Recent Rockchip SoCs have a new hardware block called Native Interface
Unit (NIU), which gates clocks to devices behind them. These clock
gates will only have a running output clock when all of the following
conditions are met:
1. the parent clock is enabled
2. the enable bit is set correctly
3. the linked clock is enabled
To handle them this code registers them as a normal gate type clock,
which takes care of condition 1 + 2. The linked clock is handled by
using runtime PM clocks. Handling it via runtime PM requires setting
up a struct device for each of these clocks with a driver attached
to use the correct runtime PM operations. Thus the complete handling
of these clocks has been moved into its own driver.
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
---
drivers/clk/rockchip/Makefile | 1 +
drivers/clk/rockchip/clk-rk3588.c | 23 +--------
drivers/clk/rockchip/clk.c | 52 +++++++++++++++++++
drivers/clk/rockchip/clk.h | 25 +++++++++
drivers/clk/rockchip/gate-link.c | 85 +++++++++++++++++++++++++++++++
5 files changed, 165 insertions(+), 21 deletions(-)
create mode 100644 drivers/clk/rockchip/gate-link.c
diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
index af2ade54a7ef..3fe7616f0ebe 100644
--- a/drivers/clk/rockchip/Makefile
+++ b/drivers/clk/rockchip/Makefile
@@ -13,6 +13,7 @@ clk-rockchip-y += clk-inverter.o
clk-rockchip-y += clk-mmc-phase.o
clk-rockchip-y += clk-muxgrf.o
clk-rockchip-y += clk-ddr.o
+clk-rockchip-y += gate-link.o
clk-rockchip-$(CONFIG_RESET_CONTROLLER) += softrst.o
obj-$(CONFIG_CLK_PX30) += clk-px30.o
diff --git a/drivers/clk/rockchip/clk-rk3588.c b/drivers/clk/rockchip/clk-rk3588.c
index 618bda0be5a4..d76ab27dd1b8 100644
--- a/drivers/clk/rockchip/clk-rk3588.c
+++ b/drivers/clk/rockchip/clk-rk3588.c
@@ -12,25 +12,6 @@
#include <dt-bindings/clock/rockchip,rk3588-cru.h>
#include "clk.h"
-/*
- * Recent Rockchip SoCs have a new hardware block called Native Interface
- * Unit (NIU), which gates clocks to devices behind them. These effectively
- * need two parent clocks.
- *
- * Downstream enables the linked clock via runtime PM whenever the gate is
- * enabled. This implementation uses separate clock nodes for each of the
- * linked gate clocks, which leaks parts of the clock tree into DT.
- *
- * The GATE_LINK macro instead takes the second parent via 'linkname', but
- * ignores the information. Once the clock framework is ready to handle it, the
- * information should be passed on here. But since these clocks are required to
- * access multiple relevant IP blocks, such as PCIe or USB, we mark all linked
- * clocks critical until a better solution is available. This will waste some
- * power, but avoids leaking implementation details into DT or hanging the
- * system.
- */
-#define GATE_LINK(_id, cname, pname, linkedclk, f, o, b, gf) \
- GATE(_id, cname, pname, f, o, b, gf)
#define RK3588_LINKED_CLK CLK_IS_CRITICAL
@@ -2513,8 +2494,8 @@ static int clk_rk3588_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
- rockchip_clk_register_branches(ctx, rk3588_clk_branches,
- ARRAY_SIZE(rk3588_clk_branches));
+ rockchip_clk_register_late_branches(dev, ctx, rk3588_clk_branches,
+ ARRAY_SIZE(rk3588_clk_branches));
rockchip_clk_finalize(ctx);
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index b87ca1e8c540..f0d76d62382c 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -19,6 +19,7 @@
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reboot.h>
@@ -467,6 +468,29 @@ unsigned long rockchip_clk_find_max_clk_id(struct rockchip_clk_branch *list,
}
EXPORT_SYMBOL_GPL(rockchip_clk_find_max_clk_id);
+static struct platform_device *rockchip_clk_register_gate_link(
+ struct device *parent_dev,
+ struct rockchip_clk_provider *ctx,
+ struct rockchip_clk_branch *clkbr)
+{
+ struct rockchip_gate_link_platdata gate_link_pdata = {
+ .ctx = ctx,
+ .clkbr = clkbr,
+ };
+
+ struct platform_device_info pdevinfo = {
+ .parent = parent_dev,
+ .name = "rockchip-gate-link-clk",
+ .id = clkbr->id,
+ .fwnode = dev_fwnode(parent_dev),
+ .of_node_reused = true,
+ .data = &gate_link_pdata,
+ .size_data = sizeof(gate_link_pdata),
+ };
+
+ return platform_device_register_full(&pdevinfo);
+}
+
void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
struct rockchip_clk_branch *list,
unsigned int nr_clk)
@@ -592,6 +616,9 @@ void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
list->div_width, list->div_flags,
ctx->reg_base, &ctx->lock);
break;
+ case branch_linked_gate:
+ /* must be registered late, fall-through for error message */
+ break;
}
/* none of the cases above matched */
@@ -612,6 +639,31 @@ void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
}
EXPORT_SYMBOL_GPL(rockchip_clk_register_branches);
+void rockchip_clk_register_late_branches(struct device *dev,
