usb: gadget: f_uac2: Support multiple sampling rates
authorJulian Scheel <julian@jusst.de>
Fri, 21 Jan 2022 15:53:03 +0000 (16:53 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 26 Jan 2022 13:06:08 +0000 (14:06 +0100)
A list of sampling rates can be specified via configfs. All enabled
sampling rates are sent to the USB host on request. When the host
selects a sampling rate, the internal active rate (stored in
struct f_uac2) is updated.

The gadget no longer supports only one frequency. Therefore USB strings
corresponding to the clock sources are renamed from specific Hz value to
general names Input clock/Output clock.

Config strings with single value stay compatible with the previous
version.

Multiple samplerates passed as configuration arrays to g_audio module
when built for f_uac2.

Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
Link: https://lore.kernel.org/r/20220121155308.48794-6-pavel.hofman@ivitera.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/ABI/testing/configfs-usb-gadget-uac2
Documentation/usb/gadget-testing.rst
drivers/usb/gadget/function/f_uac2.c
drivers/usb/gadget/function/u_uac2.h
drivers/usb/gadget/legacy/audio.c

index 7fb3dbe..9d2f59a 100644 (file)
@@ -6,7 +6,7 @@ Description:
 
                =====================   =======================================
                c_chmask                capture channel mask
-               c_srate                 capture sampling rate
+               c_srate                 list of capture sampling rates (comma-separated)
                c_ssize                 capture sample size (bytes)
                c_sync                  capture synchronization type
                                        (async/adaptive)
@@ -20,7 +20,7 @@ Description:
                                        (in 1/256 dB)
                fb_max                  maximum extra bandwidth in async mode
                p_chmask                playback channel mask
-               p_srate                 playback sampling rate
+               p_srate                 list of playback sampling rates (comma-separated)
                p_ssize                 playback sample size (bytes)
                p_mute_present          playback mute control enable
                p_volume_present        playback volume control enable
index cbbd948..419f6e5 100644 (file)
@@ -726,7 +726,7 @@ The uac2 function provides these attributes in its function directory:
 
        ================ ====================================================
        c_chmask         capture channel mask
-       c_srate          capture sampling rate
+       c_srate          list of capture sampling rates (comma-separated)
        c_ssize          capture sample size (bytes)
        c_sync           capture synchronization type (async/adaptive)
        c_mute_present   capture mute control enable
@@ -736,7 +736,7 @@ The uac2 function provides these attributes in its function directory:
        c_volume_res     capture volume control resolution (in 1/256 dB)
        fb_max           maximum extra bandwidth in async mode
        p_chmask         playback channel mask
-       p_srate          playback sampling rate
+       p_srate          list of playback sampling rates (comma-separated)
        p_ssize          playback sample size (bytes)
        p_mute_present   playback mute control enable
        p_volume_present playback volume control enable
index e518f21..5ee5314 100644 (file)
@@ -70,6 +70,8 @@ struct f_uac2 {
        /* Interrupt IN endpoint of AC interface */
        struct usb_ep   *int_ep;
        atomic_t        int_count;
+       /* transient state, only valid during handling of a single control request */
+       int clock_id;
 };
 
 static inline struct f_uac2 *func_to_uac2(struct usb_function *f)
@@ -104,14 +106,11 @@ enum {
        STR_AS_IN_ALT1,
 };
 
-static char clksrc_in[8];
-static char clksrc_out[8];
-
 static struct usb_string strings_fn[] = {
        [STR_ASSOC].s = "Source/Sink",
        [STR_IF_CTRL].s = "Topology Control",
-       [STR_CLKSRC_IN].s = clksrc_in,
-       [STR_CLKSRC_OUT].s = clksrc_out,
+       [STR_CLKSRC_IN].s = "Input Clock",
+       [STR_CLKSRC_OUT].s = "Output Clock",
        [STR_USB_IT].s = "USBH Out",
        [STR_IO_IT].s = "USBD Out",
        [STR_USB_OT].s = "USBH In",
@@ -166,7 +165,7 @@ static struct uac_clock_source_descriptor in_clk_src_desc = {
        .bDescriptorSubtype = UAC2_CLOCK_SOURCE,
        /* .bClockID = DYNAMIC */
        .bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
-       .bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
+       .bmControls = (CONTROL_RDWR << CLK_FREQ_CTRL),
        .bAssocTerminal = 0,
 };
 
