_PIO,
+ APPLE_GMUX_TYPE_INDEXED
+};
+
#if IS_ENABLED(CONFIG_APPLE_GMUX)
static inline bool apple_gmux_is_indexed(unsigned long iostart)
{
@@ -65,13 +70,13 @@ static inline bool apple_gmux_is_indexed(unsigned long iostart)
* Return: %true if a supported gmux ACPI device is detected and the kernel
* was configured with CONFIG_APPLE_GMUX, %false otherwise.
*/
-static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret)
+static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_type *type_ret)
{
u8 ver_major, ver_minor, ver_release;
struct device *dev = NULL;
struct acpi_device *adev;
struct resource *res;
- bool indexed = false;
+ enum apple_gmux_type type = APPLE_GMUX_TYPE_PIO;
bool ret = false;

if (!pnp_dev) {
@@ -99,13 +104,14 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret)
ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR);
ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE);
if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
- indexed = apple_gmux_is_indexed(res->start);
- if (!indexed)
+ if (apple_gmux_is_indexed(res->start))
+ type = APPLE_GMUX_TYPE_INDEXED;
+ else
goto out;
}

- if (indexed_ret)
- *indexed_ret = indexed;
+ if (type_ret)
+ *type_ret = type;

ret = true;
out:
--
2.39.1