[PATCH v2 0/7] ARM: Rockchip: add cpuclk handling - clock-tree part

[PATCH v2 0/7] ARM: Rockchip: add cpuclk handling - clock-tree part

[Heiko Stuebner]

This series implements cpu frequency-scaling for Rockchip SoCs.
The whole handling of the armclk frequency changes and therefore
the implementention is very similar to the recent series for
Samsung SoCs from Thomas Abraham.

Tested on a
- rk3066 Marsboard
- rk3188 Radxa Rock
- rk3288 Evaluation board

This is the part that would go through the clock tree and the patches
are build against current clk-next.

On the arm-soc side we would need the ARMCLK id in an exported branch
from the clk tree so that the devicetree changes can use this new id.

The series also is split, as clk-next and the arm-soc parts have diverged
so much, that it's not possible to create one series against one tree
and stay sane.

changes since v1:
- address comments received concerning smaller issues
- split series into two, one for clk-next and one for arm-soc

Heiko Stuebner (6):
  clk: rockchip: fix rk3066 pll status register location
  clk: rockchip: reparent aclk_cpu_pre to the gpll
  clk: rockchip: make tightly bound armclk child-clocks read-only
  clk: rockchip: add new clock-type for the cpuclk
  clk: rockchip: add binding id for ARMCLK
  clk: rockchip: switch to using the new cpuclk type for armclk

Jianqun (1):
  clk: rockchip: fix rk3288 pll status register location

 drivers/clk/rockchip/Makefile                 |   1 +
 drivers/clk/rockchip/clk-cpu.c                | 316 ++++++++++++++++++++++++++
 drivers/clk/rockchip/clk-rk3188.c             | 161 +++++++++++--
 drivers/clk/rockchip/clk-rk3288.c             |  93 ++++++--
 drivers/clk/rockchip/clk.c                    |  20 ++
 drivers/clk/rockchip/clk.h                    |  36 +++
 include/dt-bindings/clock/rk3188-cru-common.h |   1 +
 include/dt-bindings/clock/rk3288-cru.h        |   1 +
 8 files changed, 601 insertions(+), 28 deletions(-)
 create mode 100644 drivers/clk/rockchip/clk-cpu.c

-- 
2.0.1

[PATCH v2 1/7] clk: rockchip: fix rk3066 pll status register location

[Heiko Stuebner]

The register providing the pll lock status is at a different address on the
rk3066. The error became apparent while working on cpufreq support for
the rockchip SoCs.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/clk-rk3188.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/rockchip/clk-rk3188.c b/drivers/clk/rockchip/clk-rk3188.c
index 0147614..1c5e644 100644
--- a/drivers/clk/rockchip/clk-rk3188.c
+++ b/drivers/clk/rockchip/clk-rk3188.c
@@ -19,6 +19,7 @@
 #include <dt-bindings/clock/rk3188-cru-common.h>
 #include "clk.h"
 
+#define RK3066_GRF_SOC_STATUS	0x15c
 #define RK3188_GRF_SOC_STATUS	0xac
 
 enum rk3188_plls {
@@ -629,9 +630,6 @@ static void __init rk3188_common_clk_init(struct device_node *np)
 		pr_warn("%s: could not register clock usb480m: %ld\n",
 			__func__, PTR_ERR(clk));
 
-	rockchip_clk_register_plls(rk3188_pll_clks,
-				   ARRAY_SIZE(rk3188_pll_clks),
-				   RK3188_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(common_clk_branches,
 				  ARRAY_SIZE(common_clk_branches));
 	rockchip_clk_protect_critical(rk3188_critical_clocks,
@@ -644,6 +642,9 @@ static void __init rk3188_common_clk_init(struct device_node *np)
 static void __init rk3066a_clk_init(struct device_node *np)
 {
 	rk3188_common_clk_init(np);
+	rockchip_clk_register_plls(rk3188_pll_clks,
+				   ARRAY_SIZE(rk3188_pll_clks),
+				   RK3066_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(rk3066a_clk_branches,
 				  ARRAY_SIZE(rk3066a_clk_branches));
 }
@@ -652,6 +653,9 @@ CLK_OF_DECLARE(rk3066a_cru, "rockchip,rk3066a-cru", rk3066a_clk_init);
 static void __init rk3188a_clk_init(struct device_node *np)
 {
 	rk3188_common_clk_init(np);
+	rockchip_clk_register_plls(rk3188_pll_clks,
+				   ARRAY_SIZE(rk3188_pll_clks),
+				   RK3188_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(rk3188_clk_branches,
 				  ARRAY_SIZE(rk3188_clk_branches));
 }
-- 
2.0.1

[PATCH v2 2/7] clk: rockchip: fix rk3288 pll status register location

[Heiko Stuebner]

From: Jianqun <jay.xu@rock-chips.com>

In RK3288, APLL lock status bit is in GRF_SOC_STATUS1,
but in RK3188, is GRFSOC_STATUS0.