+ struct rockchip_clk_provider *ctx,
+ struct rockchip_clk_branch *list,
+ unsigned int nr_clk)
+{
+ unsigned int idx;
+
+ for (idx = 0; idx < nr_clk; idx++, list++) {
+ struct platform_device *pdev = NULL;
+
+ switch (list->branch_type) {
+ case branch_linked_gate:
+ pdev = rockchip_clk_register_gate_link(dev, ctx, list);
+ break;
+ default:
+ dev_err(dev, "unknown clock type %d\n", list->branch_type);
+ break;
+ }
+
+ if (!pdev)
+ dev_err(dev, "failed to register device for clock %s\n", list->name);
+ }
+}
+EXPORT_SYMBOL_GPL(rockchip_clk_register_late_branches);
+
void rockchip_clk_register_armclk(struct rockchip_clk_provider *ctx,
unsigned int lookup_id,
const char *name, const char *const *parent_names,
diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index d9e071ca9c5d..9b37d44b9e5d 100644
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -570,6 +570,7 @@ enum rockchip_clk_branch_type {
branch_divider,
branch_fraction_divider,
branch_gate,
+ branch_linked_gate,
branch_mmc,
branch_inverter,
branch_factor,
@@ -597,6 +598,7 @@ struct rockchip_clk_branch {
int gate_offset;
u8 gate_shift;
u8 gate_flags;
+ unsigned int linked_clk_id;
struct rockchip_clk_branch *child;
};
@@ -895,6 +897,20 @@ struct rockchip_clk_branch {
.gate_flags = gf, \
}
+#define GATE_LINK(_id, cname, pname, linkedclk, f, o, b, gf) \
+ { \
+ .id = _id, \
+ .branch_type = branch_linked_gate, \
+ .name = cname, \
+ .parent_names = (const char *[]){ pname }, \
+ .linked_clk_id = linkedclk, \
+ .num_parents = 1, \
+ .flags = f, \
+ .gate_offset = o, \
+ .gate_shift = b, \
+ .gate_flags = gf, \
+ }
+
#define MMC(_id, cname, pname, offset, shift) \
{ \
.id = _id, \
@@ -1034,6 +1050,11 @@ static inline void rockchip_clk_set_lookup(struct rockchip_clk_provider *ctx,
ctx->clk_data.clks[id] = clk;
}
+struct rockchip_gate_link_platdata {
+ struct rockchip_clk_provider *ctx;
+ struct rockchip_clk_branch *clkbr;
+};
+
struct rockchip_clk_provider *rockchip_clk_init(struct device_node *np,
void __iomem *base, unsigned long nr_clks);
struct rockchip_clk_provider *rockchip_clk_init_early(struct device_node *np,
@@ -1046,6 +1067,10 @@ unsigned long rockchip_clk_find_max_clk_id(struct rockchip_clk_branch *list,
void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
struct rockchip_clk_branch *list,
unsigned int nr_clk);
+void rockchip_clk_register_late_branches(struct device *dev,
+ struct rockchip_clk_provider *ctx,
+ struct rockchip_clk_branch *list,
+ unsigned int nr_clk);
void rockchip_clk_register_plls(struct rockchip_clk_provider *ctx,
struct rockchip_pll_clock *pll_list,
unsigned int nr_pll, int grf_lock_offset);
diff --git a/drivers/clk/rockchip/gate-link.c b/drivers/clk/rockchip/gate-link.c
new file mode 100644
index 000000000000..cd0f7a2d30ab
--- /dev/null
+++ b/drivers/clk/rockchip/gate-link.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024 Collabora Ltd.
+ * Author: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include "clk.h"
+
+static int rk_clk_gate_link_register(struct device *dev,
+ struct rockchip_clk_provider *ctx,
+ struct rockchip_clk_branch *clkbr)
+{
+ unsigned long flags = clkbr->flags | CLK_SET_RATE_PARENT;
+ struct clk *clk;
+
+ clk = clk_register_gate(dev, clkbr->name, clkbr->parent_names[0],
+ flags, ctx->reg_base + clkbr->gate_offset,
+ clkbr->gate_shift, clkbr->gate_flags,
+ &ctx->lock);
+
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ rockchip_clk_set_lookup(ctx, clk, clkbr->id);
+ return 0;
+}
+
+static int rk_clk_gate_link_probe(struct platform_device *pdev)
+{
+ struct rockchip_gate_link_platdata *pdata;
+ struct device *dev = &pdev->dev;
+ struct clk *linked_clk;
+ int ret;
+
+ pdata = dev_get_platdata(dev);
+ if (!pdata)
+ return dev_err_probe(dev, -ENODEV, "missing platform data");
+
+ ret = devm_pm_runtime_enable(dev);
+ if (ret)
+ return ret;
+
+ ret = devm_pm_clk_create(dev);
+ if (ret)
+ return ret;
+
+ linked_clk = rockchip_clk_get_lookup(pdata->ctx, pdata->clkbr->linked_clk_id);
+ ret = pm_clk_add_clk(dev, linked_clk);
+ if (ret)
+ return ret;
+
+ ret = rk_clk_gate_link_register(dev, pdata->ctx, pdata->clkbr);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ pm_clk_remove_clk(dev, linked_clk);
+ return ret;
+}
+
+static const struct dev_pm_ops rk_clk_gate_link_pm_ops = {
+ SET_RUNTIME_PM_OPS(pm_clk_suspend, pm_clk_resume, NULL)
+};
+
+static struct platform_driver rk_clk_gate_link_driver = {
+ .probe = rk_clk_gate_link_probe,
+ .driver = {
+ .name = "rockchip-gate-link-clk",
+ .pm = &rk_clk_gate_link_pm_ops,
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int __init rk_clk_gate_link_drv_register(void)
+{
+ return platform_driver_register(&rk_clk_gate_link_driver);
+}
+core_initcall(rk_clk_gate_link_drv_register);
--
2.45.2