@@ -178,7 +177,7 @@ static struct uac_clock_source_descriptor out_clk_src_desc = {
        .bDescriptorSubtype = UAC2_CLOCK_SOURCE,
        /* .bClockID = DYNAMIC */
        .bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
-       .bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
+       .bmControls = (CONTROL_RDWR << CLK_FREQ_CTRL),
        .bAssocTerminal = 0,
 };
 
@@ -634,13 +633,37 @@ struct cntrl_cur_lay3 {
        __le32  dCUR;
 };
 
-struct cntrl_range_lay3 {
-       __le16  wNumSubRanges;
+struct cntrl_subrange_lay3 {
        __le32  dMIN;
        __le32  dMAX;
        __le32  dRES;
 } __packed;
 
+#define ranges_lay3_size(c) (sizeof(c.wNumSubRanges)   \
+               + le16_to_cpu(c.wNumSubRanges)          \
+               * sizeof(struct cntrl_subrange_lay3))
+
+#define DECLARE_UAC2_CNTRL_RANGES_LAY3(k, n)           \
+       struct cntrl_ranges_lay3_##k {                  \
+       __le16  wNumSubRanges;                          \
+       struct cntrl_subrange_lay3 r[n];                \
+} __packed
+
+DECLARE_UAC2_CNTRL_RANGES_LAY3(srates, UAC_MAX_RATES);
+
+static int get_max_srate(const int *srates)
+{
+       int i, max_srate = 0;
+
+       for (i = 0; i < UAC_MAX_RATES; i++) {
+               if (srates[i] == 0)
+                       break;
+               if (srates[i] > max_srate)
+                       max_srate = srates[i];
+       }
+       return max_srate;
+}
+
 static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
        struct usb_endpoint_descriptor *ep_desc,
        enum usb_device_speed speed, bool is_playback)
@@ -667,11 +690,11 @@ static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
 
        if (is_playback) {
                chmask = uac2_opts->p_chmask;
-               srate = uac2_opts->p_srate;
+               srate = get_max_srate(uac2_opts->p_srates);
                ssize = uac2_opts->p_ssize;
        } else {
                chmask = uac2_opts->c_chmask;
-               srate = uac2_opts->c_srate;
+               srate = get_max_srate(uac2_opts->c_srates);
                ssize = uac2_opts->c_ssize;
        }
 
@@ -912,10 +935,10 @@ static int afunc_validate_opts(struct g_audio *agdev, struct device *dev)
        } else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
                dev_err(dev, "Error: incorrect capture sample size\n");
                return -EINVAL;
-       } else if (!opts->p_srate) {
+       } else if (!opts->p_srates[0]) {
                dev_err(dev, "Error: incorrect playback sampling rate\n");
                return -EINVAL;
-       } else if (!opts->c_srate) {
+       } else if (!opts->c_srates[0]) {
                dev_err(dev, "Error: incorrect capture sampling rate\n");
                return -EINVAL;
        }
@@ -1037,9 +1060,6 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
                *bma = cpu_to_le32(control);
        }
 
-       snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
-       snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);
-
        ret = usb_interface_id(cfg, fn);
        if (ret < 0) {
                dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
@@ -1209,7 +1229,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
        agdev->gadget = gadget;
 
        agdev->params.p_chmask = uac2_opts->p_chmask;
-       agdev->params.p_srates[0] = uac2_opts->p_srate;
+       memcpy(agdev->params.p_srates, uac2_opts->p_srates,
+                       sizeof(agdev->params.p_srates));
        agdev->params.p_ssize = uac2_opts->p_ssize;
        if (FUIN_EN(uac2_opts)) {
                agdev->params.p_fu.id = USB_IN_FU_ID;
@@ -1220,7 +1241,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
                agdev->params.p_fu.volume_res = uac2_opts->p_volume_res;
        }
        agdev->params.c_chmask = uac2_opts->c_chmask;
-       agdev->params.c_srates[0] = uac2_opts->c_srate;
+       memcpy(agdev->params.c_srates, uac2_opts->c_srates,
+                       sizeof(agdev->params.c_srates));
        agdev->params.c_ssize = uac2_opts->c_ssize;
        if (FUOUT_EN(uac2_opts)) {
                agdev->params.c_fu.id = USB_OUT_FU_ID;
@@ -1423,10 +1445,10 @@ in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
        u8 entity_id = (w_index >> 8) & 0xff;
        u8 control_selector = w_value >> 8;
        int value = -EOPNOTSUPP;
-       int p_srate, c_srate;
+       u32 p_srate, c_srate;
 
