Read in the "snps,ahb-burst" property and set the internal parameter. If this property is set, it overrides the legacy param value, except for BCM2835, which can't set this value.
Cc: Stefan Wahren <[email protected]> Signed-off-by: John Youn <[email protected]> --- drivers/usb/dwc2/core.h | 9 +++++++ drivers/usb/dwc2/params.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index 9548d3e..75c238c 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -430,6 +430,12 @@ enum dwc2_ep0_state { * needed. * 0 - No (default) * 1 - Yes + * @ahb_burst: Specifies the AHB burst. + * 0 - Single + * 1 - INCR + * 3 - INCR4 (default) + * 5 - INCR8 + * 7 - INCR16 * @g_dma: Enables gadget dma usage (default: autodetect). * @g_dma_desc: Enables gadget descriptor DMA (default: autodetect). * @g_rx_fifo_size: The periodic rx fifo size for the device, in @@ -507,6 +513,9 @@ struct dwc2_core_params { * properties and cannot be set directly in this structure. */ + /* Global parameters */ + u8 ahb_burst; + /* Host parameters */ bool host_dma; diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c index a786256..02ccac7 100644 --- a/drivers/usb/dwc2/params.c +++ b/drivers/usb/dwc2/params.c @@ -93,6 +93,13 @@ static const struct dwc2_core_params params_bcm2835 = { .host_ls_low_power_phy_clk = 0, /* 48 MHz */ .ts_dline = 0, .reload_ctl = 0, + + /* + * Although this value would normally be invalid, for BCM2835, + * the GAHBCFG.HBSTLEN field has a different meaning from that + * defined by Synopsys. See the BCM2835 databook section 15.2 + * for details. + */ .ahbcfg = 0x10, .uframe_sched = 0, .external_id_pin_ctl = -1, @@ -1091,6 +1098,66 @@ static void dwc2_set_param_tx_fifo_sizes(struct dwc2_hsotg *hsotg) } } +static const char *const ahb_bursts[] = { + [GAHBCFG_HBSTLEN_SINGLE] = "SINGLE", + [GAHBCFG_HBSTLEN_INCR] = "INCR", + [GAHBCFG_HBSTLEN_INCR4] = "INCR4", + [GAHBCFG_HBSTLEN_INCR8] = "INCR8", + [GAHBCFG_HBSTLEN_INCR16] = "INCR16", +}; + +static int dwc2_get_property_ahb_burst(struct dwc2_hsotg *hsotg) +{ + struct device_node *node = hsotg->dev->of_node; + const char *str = NULL; + int burst; + int ret; + + ret = device_property_read_string(hsotg->dev, + "snps,ahb-burst", &str); + if (ret < 0) { + return ret; + } else if (of_device_is_compatible(node, "brcm,bcm2835-usb")) { + dev_warn(hsotg->dev, + "snps,ahb-burst is not supported on this platform"); + return -EINVAL; + } + + burst = match_string(ahb_bursts, + ARRAY_SIZE(ahb_bursts), str); + if (burst < 0) { + dev_err(hsotg->dev, + "Invalid parameter '%s' for ahb-burst\n", str); + } + + return burst; +} + +static void dwc2_set_ahb_burst(struct dwc2_hsotg *hsotg) +{ + struct dwc2_core_params *p = &hsotg->params; + int burst; + int ret; + + /* Default burst value */ + burst = GAHBCFG_HBSTLEN_INCR4; + + /* Get the legacy param value, if set. */ + if (p->ahbcfg != -1) { + burst = (p->ahbcfg & GAHBCFG_HBSTLEN_MASK) >> + GAHBCFG_HBSTLEN_SHIFT; + } + + /* Override it from devicetree, if set. */ + ret = dwc2_get_property_ahb_burst(hsotg); + if (ret >= 0) + burst = ret; + + /* Set the parameter */ + p->ahb_burst = (u8)burst; + dev_dbg(hsotg->dev, "Setting ahb-burst to %d\n", burst); +} + static void dwc2_set_gadget_dma(struct dwc2_hsotg *hsotg) { struct dwc2_hw_params *hw = &hsotg->hw_params; @@ -1171,6 +1238,8 @@ static void dwc2_set_parameters(struct dwc2_hsotg *hsotg, dwc2_set_param_external_id_pin_ctl(hsotg, params->external_id_pin_ctl); dwc2_set_param_hibernation(hsotg, params->hibernation); + dwc2_set_ahb_burst(hsotg); + /* * Set devicetree-only parameters. These parameters do not * take any values from @params. -- 2.10.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