Signed-off-by: Jianqun <jay.xu@rock-chips.com>

Also name the constant accordingly as GRF_SOC_STATUS1
to prevent confusion.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/clk-rk3288.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
index 08c24c6..b023425 100644
--- a/drivers/clk/rockchip/clk-rk3288.c
+++ b/drivers/clk/rockchip/clk-rk3288.c
@@ -20,7 +20,7 @@
 #include "clk.h"
 
 #define RK3288_GRF_SOC_CON(x)	(0x244 + x * 4)
-#define RK3288_GRF_SOC_STATUS	0x280
+#define RK3288_GRF_SOC_STATUS1	0x284
 
 enum rk3288_plls {
 	apll, dpll, cpll, gpll, npll,
@@ -713,7 +713,7 @@ static void __init rk3288_clk_init(struct device_node *np)
 
 	rockchip_clk_register_plls(rk3288_pll_clks,
 				   ARRAY_SIZE(rk3288_pll_clks),
-				   RK3288_GRF_SOC_STATUS);
+				   RK3288_GRF_SOC_STATUS1);
 	rockchip_clk_register_branches(rk3288_clk_branches,
 				  ARRAY_SIZE(rk3288_clk_branches));
 	rockchip_clk_protect_critical(rk3288_critical_clocks,
-- 
2.0.1

[PATCH v2 3/7] clk: rockchip: reparent aclk_cpu_pre to the gpll

[Heiko Stuebner]

aclk_cpu_pre on the rk3188 can either be sourced from the armclk or the gpll.
To reduce complexity on apll changes caused by cpufreq, reparent it always
to the gpll source.

If really necessary it could be reparented back on a per board level using
the assigned-clocks mechanism.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/clk-rk3188.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/clk/rockchip/clk-rk3188.c b/drivers/clk/rockchip/clk-rk3188.c
index 1c5e644..6a81bc9 100644
--- a/drivers/clk/rockchip/clk-rk3188.c
+++ b/drivers/clk/rockchip/clk-rk3188.c
@@ -652,12 +652,33 @@ CLK_OF_DECLARE(rk3066a_cru, "rockchip,rk3066a-cru", rk3066a_clk_init);
 
 static void __init rk3188a_clk_init(struct device_node *np)
 {
+	struct clk *clk1, *clk2;
+	unsigned long rate;
+	int ret;
+
 	rk3188_common_clk_init(np);
 	rockchip_clk_register_plls(rk3188_pll_clks,
 				   ARRAY_SIZE(rk3188_pll_clks),
 				   RK3188_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(rk3188_clk_branches,
 				  ARRAY_SIZE(rk3188_clk_branches));
+
+	/* reparent aclk_cpu_pre from apll */
+	clk1 = __clk_lookup("aclk_cpu_pre");
+	clk2 = __clk_lookup("gpll");
+	if (clk1 && clk2) {
+		rate = clk_get_rate(clk1);
+
+		ret = clk_set_parent(clk1, clk2);
+		if (ret < 0)
+			pr_warn("%s: could not reparent aclk_cpu_pre to gpll\n",
+				__func__);
+
+		clk_set_rate(clk1, rate);
+	} else {
+		pr_warn("%s: missing clocks to reparent aclk_cpu_pre to gpll\n",
+			__func__);
+	}
 }
 CLK_OF_DECLARE(rk3188a_cru, "rockchip,rk3188a-cru", rk3188a_clk_init);
 
-- 
2.0.1

[PATCH v2 4/7] clk: rockchip: make tightly bound armclk child-clocks read-only

[Heiko Stuebner]

Rockchip SoCs contain clocks tightly bound to the armclk, where the best
rate / divider is supplied by the vendor after careful measuring.
Often this ideal rate may be greater than the current rate.

Therefore prevent the ccf from trying to set these dividers itself by
setting them to read-only.

In the case of the rk3066, this also includes the aclk_cpu, which makes it
necessary to also split its direct child-clocks (pclk_cpu, hclk_cpu, ...)
into individual definitions for rk3066 and rk3188.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/clk-rk3188.c | 26 ++++++++++++++++++--------
 drivers/clk/rockchip/clk-rk3288.c | 18 +++++++++---------
 2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/drivers/clk/rockchip/clk-rk3188.c b/drivers/clk/rockchip/clk-rk3188.c
index 6a81bc9..adfbfef 100644
--- a/drivers/clk/rockchip/clk-rk3188.c
+++ b/drivers/clk/rockchip/clk-rk3188.c
@@ -174,17 +174,10 @@ static struct rockchip_clk_branch common_clk_branches[] __initdata = {
 	GATE(0, "aclk_cpu", "aclk_cpu_pre", 0,
 			RK2928_CLKGATE_CON(0), 3, GFLAGS),
 
-	DIV(0, "pclk_cpu_pre", "aclk_cpu_pre", 0,
-			RK2928_CLKSEL_CON(1), 12, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO),
 	GATE(0, "atclk_cpu", "pclk_cpu_pre", 0,
 			RK2928_CLKGATE_CON(0), 6, GFLAGS),
 	GATE(0, "pclk_cpu", "pclk_cpu_pre", 0,
 			RK2928_CLKGATE_CON(0), 5, GFLAGS),
-	DIV(0, "hclk_cpu_pre", "aclk_cpu_pre", 0,
-			RK2928_CLKSEL_CON(1), 8, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO),
-	COMPOSITE_NOMUX(0, "hclk_ahb2apb", "hclk_cpu_pre", 0,
-			RK2928_CLKSEL_CON(1), 14, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO,
-			RK2928_CLKGATE_CON(4), 9, GFLAGS),
 	GATE(0, "hclk_cpu", "hclk_cpu_pre", 0,
 			RK2928_CLKGATE_CON(0), 4, GFLAGS),
 
