usb: dwc3: Add dwc3 glue driver for am62
Add glue code for TI AM62 to the dwc3 driver; Most code adopted from
TI vendor u-boot code.
Signed-off-by: Sjoerd Simons <sjoerd@collabora.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Tested-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> # on beagle play
diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c
new file mode 100644
index 0000000..9951960
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-am62.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI AM62 specific glue layer for DWC3
+ */
+
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+
+#include "dwc3-generic.h"
+
+#define USBSS_MODE_CONTROL 0x1c
+#define USBSS_PHY_CONFIG 0x8
+#define USBSS_PHY_VBUS_SEL_MASK GENMASK(2, 1)
+#define USBSS_PHY_VBUS_SEL_SHIFT 1
+#define USBSS_MODE_VALID BIT(0)
+#define PHY_PLL_REFCLK_MASK GENMASK(3, 0)
+static const int dwc3_ti_am62_rate_table[] = { /* in KHZ */
+ 9600,
+ 10000,
+ 12000,
+ 19200,
+ 20000,
+ 24000,
+ 25000,
+ 26000,
+ 38400,
+ 40000,
+ 58000,
+ 50000,
+ 52000,
+};
+
+static void dwc3_ti_am62_glue_configure(struct udevice *dev, int index,
+ enum usb_dr_mode mode)
+{
+ struct clk usb2_refclk;
+ int rate_code, i, ret;
+ unsigned long rate;
+ u32 reg;
+ void *usbss;
+ bool vbus_divider;
+ struct regmap *syscon;
+ struct ofnode_phandle_args args;
+
+ usbss = dev_remap_addr_index(dev, 0);
+ if (IS_ERR(usbss)) {
+ dev_err(dev, "can't map IOMEM resource\n");
+ return;
+ }
+
+ ret = clk_get_by_name(dev, "ref", &usb2_refclk);
+ if (ret) {
+ dev_err(dev, "can't get usb2_refclk\n");
+ return;
+ }
+
+ /* Calculate the rate code */
+ rate = clk_get_rate(&usb2_refclk);
+ rate /= 1000; /* To KHz */
+ for (i = 0; i < ARRAY_SIZE(dwc3_ti_am62_rate_table); i++) {
+ if (dwc3_ti_am62_rate_table[i] == rate)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(dwc3_ti_am62_rate_table)) {
+ dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
+ return;
+ }
+
+ rate_code = i;
+
+ /* Read the syscon property */
+ syscon = syscon_regmap_lookup_by_phandle(dev, "ti,syscon-phy-pll-refclk");
+ if (IS_ERR(syscon)) {
+ dev_err(dev, "unable to get ti,syscon-phy-pll-refclk regmap\n");
+ return;
+ }
+
+ ret = ofnode_parse_phandle_with_args(dev_ofnode(dev), "ti,syscon-phy-pll-refclk", NULL, 1,
+ 0, &args);
+ if (ret)
+ return;
+
+ /* Program PHY PLL refclk by reading syscon property */
+ ret = regmap_update_bits(syscon, args.args[0], PHY_PLL_REFCLK_MASK, rate_code);
+ if (ret) {
+ dev_err(dev, "failed to set phy pll reference clock rate\n");
+ return;
+ }
+
+ /* VBUS divider select */
+ reg = readl(usbss + USBSS_PHY_CONFIG);
+ vbus_divider = dev_read_bool(dev, "ti,vbus-divider");
+ if (vbus_divider)
+ reg |= 1 << USBSS_PHY_VBUS_SEL_SHIFT;
+
+ writel(reg, usbss + USBSS_PHY_CONFIG);
+
+ /* Set mode valid */
+ reg = readl(usbss + USBSS_MODE_CONTROL);
+ reg |= USBSS_MODE_VALID;
+ writel(reg, usbss + USBSS_MODE_CONTROL);
+}
+
+struct dwc3_glue_ops ti_am62_ops = {
+ .glue_configure = dwc3_ti_am62_glue_configure,
+};
+
+static const struct udevice_id dwc3_am62_match[] = {
+ { .compatible = "ti,am62-usb", .data = (ulong)&ti_am62_ops },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(dwc3_am62_wrapper) = {
+ .name = "dwc3-am62",
+ .id = UCLASS_SIMPLE_BUS,
+ .of_match = dwc3_am62_match,
+ .bind = dwc3_glue_bind,
+ .probe = dwc3_glue_probe,
+ .remove = dwc3_glue_remove,
+ .plat_auto = sizeof(struct dwc3_glue_data),
+};