ALSA: hda: hdac_controller: Implement support for use_pio_for_commands mode

In case the use_pio_for_commands flag is set we must not enable the
CORB DMA to make sure that it is not interfering with the immediate
command mode.

Convert the snd_hdac_bus_send_cmd/snd_hdac_bus_get_response as wrappers to
call either the PIO or CORB based command handling depending on the
use_pio_for_commands flag.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-ID: <20240409083812.14001-3-peter.ujfalusi@linux.intel.com>

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 7f3a000fab0ce0f9827f215156fb35cffc6c49b6..b5c833b9f8b9cad5bab898b4ec9d1cafb598e013 100644 (file)
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -62,7 +62,8 @@ void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
                azx_clear_corbrp(bus);
 
        /* enable corb dma */
-       snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
+       if (!bus->use_pio_for_commands)
+               snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
 
        /* RIRB set up */
        bus->rirb.addr = bus->rb.addr + 2048;
@@ -135,14 +136,94 @@ static unsigned int azx_command_addr(u32 cmd)
        return addr;
 }
 
+/* receive an Immediate Response with PIO */
+static int snd_hdac_bus_wait_for_pio_response(struct hdac_bus *bus,
+                                             unsigned int addr)
+{
+       int timeout = 50;
+
+       while (timeout--) {
+               /* check IRV bit */
+               if (snd_hdac_chip_readw(bus, IRS) & AZX_IRS_VALID) {
+                       /* reuse rirb.res as the response return value */
+                       bus->rirb.res[addr] = snd_hdac_chip_readl(bus, IR);
+                       return 0;
+               }
+               udelay(1);
+       }
+
+       dev_dbg_ratelimited(bus->dev, "get_response_pio timeout: IRS=%#x\n",
+                           snd_hdac_chip_readw(bus, IRS));
+
+       bus->rirb.res[addr] = -1;
+
+       return -EIO;
+}
+
 /**
- * snd_hdac_bus_send_cmd - send a command verb via CORB
+ * snd_hdac_bus_send_cmd_pio - send a command verb via Immediate Command
  * @bus: HD-audio core bus
  * @val: encoded verb value to send
  *
  * Returns zero for success or a negative error code.
  */
-int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
+static int snd_hdac_bus_send_cmd_pio(struct hdac_bus *bus, unsigned int val)
+{
+       unsigned int addr = azx_command_addr(val);
+       int timeout = 50;
+       int ret = -EIO;
+
+       spin_lock_irq(&bus->reg_lock);
+
+       while (timeout--) {
+               /* check ICB bit */
+               if (!((snd_hdac_chip_readw(bus, IRS) & AZX_IRS_BUSY))) {
+                       /* Clear IRV bit */
+                       snd_hdac_chip_updatew(bus, IRS, AZX_IRS_VALID, AZX_IRS_VALID);
+                       snd_hdac_chip_writel(bus, IC, val);
+                       /* Set ICB bit */
+                       snd_hdac_chip_updatew(bus, IRS, AZX_IRS_BUSY, AZX_IRS_BUSY);
+
+                       ret = snd_hdac_bus_wait_for_pio_response(bus, addr);
+                       goto out;
+               }
+               udelay(1);
+       }
+
+       dev_dbg_ratelimited(bus->dev, "send_cmd_pio timeout: IRS=%#x, val=%#x\n",
+                           snd_hdac_chip_readw(bus, IRS), val);
+
+out:
+       spin_unlock_irq(&bus->reg_lock);
+
+       return ret;
+}
+
+/**
+ * snd_hdac_bus_get_response_pio - receive a response via Immediate Response
+ * @bus: HD-audio core bus
+ * @addr: codec address
+ * @res: pointer to store the value, NULL when not needed
+ *
+ * Returns zero if a value is read, or a negative error code.
+ */
+static int snd_hdac_bus_get_response_pio(struct hdac_bus *bus,
+                                        unsigned int addr, unsigned int *res)
+{
+       if (res)
+               *res = bus->rirb.res[addr];
+
+       return 0;
+}
+
+/**
+ * snd_hdac_bus_send_cmd_corb - send a command verb via CORB
+ * @bus: HD-audio core bus
+ * @val: encoded verb value to send
+ *
+ * Returns zero for success or a negative error code.
+ */
+static int snd_hdac_bus_send_cmd_corb(struct hdac_bus *bus, unsigned int val)
 {
        unsigned int addr = azx_command_addr(val);
        unsigned int wp, rp;
@@ -176,7 +257,6 @@ int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
 
 #define AZX_RIRB_EX_UNSOL_EV   (1<<4)
 
@@ -234,15 +314,15 @@ void snd_hdac_bus_update_rirb(struct hdac_bus *bus)
 EXPORT_SYMBOL_GPL(snd_hdac_bus_update_rirb);
 
 /**
- * snd_hdac_bus_get_response - receive a response via RIRB
+ * snd_hdac_bus_get_response_rirb - receive a response via RIRB
  * @bus: HD-audio core bus
  * @addr: codec address
  * @res: pointer to store the value, NULL when not needed
  *
  * Returns zero if a value is read, or a negative error code.
  */
-int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
-                             unsigned int *res)
+static int snd_hdac_bus_get_response_rirb(struct hdac_bus *bus,
+                                         unsigned int addr, unsigned int *res)
 {
        unsigned long timeout;
        unsigned long loopcounter;
@@ -293,6 +373,39 @@ int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
 
        return -EIO;
 }
+
+/**
+ * snd_hdac_bus_send_cmd - send a command verb via CORB or PIO
+ * @bus: HD-audio core bus
+ * @val: encoded verb value to send
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
+{
+       if (bus->use_pio_for_commands)
+               return snd_hdac_bus_send_cmd_pio(bus, val);
+
+       return snd_hdac_bus_send_cmd_corb(bus, val);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
+
+/**
+ * snd_hdac_bus_get_response - receive a response via RIRB or PIO
+ * @bus: HD-audio core bus
+ * @addr: codec address
+ * @res: pointer to store the value, NULL when not needed
+ *
+ * Returns zero if a value is read, or a negative error code.
+ */
+int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
+                             unsigned int *res)
+{
+       if (bus->use_pio_for_commands)
+               return snd_hdac_bus_get_response_pio(bus, addr, res);
+
+       return snd_hdac_bus_get_response_rirb(bus, addr, res);
+}
 EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);
 
 #define HDAC_MAX_CAPS 10