@@ -416,7 +409,17 @@ static struct rockchip_clk_branch rk3066a_clk_branches[] __initdata = {
 	COMPOSITE_NOGATE(0, "armclk", mux_armclk_p, 0,
 			RK2928_CLKSEL_CON(0), 8, 1, MFLAGS, 0, 5, DFLAGS),
 	DIVTBL(0, "aclk_cpu_pre", "armclk", 0,
-			RK2928_CLKSEL_CON(1), 0, 3, DFLAGS, div_aclk_cpu_t),
+			RK2928_CLKSEL_CON(1), 0, 3, DFLAGS | CLK_DIVIDER_READ_ONLY, div_aclk_cpu_t),
+	DIV(0, "pclk_cpu_pre", "aclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 12, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO
+							    | CLK_DIVIDER_READ_ONLY),
+	DIV(0, "hclk_cpu_pre", "aclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 8, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO
+							   | CLK_DIVIDER_READ_ONLY),
+	COMPOSITE_NOMUX(0, "hclk_ahb2apb", "hclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 14, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO
+							    | CLK_DIVIDER_READ_ONLY,
+			RK2928_CLKGATE_CON(4), 9, GFLAGS),
 
 	GATE(CORE_L2C, "core_l2c", "aclk_cpu", 0,
 			RK2928_CLKGATE_CON(9), 4, GFLAGS),
@@ -534,6 +537,13 @@ static struct rockchip_clk_branch rk3188_clk_branches[] __initdata = {
 	/* do not source aclk_cpu_pre from the apll, to keep complexity down */
 	COMPOSITE_NOGATE(0, "aclk_cpu_pre", mux_aclk_cpu_p, CLK_SET_RATE_NO_REPARENT,
 			RK2928_CLKSEL_CON(0), 5, 1, MFLAGS, 0, 5, DFLAGS),
+	DIV(0, "pclk_cpu_pre", "aclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 12, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO),
+	DIV(0, "hclk_cpu_pre", "aclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 8, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO),
+	COMPOSITE_NOMUX(0, "hclk_ahb2apb", "hclk_cpu_pre", 0,
+			RK2928_CLKSEL_CON(1), 14, 2, DFLAGS | CLK_DIVIDER_POWER_OF_TWO,
+			RK2928_CLKGATE_CON(4), 9, GFLAGS),
 
 	GATE(CORE_L2C, "core_l2c", "armclk", 0,
 			RK2928_CLKGATE_CON(9), 4, GFLAGS),
diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
index b023425..2b23719 100644
--- a/drivers/clk/rockchip/clk-rk3288.c
+++ b/drivers/clk/rockchip/clk-rk3288.c
@@ -170,31 +170,31 @@ static struct rockchip_clk_branch rk3288_clk_branches[] __initdata = {
 			RK3288_CLKSEL_CON(0), 15, 1, MFLAGS, 8, 5, DFLAGS),
 
 	COMPOSITE_NOMUX(0, "armcore0", "armclk", 0,
-			RK3288_CLKSEL_CON(36), 0, 3, DFLAGS,
+			RK3288_CLKSEL_CON(36), 0, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 0, GFLAGS),
 	COMPOSITE_NOMUX(0, "armcore1", "armclk", 0,
-			RK3288_CLKSEL_CON(36), 4, 3, DFLAGS,
+			RK3288_CLKSEL_CON(36), 4, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 1, GFLAGS),
 	COMPOSITE_NOMUX(0, "armcore2", "armclk", 0,
-			RK3288_CLKSEL_CON(36), 8, 3, DFLAGS,
+			RK3288_CLKSEL_CON(36), 8, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 2, GFLAGS),
 	COMPOSITE_NOMUX(0, "armcore3", "armclk", 0,
-			RK3288_CLKSEL_CON(36), 12, 3, DFLAGS,
+			RK3288_CLKSEL_CON(36), 12, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 3, GFLAGS),
 	COMPOSITE_NOMUX(0, "l2ram", "armclk", 0,
-			RK3288_CLKSEL_CON(37), 0, 3, DFLAGS,
+			RK3288_CLKSEL_CON(37), 0, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 4, GFLAGS),
 	COMPOSITE_NOMUX(0, "aclk_core_m0", "armclk", 0,
-			RK3288_CLKSEL_CON(0), 0, 4, DFLAGS,
+			RK3288_CLKSEL_CON(0), 0, 4, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 5, GFLAGS),
 	COMPOSITE_NOMUX(0, "aclk_core_mp", "armclk", 0,
-			RK3288_CLKSEL_CON(0), 4, 4, DFLAGS,
+			RK3288_CLKSEL_CON(0), 4, 4, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 6, GFLAGS),
 	COMPOSITE_NOMUX(0, "atclk", "armclk", 0,
-			RK3288_CLKSEL_CON(37), 4, 5, DFLAGS,
+			RK3288_CLKSEL_CON(37), 4, 5, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 7, GFLAGS),
 	COMPOSITE_NOMUX(0, "pclk_dbg_pre", "armclk", 0,
-			RK3288_CLKSEL_CON(37), 9, 5, DFLAGS,
+			RK3288_CLKSEL_CON(37), 9, 5, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			RK3288_CLKGATE_CON(12), 8, GFLAGS),
 	GATE(0, "pclk_dbg", "pclk_dbg_pre", 0,
 			RK3288_CLKGATE_CON(12), 9, GFLAGS),
-- 
2.0.1

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Heiko Stuebner]

When changing the armclk on Rockchip SoCs it is supposed to be reparented
to an alternate parent before changing the underlying pll and back after
the change. Additionally there exist clocks that are very tightly bound to
the armclk whose divider values are set according to the armclk rate.