-       p_srate = opts->p_srate;
-       c_srate = opts->c_srate;
+       u_audio_get_playback_srate(agdev, &p_srate);
+       u_audio_get_capture_srate(agdev, &c_srate);
 
        if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
                if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
@@ -1500,28 +1522,39 @@ in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
        u8 entity_id = (w_index >> 8) & 0xff;
        u8 control_selector = w_value >> 8;
        int value = -EOPNOTSUPP;
-       int p_srate, c_srate;
-
-       p_srate = opts->p_srate;
-       c_srate = opts->c_srate;
 
        if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
                if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
-                       struct cntrl_range_lay3 r;
+                       struct cntrl_ranges_lay3_srates rs;
+                       int i;
+                       int wNumSubRanges = 0;
+                       int srate;
+                       int *srates;
 
                        if (entity_id == USB_IN_CLK_ID)
-                               r.dMIN = cpu_to_le32(p_srate);
+                               srates = opts->p_srates;
                        else if (entity_id == USB_OUT_CLK_ID)
-                               r.dMIN = cpu_to_le32(c_srate);
+                               srates = opts->c_srates;
                        else
                                return -EOPNOTSUPP;
-
-                       r.dMAX = r.dMIN;
-                       r.dRES = 0;
-                       r.wNumSubRanges = cpu_to_le16(1);
-
-                       value = min_t(unsigned int, w_length, sizeof(r));
-                       memcpy(req->buf, &r, value);
+                       for (i = 0; i < UAC_MAX_RATES; i++) {
+                               srate = srates[i];
+                               if (srate == 0)
+                                       break;
+
+                               rs.r[wNumSubRanges].dMIN = cpu_to_le32(srate);
+                               rs.r[wNumSubRanges].dMAX = cpu_to_le32(srate);
+                               rs.r[wNumSubRanges].dRES = 0;
+                               wNumSubRanges++;
+                               dev_dbg(&agdev->gadget->dev,
+                                       "%s(): clk %d: rate ID %d: %d\n",
+                                       __func__, entity_id, wNumSubRanges, srate);
+                       }
+                       rs.wNumSubRanges = cpu_to_le16(wNumSubRanges);
+                       value = min_t(unsigned int, w_length, ranges_lay3_size(rs));
+                       dev_dbg(&agdev->gadget->dev, "%s(): sending %d rates, size %d\n",
+                               __func__, rs.wNumSubRanges, value);
+                       memcpy(req->buf, &rs, value);
                } else {
                        dev_err(&agdev->gadget->dev,
                                "%s:%d control_selector=%d TODO!\n",
@@ -1580,6 +1613,25 @@ ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
                return -EOPNOTSUPP;
 }
 
+static void uac2_cs_control_sam_freq(struct usb_ep *ep, struct usb_request *req)
+{
+       struct usb_function *fn = ep->driver_data;
+       struct g_audio *agdev = func_to_g_audio(fn);
+       struct f_uac2 *uac2 = func_to_uac2(fn);
+       u32 val;
+
+       if (req->actual != 4)
+               return;
+
+       val = le32_to_cpu(*((__le32 *)req->buf));
+       dev_dbg(&agdev->gadget->dev, "%s val: %d.\n", __func__, val);
+       if (uac2->clock_id == USB_IN_CLK_ID) {
+               u_audio_set_playback_srate(agdev, val);
+       } else if (uac2->clock_id == USB_OUT_CLK_ID) {
+               u_audio_set_capture_srate(agdev, val);
+       }
+}
+
 static void
 out_rq_cur_complete(struct usb_ep *ep, struct usb_request *req)
 {
@@ -1631,6 +1683,7 @@ out_rq_cur_complete(struct usb_ep *ep, struct usb_request *req)
 static int
 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
 {
+       struct usb_composite_dev *cdev = fn->config->cdev;
        struct usb_request *req = fn->config->cdev->req;
        struct g_audio *agdev = func_to_g_audio(fn);
        struct f_uac2_opts *opts = g_audio_to_uac2_opts(agdev);
@@ -1640,10 +1693,17 @@ out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
        u16 w_value = le16_to_cpu(cr->wValue);
        u8 entity_id = (w_index >> 8) & 0xff;
        u8 control_selector = w_value >> 8;
+       u8 clock_id = w_index >> 8;
 
