video: tegra20: implement a minimal HOST1X driver for essential clock and reset setup
Introduce a simplified HOST1X driver, limited to the basic clock and reset
initialization of the bus.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/video/tegra20/tegra-host1x.c b/drivers/video/tegra20/tegra-host1x.c
new file mode 100644
index 0000000..58ab871
--- /dev/null
+++ b/drivers/video/tegra20/tegra-host1x.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2025 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <dm.h>
+#include <clk.h>
+#include <log.h>
+#include <reset.h>
+#include <linux/delay.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/clk_rst.h>
+
+struct tegra_host1x_info {
+ u32 clk_parent;
+ u32 rate;
+};
+
+static int tegra_host1x_probe(struct udevice *dev)
+{
+ struct clk *clk;
+ struct reset_ctl reset_ctl;
+ const struct tegra_host1x_info *info;
+ int ret;
+
+ clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(clk)) {
+ log_debug("%s: cannot get HOST1X clock: %ld\n",
+ __func__, PTR_ERR(clk));
+ return PTR_ERR(clk);
+ }
+
+ ret = reset_get_by_name(dev, "host1x", &reset_ctl);
+ if (ret) {
+ log_debug("%s: cannot get HOST1X reset: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ info = (struct tegra_host1x_info *)dev_get_driver_data(dev);
+
+ reset_assert(&reset_ctl);
+ clock_start_periph_pll(clk->id, info->clk_parent, info->rate);
+
+ mdelay(2);
+ reset_deassert(&reset_ctl);
+
+ return 0;
+}
+
+static const struct tegra_host1x_info tegra20_host1x_info = {
+ .clk_parent = CLOCK_ID_CGENERAL,
+ .rate = 150000000, /* 150 MHz */
+};
+
+static const struct tegra_host1x_info tegra114_host1x_info = {
+ .clk_parent = CLOCK_ID_PERIPH,
+ .rate = 136000000, /* 136 MHz */
+};
+
+static const struct udevice_id tegra_host1x_ids[] = {
+ {
+ .compatible = "nvidia,tegra20-host1x",
+ .data = (ulong)&tegra20_host1x_info
+ }, {
+ .compatible = "nvidia,tegra30-host1x",
+ .data = (ulong)&tegra20_host1x_info
+ }, {
+ .compatible = "nvidia,tegra114-host1x",
+ .data = (ulong)&tegra114_host1x_info
+ }, {
+ .compatible = "nvidia,tegra124-host1x",
+ .data = (ulong)&tegra114_host1x_info
+ }, {
+ /* sentinel */
+ }
+};
+
+U_BOOT_DRIVER(tegra_host1x) = {
+ .name = "tegra_host1x",
+ .id = UCLASS_SIMPLE_BUS,
+ .of_match = tegra_host1x_ids,
+ .probe = tegra_host1x_probe,
+ .flags = DM_FLAG_PRE_RELOC,
+};