Add a special clock-type to handle all that. The rate table and divider
values will be supplied from the soc-specific clock controllers.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/Makefile  |   1 +
 drivers/clk/rockchip/clk-cpu.c | 316 +++++++++++++++++++++++++++++++++++++++++
 drivers/clk/rockchip/clk.c     |  20 +++
 drivers/clk/rockchip/clk.h     |  36 +++++
 4 files changed, 373 insertions(+)
 create mode 100644 drivers/clk/rockchip/clk-cpu.c

diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
index ee6b077..bd8514d 100644
--- a/drivers/clk/rockchip/Makefile
+++ b/drivers/clk/rockchip/Makefile
@@ -5,6 +5,7 @@
 obj-y	+= clk-rockchip.o
 obj-y	+= clk.o
 obj-y	+= clk-pll.o
+obj-y	+= clk-cpu.o
 obj-$(CONFIG_RESET_CONTROLLER)	+= softrst.o
 
 obj-y	+= clk-rk3188.o
diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
new file mode 100644
index 0000000..b8382b1
--- /dev/null
+++ b/drivers/clk/rockchip/clk-cpu.c
@@ -0,0 +1,316 @@
+/*
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * based on clk/samsung/clk-cpu.c
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This file contains the utility function to register CPU clock for Samsung
+ * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a
+ * group of CPUs. The CPU clock is typically derived from a hierarchy of clock
+ * blocks which includes mux and divider blocks. There are a number of other
+ * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI
+ * clock for CPU domain. The rates of these auxiliary clocks are related to the
+ * CPU clock rate and this relation is usually specified in the hardware manual
+ * of the SoC or supplied after the SoC characterization.
+ *
+ * The below implementation of the CPU clock allows the rate changes of the CPU
+ * clock and the corresponding rate changes of the auxillary clocks of the CPU
+ * domain. The platform clock driver provides a clock register configuration
+ * for each configurable rate which is then used to program the clock hardware
+ * registers to acheive a fast co-oridinated rate change for all the CPU domain
+ * clocks.
+ *
+ * On a rate change request for the CPU clock, the rate change is propagated
+ * upto the PLL supplying the clock to the CPU domain clock blocks. While the
+ * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an
+ * alternate clock source. If required, the alternate clock source is divided
+ * down in order to keep the output clock rate within the previous OPP limits.
+ */
+
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+#include "clk.h"
+
+/**
+ * struct rockchip_cpuclk: information about clock supplied to a CPU core.
+ * @hw:		handle between ccf and cpu clock.
+ * @alt_parent:	alternate parent clock to use when switching the speed
+ *		of the primary parent clock.
+ * @reg_base:	base register for cpu-clock values.
+ * @clk_nb:	clock notifier registered for changes in clock speed of the
+ *		primary parent clock.
+ * @rate_count:	number of rates in the rate_table
+ * @rate_table:	pll-rates and their associated dividers
+ * @reg_data:	cpu-specific register settings
+ * @lock:	clock lock
+ */
+struct rockchip_cpuclk {
+	struct clk_hw				hw;
+
+	struct clk_mux				cpu_mux;
+	const struct clk_ops			*cpu_mux_ops;
+
+	struct clk				*alt_parent;
+	void __iomem				*reg_base;
+	struct notifier_block			clk_nb;
+	unsigned int				rate_count;
+	struct rockchip_cpuclk_rate_table	*rate_table;
+	const struct rockchip_cpuclk_reg_data	*reg_data;
+	spinlock_t				*lock;
+};
+
+#define to_rockchip_cpuclk_hw(hw) container_of(hw, struct rockchip_cpuclk, hw)
+#define to_rockchip_cpuclk_nb(nb) \
+			container_of(nb, struct rockchip_cpuclk, clk_nb)
+
+static const struct rockchip_cpuclk_rate_table *rockchip_get_cpuclk_settings(
+			    struct rockchip_cpuclk *cpuclk, unsigned long rate)
+{
+	const struct rockchip_cpuclk_rate_table *rate_table =
+							cpuclk->rate_table;
+	int i;
+
+	for (i = 0; i < cpuclk->rate_count; i++) {
+		if (rate == rate_table[i].prate)
+			return &rate_table[i];
+	}
+
+	return NULL;
+}
+
+static unsigned long rockchip_cpuclk_recalc_rate(struct clk_hw *hw,
+					unsigned long parent_rate)
+{
+	struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_hw(hw);
+	const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+	u32 clksel0 = readl_relaxed(cpuclk->reg_base + reg_data->core_reg);
+
+	clksel0 >>= reg_data->div_core_shift;
+	clksel0 &= reg_data->div_core_mask;
+	return parent_rate / (clksel0 + 1);
+}
+
+static const struct clk_ops rockchip_cpuclk_ops = {
+	.recalc_rate = rockchip_cpuclk_recalc_rate,
+};
+
+static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
+					   struct clk_notifier_data *ndata)
+{
+	const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+	const struct rockchip_cpuclk_rate_table *rate;
+	unsigned long alt_prate, alt_div;
+	int i;
+
+	rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
+	if (!rate) {
+		pr_err("%s: Invalid rate : %lu for cpuclk\n",
+		       __func__, ndata->new_rate);
+		return -EINVAL;
+	}
+
+	alt_prate = clk_get_rate(cpuclk->alt_parent);
+
+	spin_lock(cpuclk->lock);
+
+	/*
+	 * If the old parent clock speed is less than the clock speed
+	 * of the alternate parent, then it should be ensured that at no point
+	 * the armclk speed is more than the old_rate until the dividers are
+	 * set.
+	 */
+	if (alt_prate > ndata->old_rate) {
+		alt_div =  DIV_ROUND_UP(alt_prate, ndata->old_rate) - 1;