        if ((entity_id == USB_IN_CLK_ID) || (entity_id == USB_OUT_CLK_ID)) {
-               if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
+               if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
+                       dev_dbg(&agdev->gadget->dev,
+                               "control_selector UAC2_CS_CONTROL_SAM_FREQ, clock: %d\n", clock_id);
+                       cdev->gadget->ep0->driver_data = fn;
+                       uac2->clock_id = clock_id;
+                       req->complete = uac2_cs_control_sam_freq;
                        return w_length;
+               }
        } else if ((FUIN_EN(opts) && (entity_id == USB_IN_FU_ID)) ||
                        (FUOUT_EN(opts) && (entity_id == USB_OUT_FU_ID))) {
                memcpy(&uac2->setup_cr, cr, sizeof(*cr));
@@ -1836,11 +1896,70 @@ end:                                                                    \
                                                                        \
 CONFIGFS_ATTR(f_uac2_opts_, name)
 
+#define UAC2_RATE_ATTRIBUTE(name)                                      \
+static ssize_t f_uac2_opts_##name##_show(struct config_item *item,     \
+                                        char *page)                    \
+{                                                                      \
+       struct f_uac2_opts *opts = to_f_uac2_opts(item);                \
+       int result = 0;                                                 \
+       int i;                                                          \
+                                                                       \
+       mutex_lock(&opts->lock);                                        \
+       page[0] = '\0';                                                 \
+       for (i = 0; i < UAC_MAX_RATES; i++) {                           \
+               if (opts->name##s[i] == 0)                              \
+                       break;                                          \
+               result += sprintf(page + strlen(page), "%u,",           \
+                               opts->name##s[i]);                      \
+       }                                                               \
+       if (strlen(page) > 0)                                           \
+               page[strlen(page) - 1] = '\n';                          \
+       mutex_unlock(&opts->lock);                                      \
+                                                                       \
+       return result;                                                  \
+}                                                                      \
+                                                                       \
+static ssize_t f_uac2_opts_##name##_store(struct config_item *item,    \
+                                         const char *page, size_t len) \
+{                                                                      \
+       struct f_uac2_opts *opts = to_f_uac2_opts(item);                \
+       char *split_page = NULL;                                        \
+       int ret = -EINVAL;                                              \
+       char *token;                                                    \
+       u32 num;                                                        \
+       int i;                                                          \
+                                                                       \
+       mutex_lock(&opts->lock);                                        \
+       if (opts->refcnt) {                                             \
+               ret = -EBUSY;                                           \
+               goto end;                                               \
+       }                                                               \
+                                                                       \
+       i = 0;                                                          \
+       memset(opts->name##s, 0x00, sizeof(opts->name##s));             \
+       split_page = kstrdup(page, GFP_KERNEL);                         \
+       while ((token = strsep(&split_page, ",")) != NULL) {            \
+               ret = kstrtou32(token, 0, &num);                        \
+               if (ret)                                                \
+                       goto end;                                       \
+                                                                       \
+               opts->name##s[i++] = num;                               \
+               ret = len;                                              \
+       };                                                              \
+                                                                       \
+end:                                                                   \
+       kfree(split_page);                                              \
+       mutex_unlock(&opts->lock);                                      \
+       return ret;                                                     \
+}                                                                      \
+                                                                       \
+CONFIGFS_ATTR(f_uac2_opts_, name)
+
 UAC2_ATTRIBUTE(u32, p_chmask);
-UAC2_ATTRIBUTE(u32, p_srate);
+UAC2_RATE_ATTRIBUTE(p_srate);
 UAC2_ATTRIBUTE(u32, p_ssize);
 UAC2_ATTRIBUTE(u32, c_chmask);
-UAC2_ATTRIBUTE(u32, c_srate);
+UAC2_RATE_ATTRIBUTE(c_srate);
 UAC2_ATTRIBUTE_SYNC(c_sync);
 UAC2_ATTRIBUTE(u32, c_ssize);
 UAC2_ATTRIBUTE(u32, req_number);
@@ -1913,10 +2032,10 @@ static struct usb_function_instance *afunc_alloc_inst(void)
                                    &f_uac2_func_type);
 