+		if (alt_div > reg_data->div_core_mask) {
+			pr_warn("%s: limiting alt-divider %lu to %d\n",
+				__func__, alt_div, reg_data->div_core_mask);
+			alt_div = reg_data->div_core_mask;
+		}
+
+		pr_debug("%s: setting div %lu as alt-rate %lu > old-rate %lu\n",
+			 __func__, alt_div, alt_prate, ndata->old_rate);
+		writel_relaxed(HIWORD_UPDATE(alt_div,
+					     reg_data->div_core_mask,
+					     reg_data->div_core_shift),
+			      cpuclk->reg_base + reg_data->core_reg);
+	}
+
+	/* select alternate parent */
+	writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
+	       cpuclk->reg_base + reg_data->core_reg);
+
+	/* alternate parent is active now. set the dividers */
+	for (i = 0; i < ARRAY_SIZE(rate->divs); i++) {
+		const struct rockchip_cpuclk_clksel *clksel = &rate->divs[i];
+
+		if (!clksel->reg)
+			continue;
+
+		pr_debug("%s: setting reg 0x%x to 0x%x\n",
+			 __func__, clksel->reg, clksel->val);
+		writel(clksel->val , cpuclk->reg_base + clksel->reg);
+	}
+
+	spin_unlock(cpuclk->lock);
+	return 0;
+}
+
+static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
+					    struct clk_notifier_data *ndata)
+{
+	const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+
+	spin_lock(cpuclk->lock);
+
+	/* post-rate change event, re-mux back to primary parent */
+	writel(HIWORD_UPDATE(0, 1, reg_data->mux_core_shift),
+	       cpuclk->reg_base + reg_data->core_reg);
+
+	/* remove any core dividers */
+	writel(HIWORD_UPDATE(0, reg_data->div_core_mask,
+			     reg_data->div_core_shift),
+	       cpuclk->reg_base + reg_data->core_reg);
+
+	spin_unlock(cpuclk->lock);
+	return 0;
+}
+
+/*
+ * This clock notifier is called when the frequency of the parent clock
+ * of cpuclk is to be changed. This notifier handles the setting up all
+ * the divider clocks, remux to temporary parent and handling the safe
+ * frequency levels when using temporary parent.
+ */
+static int rockchip_cpuclk_notifier_cb(struct notifier_block *nb,
+					unsigned long event, void *data)
+{
+	struct clk_notifier_data *ndata = data;
+	struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_nb(nb);
+	int ret = 0;
+
+	pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
+		 __func__, event, ndata->old_rate, ndata->new_rate);
+	if (event == PRE_RATE_CHANGE)
+		ret = rockchip_cpuclk_pre_rate_change(cpuclk, ndata);
+	else if (event == POST_RATE_CHANGE)
+		ret = rockchip_cpuclk_post_rate_change(cpuclk, ndata);
+
+	return notifier_from_errno(ret);
+}
+
+struct clk *rockchip_clk_register_cpuclk(const char *name,
+			const char **parent_names, u8 num_parents,
+			const struct rockchip_cpuclk_reg_data *reg_data,
+			struct rockchip_cpuclk_rate_table *rate_table,
+			void __iomem *reg_base, spinlock_t *lock)
+{
+	struct rockchip_cpuclk *cpuclk;
+	struct clk_init_data init;
+	struct clk *clk, *cclk;
+	int ret;
+
+	if (!reg_data) {
+		pr_err("%s: no soc register information\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (num_parents != 2) {
+		pr_err("%s: needs two parent clocks\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
+	if (!cpuclk)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.parent_names = &parent_names[0];
+	init.num_parents = 1;
+	init.ops = &rockchip_cpuclk_ops;
+
+	/* only allow rate changes when we have a rate table */
+	init.flags = rate_table ? CLK_SET_RATE_PARENT : 0;
+
+	/* disallow automatic parent changes by ccf */
+	init.flags |= CLK_SET_RATE_NO_REPARENT;
+
+	cpuclk->reg_base = reg_base;
+	cpuclk->lock = lock;
+	cpuclk->reg_data = reg_data;
+	cpuclk->clk_nb.notifier_call = rockchip_cpuclk_notifier_cb;
+	cpuclk->hw.init = &init;
+
+	cpuclk->alt_parent = __clk_lookup(parent_names[1]);
+	if (!cpuclk->alt_parent) {
+		pr_err("%s: could not lookup alternate parent\n",
+		       __func__);
+		ret = -EINVAL;
+		goto free_cpuclk;
+	}
+
+	ret = clk_prepare_enable(cpuclk->alt_parent);
+	if (ret) {
+		pr_err("%s: could not enable alternate parent\n",
+		       __func__);
+		goto free_cpuclk;
+	}
+
+	clk = __clk_lookup(parent_names[0]);
+	if (!clk) {
+		pr_err("%s: could not lookup parent clock %s\n",
+		       __func__, parent_names[0]);
+		ret = -EINVAL;
+		goto free_cpuclk;
+	}
+
+	ret = clk_notifier_register(clk, &cpuclk->clk_nb);
+	if (ret) {
+		pr_err("%s: failed to register clock notifier for %s\n",
+				__func__, name);
+		goto free_cpuclk;
+	}
+
+	if (rate_table) {
+		int nrates;
+
+		/* find count of rates in rate_table */
+		for (nrates = 0; rate_table[nrates].prate != 0; )
+			nrates++;
+
+		cpuclk->rate_count = nrates;
+		cpuclk->rate_table = kmemdup(rate_table,
+					     sizeof(*rate_table) * nrates,
+					     GFP_KERNEL);
+		if (!cpuclk->rate_table) {
+			pr_err("%s: could not allocate memory for cpuclk rates\n",
+			       __func__);
+			ret = -ENOMEM;
+			goto unregister_notifier;
+		}
+	}
+
+	cclk = clk_register(NULL, &cpuclk->hw);
+	if (IS_ERR(clk)) {
+		pr_err("%s: could not register cpuclk %s\n", __func__,	name);
+		ret = PTR_ERR(clk);
+		goto free_rate_table;
+	}
+
+	return cclk;
+
+free_rate_table:
+	kfree(cpuclk->rate_table);
+unregister_notifier:
+	clk_notifier_unregister(clk, &cpuclk->clk_nb);
+free_cpuclk:
+	kfree(cpuclk);
+	return ERR_PTR(ret);
+}
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index d9c6db2..f87ac4a 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -297,6 +297,26 @@ void __init rockchip_clk_register_branches(
 	}
 }
 
+void __init rockchip_clk_register_armclk(unsigned int lookup_id,
+			const char *name, const char **parent_names,
+			u8 num_parents,
+			const struct rockchip_cpuclk_reg_data *reg_data,
+			struct rockchip_cpuclk_rate_table *rate_table)
+{
+	struct clk *clk;
+
+	clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
+					   reg_data, rate_table, reg_base,
+					   &clk_lock);
+	if (IS_ERR(clk)) {
+		pr_err("%s: failed to register clock %s: %ld\n",
+		       __func__, name, PTR_ERR(clk));
+		return;
+	}
+
+	rockchip_clk_add_lookup(clk, lookup_id);
+}
+
 void __init rockchip_clk_protect_critical(const char *clocks[], int nclocks)
 {
 	int i;
diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index 2b0bca1..e0ea61e 100644
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -120,6 +120,38 @@ struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
 		struct rockchip_pll_rate_table *rate_table,
 		spinlock_t *lock);
 
+struct rockchip_cpuclk_clksel {
+	int reg;
+	u32 val;
+};
+
+#define ROCKCHIP_CPUCLK_NUM_DIVIDERS	2
+struct rockchip_cpuclk_rate_table {
+	unsigned long prate;
+	struct rockchip_cpuclk_clksel divs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
+};
+
+/**
+ * struct rockchip_cpuclk_reg_data: describes register offsets and masks of the cpuclock
+ * @core_reg:		register offset of the core settings register
+ * @div_core_shift:	core divider offset used to divide the pll value
+ * @div_core_mask:	core divider mask
+ * @mux_core_shift:	offset of the core multiplexer
+ */
+struct rockchip_cpuclk_reg_data {
+	int		core_reg;
+	u8		div_core_shift;
+	u32		div_core_mask;
+	int		mux_core_reg;
+	u8		mux_core_shift;
+};
+
+struct clk *rockchip_clk_register_cpuclk(const char *name,
+			const char **parent_names, u8 num_parents,
+			const struct rockchip_cpuclk_reg_data *reg_data,
+			struct rockchip_cpuclk_rate_table *rate_table,
+			void __iomem *reg_base, spinlock_t *lock);
+
 #define PNAME(x) static const char *x[] __initconst
 
 enum rockchip_clk_branch_type {
@@ -329,6 +361,10 @@ void rockchip_clk_register_branches(struct rockchip_clk_branch *clk_list,
 				    unsigned int nr_clk);
 void rockchip_clk_register_plls(struct rockchip_pll_clock *pll_list,
 				unsigned int nr_pll, int grf_lock_offset);
+void rockchip_clk_register_armclk(unsigned int lookup_id, const char *name,
+			const char **parent_names, u8 num_parents,
+			const struct rockchip_cpuclk_reg_data *reg_data,
+			struct rockchip_cpuclk_rate_table *rate_table);
 void rockchip_clk_protect_critical(const char *clocks[], int nclocks);
 
 #define ROCKCHIP_SOFTRST_HIWORD_MASK	BIT(0)
-- 
2.0.1

[PATCH v2 6/7] clk: rockchip: add binding id for ARMCLK

[Heiko Stuebner]

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 include/dt-bindings/clock/rk3188-cru-common.h | 1 +
 include/dt-bindings/clock/rk3288-cru.h        | 1 +
 2 files changed, 2 insertions(+)

diff --git a/include/dt-bindings/clock/rk3188-cru-common.h b/include/dt-bindings/clock/rk3188-cru-common.h
index 750ee60..6a37050 100644
--- a/include/dt-bindings/clock/rk3188-cru-common.h
+++ b/include/dt-bindings/clock/rk3188-cru-common.h
@@ -20,6 +20,7 @@
 #define PLL_GPLL		4
 #define CORE_PERI		5
 #define CORE_L2C		6
+#define ARMCLK			7
 
 /* sclk gates (special clocks) */
 #define SCLK_UART0		64
diff --git a/include/dt-bindings/clock/rk3288-cru.h b/include/dt-bindings/clock/rk3288-cru.h
index ebcb460..8f75bf0 100644
--- a/include/dt-bindings/clock/rk3288-cru.h
+++ b/include/dt-bindings/clock/rk3288-cru.h
@@ -19,6 +19,7 @@
 #define PLL_CPLL		3
 #define PLL_GPLL		4
 #define PLL_NPLL		5
+#define ARMCLK			6
 
 /* sclk gates (special clocks) */
 #define SCLK_GPU		64
-- 
2.0.1

[PATCH v2 7/7] clk: rockchip: switch to using the new cpuclk type for armclk

[Heiko Stuebner]