        opts->p_chmask = UAC2_DEF_PCHMASK;
-       opts->p_srate = UAC2_DEF_PSRATE;
+       opts->p_srates[0] = UAC2_DEF_PSRATE;
        opts->p_ssize = UAC2_DEF_PSSIZE;
        opts->c_chmask = UAC2_DEF_CCHMASK;
-       opts->c_srate = UAC2_DEF_CSRATE;
+       opts->c_srates[0] = UAC2_DEF_CSRATE;
        opts->c_ssize = UAC2_DEF_CSSIZE;
        opts->c_sync = UAC2_DEF_CSYNC;
 
index e0c8e35..6bfcf6d 100644 (file)
@@ -14,6 +14,7 @@
 #define U_UAC2_H
 
 #include <linux/usb/composite.h>
+#include "uac_common.h"
 
 #define UAC2_DEF_PCHMASK 0x3
 #define UAC2_DEF_PSRATE 48000
 struct f_uac2_opts {
        struct usb_function_instance    func_inst;
        int                             p_chmask;
-       int                             p_srate;
+       int                             p_srates[UAC_MAX_RATES];
        int                             p_ssize;
        int                             c_chmask;
-       int                             c_srate;
+       int                             c_srates[UAC_MAX_RATES];
        int                             c_ssize;
        int                             c_sync;
 
index 5ec477f..d14b9f2 100644 (file)
@@ -26,9 +26,10 @@ module_param(p_chmask, uint, 0444);
 MODULE_PARM_DESC(p_chmask, "Playback Channel Mask");
 
 /* Playback Default 48 KHz */
-static int p_srate = UAC2_DEF_PSRATE;
-module_param(p_srate, uint, 0444);
-MODULE_PARM_DESC(p_srate, "Playback Sampling Rate");
+static int p_srates[UAC_MAX_RATES] = {UAC2_DEF_PSRATE};
+static int p_srates_cnt = 1;
+module_param_array_named(p_srate, p_srates, uint, &p_srates_cnt, 0444);
+MODULE_PARM_DESC(p_srate, "Playback Sampling Rates (array)");
 
 /* Playback Default 16bits/sample */
 static int p_ssize = UAC2_DEF_PSSIZE;
@@ -41,9 +42,10 @@ module_param(c_chmask, uint, 0444);
 MODULE_PARM_DESC(c_chmask, "Capture Channel Mask");
 
 /* Capture Default 64 KHz */
-static int c_srate = UAC2_DEF_CSRATE;
-module_param(c_srate, uint, 0444);
-MODULE_PARM_DESC(c_srate, "Capture Sampling Rate");
+static int c_srates[UAC_MAX_RATES] = {UAC2_DEF_CSRATE};
+static int c_srates_cnt = 1;
+module_param_array_named(c_srate, c_srates, uint, &c_srates_cnt, 0444);
+MODULE_PARM_DESC(c_srate, "Capture Sampling Rates (array)");
 
 /* Capture Default 16bits/sample */
 static int c_ssize = UAC2_DEF_CSSIZE;
@@ -237,6 +239,7 @@ static int audio_bind(struct usb_composite_dev *cdev)
 {
 #ifndef CONFIG_GADGET_UAC1
        struct f_uac2_opts      *uac2_opts;
+       int i;
 #else
 #ifndef CONFIG_GADGET_UAC1_LEGACY
        struct f_uac1_opts      *uac1_opts;
@@ -263,10 +266,16 @@ static int audio_bind(struct usb_composite_dev *cdev)
 #ifndef CONFIG_GADGET_UAC1
        uac2_opts = container_of(fi_uac2, struct f_uac2_opts, func_inst);
        uac2_opts->p_chmask = p_chmask;
-       uac2_opts->p_srate = p_srate;
+
+       for (i = 0; i < p_srates_cnt; ++i)
+               uac2_opts->p_srates[i] = p_srates[i];
+
        uac2_opts->p_ssize = p_ssize;
        uac2_opts->c_chmask = c_chmask;
-       uac2_opts->c_srate = c_srate;
+
+       for (i = 0; i < c_srates_cnt; ++i)
+               uac2_opts->c_srates[i] = c_srates[i];
+
        uac2_opts->c_ssize = c_ssize;
        uac2_opts->req_number = UAC2_DEF_REQ_NUM;
 #else