This adds the necessary soc-specific divider values and switches the armclk
to use the newly introduced cpuclk type.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/clk/rockchip/clk-rk3188.c | 104 ++++++++++++++++++++++++++++++++++++--
 drivers/clk/rockchip/clk-rk3288.c |  71 +++++++++++++++++++++++++-
 2 files changed, 169 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/rockchip/clk-rk3188.c b/drivers/clk/rockchip/clk-rk3188.c
index adfbfef..db1a815 100644
--- a/drivers/clk/rockchip/clk-rk3188.c
+++ b/drivers/clk/rockchip/clk-rk3188.c
@@ -101,6 +101,100 @@ struct rockchip_pll_rate_table rk3188_pll_rates[] = {
 	{ /* sentinel */ },
 };
 
+#define RK3066_DIV_CORE_PERIPH_MASK	0x3
+#define RK3066_DIV_CORE_PERIPH_SHIFT	6
+#define RK3066_DIV_ACLK_CORE_MASK	0x7
+#define RK3066_DIV_ACLK_CORE_SHIFT	0
+#define RK3066_DIV_ACLK_HCLK_MASK	0x3
+#define RK3066_DIV_ACLK_HCLK_SHIFT	8
+#define RK3066_DIV_ACLK_PCLK_MASK	0x3
+#define RK3066_DIV_ACLK_PCLK_SHIFT	12
+#define RK3066_DIV_AHB2APB_MASK		0x3
+#define RK3066_DIV_AHB2APB_SHIFT	14
+
+#define RK3066_CLKSEL0(_core_peri)					\
+	{								\
+		.reg = RK2928_CLKSEL_CON(0),				\
+		.val = HIWORD_UPDATE(_core_peri, RK3066_DIV_CORE_PERIPH_MASK, \
+				RK3066_DIV_CORE_PERIPH_SHIFT)		\
+	}
+#define RK3066_CLKSEL1(_aclk_core, _aclk_hclk, _aclk_pclk, _ahb2apb)	\
+	{								\
+		.reg = RK2928_CLKSEL_CON(1),				\
+		.val = HIWORD_UPDATE(_aclk_core, RK3066_DIV_ACLK_CORE_MASK, \
+				RK3066_DIV_ACLK_CORE_SHIFT) |		\
+		       HIWORD_UPDATE(_aclk_hclk, RK3066_DIV_ACLK_HCLK_MASK, \
+				RK3066_DIV_ACLK_HCLK_SHIFT) |		\
+		       HIWORD_UPDATE(_aclk_pclk, RK3066_DIV_ACLK_PCLK_MASK, \
+				RK3066_DIV_ACLK_PCLK_SHIFT) |		\
+		       HIWORD_UPDATE(_ahb2apb, RK3066_DIV_AHB2APB_MASK,	\
+				RK3066_DIV_AHB2APB_SHIFT),		\
+	}
+
+#define RK3066_CPUCLK_RATE(_prate, _core_peri, _acore, _ahclk, _apclk, _h2p) \
+	{								\
+		.prate = _prate,					\
+		.divs = {						\
+			RK3066_CLKSEL0(_core_peri),			\
+			RK3066_CLKSEL1(_acore, _ahclk, _apclk, _h2p),	\
+		},							\
+	}
+
+static struct rockchip_cpuclk_rate_table rk3066_cpuclk_rates[] = {
+	RK3066_CPUCLK_RATE(1416000000, 2, 3, 1, 2, 1),
+	RK3066_CPUCLK_RATE(1200000000, 2, 3, 1, 2, 1),
+	RK3066_CPUCLK_RATE(1008000000, 2, 2, 1, 2, 1),
+	RK3066_CPUCLK_RATE( 816000000, 2, 2, 1, 2, 1),
+	RK3066_CPUCLK_RATE( 600000000, 1, 2, 1, 2, 1),
+	RK3066_CPUCLK_RATE( 504000000, 1, 1, 1, 2, 1),
+	RK3066_CPUCLK_RATE( 312000000, 0, 1, 1, 1, 0),
+	{ /* sentinel */ },
+};
+
+static const struct rockchip_cpuclk_reg_data rk3066_cpuclk_data = {
+	.core_reg = RK2928_CLKSEL_CON(0),
+	.div_core_shift = 0,
+	.div_core_mask = 0x1f,
+	.mux_core_shift = 8,
+};
+
+#define RK3188_DIV_ACLK_CORE_MASK	0x7
+#define RK3188_DIV_ACLK_CORE_SHIFT	3
+
+#define RK3188_CLKSEL1(_aclk_core)		\
+	{					\
+		.reg = RK2928_CLKSEL_CON(1),	\
+		.val = HIWORD_UPDATE(_aclk_core, RK3188_DIV_ACLK_CORE_MASK,\
+				 RK3188_DIV_ACLK_CORE_SHIFT) \
+	}
+#define RK3188_CPUCLK_RATE(_prate, _core_peri, _aclk_core)	\
+	{							\
+		.prate = _prate,				\
+		.divs = {					\
+			RK3066_CLKSEL0(_core_peri),		\
+			RK3188_CLKSEL1(_aclk_core),		\
+		},						\
+	}
+
+static struct rockchip_cpuclk_rate_table rk3188_cpuclk_rates[] = {
+	RK3188_CPUCLK_RATE(1608000000, 2, 3),
+	RK3188_CPUCLK_RATE(1416000000, 2, 3),
+	RK3188_CPUCLK_RATE(1200000000, 2, 3),
+	RK3188_CPUCLK_RATE(1008000000, 2, 3),
+	RK3188_CPUCLK_RATE( 816000000, 2, 3),
+	RK3188_CPUCLK_RATE( 600000000, 1, 3),
+	RK3188_CPUCLK_RATE( 504000000, 1, 3),
+	RK3188_CPUCLK_RATE( 312000000, 0, 1),
+	{ /* sentinel */ },
+};
+
+static const struct rockchip_cpuclk_reg_data rk3188_cpuclk_data = {
+	.core_reg = RK2928_CLKSEL_CON(0),
+	.div_core_shift = 9,
+	.div_core_mask = 0x1f,
+	.mux_core_shift = 8,
+};
+
 PNAME(mux_pll_p)		= { "xin24m", "xin32k" };
 PNAME(mux_armclk_p)		= { "apll", "gpll_armclk" };
 PNAME(mux_ddrphy_p)		= { "dpll", "gpll_ddr" };
@@ -406,8 +500,6 @@ static struct clk_div_table div_aclk_cpu_t[] = {
 };
 
 static struct rockchip_clk_branch rk3066a_clk_branches[] __initdata = {
-	COMPOSITE_NOGATE(0, "armclk", mux_armclk_p, 0,
-			RK2928_CLKSEL_CON(0), 8, 1, MFLAGS, 0, 5, DFLAGS),
 	DIVTBL(0, "aclk_cpu_pre", "armclk", 0,
 			RK2928_CLKSEL_CON(1), 0, 3, DFLAGS | CLK_DIVIDER_READ_ONLY, div_aclk_cpu_t),
 	DIV(0, "pclk_cpu_pre", "aclk_cpu_pre", 0,
@@ -528,8 +620,6 @@ PNAME(mux_hsicphy_p)		= { "sclk_otgphy0", "sclk_otgphy1",
 				    "gpll", "cpll" };
 
 static struct rockchip_clk_branch rk3188_clk_branches[] __initdata = {
-	COMPOSITE_NOGATE(0, "armclk", mux_armclk_p, 0,
-			RK2928_CLKSEL_CON(0), 8, 1, MFLAGS, 9, 5, DFLAGS),
 	COMPOSITE_NOMUX_DIVTBL(0, "aclk_core", "armclk", 0,
 			RK2928_CLKSEL_CON(1), 3, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
 			div_rk3188_aclk_core_t, RK2928_CLKGATE_CON(0), 7, GFLAGS),
@@ -657,6 +747,9 @@ static void __init rk3066a_clk_init(struct device_node *np)
 				   RK3066_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(rk3066a_clk_branches,
 				  ARRAY_SIZE(rk3066a_clk_branches));
+	rockchip_clk_register_armclk(ARMCLK, "armclk",
+			mux_armclk_p, ARRAY_SIZE(mux_armclk_p),
+			&rk3066_cpuclk_data, rk3066_cpuclk_rates);
 }
 CLK_OF_DECLARE(rk3066a_cru, "rockchip,rk3066a-cru", rk3066a_clk_init);
 
@@ -672,6 +765,9 @@ static void __init rk3188a_clk_init(struct device_node *np)
 				   RK3188_GRF_SOC_STATUS);
 	rockchip_clk_register_branches(rk3188_clk_branches,
 				  ARRAY_SIZE(rk3188_clk_branches));
+	rockchip_clk_register_armclk(ARMCLK, "armclk",
+				  mux_armclk_p, ARRAY_SIZE(mux_armclk_p),
+				  &rk3188_cpuclk_data, rk3188_cpuclk_rates);
 
 	/* reparent aclk_cpu_pre from apll */
 	clk1 = __clk_lookup("aclk_cpu_pre");
diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
index 2b23719..b019b3b 100644
--- a/drivers/clk/rockchip/clk-rk3288.c
+++ b/drivers/clk/rockchip/clk-rk3288.c
@@ -101,6 +101,71 @@ struct rockchip_pll_rate_table rk3288_pll_rates[] = {
 	{ /* sentinel */ },
 };
 
+#define RK3288_DIV_ACLK_CORE_M0_MASK	0xf
+#define RK3288_DIV_ACLK_CORE_M0_SHIFT	0
+#define RK3288_DIV_ACLK_CORE_MP_MASK	0xf
+#define RK3288_DIV_ACLK_CORE_MP_SHIFT	4
+#define RK3288_DIV_L2RAM_MASK		0x7
+#define RK3288_DIV_L2RAM_SHIFT		0
+#define RK3288_DIV_ATCLK_MASK		0x1f
+#define RK3288_DIV_ATCLK_SHIFT		4
+#define RK3288_DIV_PCLK_DBGPRE_MASK	0x1f
+#define RK3288_DIV_PCLK_DBGPRE_SHIFT	9
+
+#define RK3288_CLKSEL0(_core_m0, _core_mp)				\
+	{								\
+		.reg = RK3288_CLKSEL_CON(0),				\
+		.val = HIWORD_UPDATE(_core_m0, RK3288_DIV_ACLK_CORE_M0_MASK, \
+				RK3288_DIV_ACLK_CORE_M0_SHIFT) |	\
+		       HIWORD_UPDATE(_core_mp, RK3288_DIV_ACLK_CORE_MP_MASK, \
+				RK3288_DIV_ACLK_CORE_MP_SHIFT),		\
+	}
+#define RK3288_CLKSEL37(_l2ram, _atclk, _pclk_dbg_pre)			\
+	{								\
+		.reg = RK3288_CLKSEL_CON(37),				\
+		.val = HIWORD_UPDATE(_l2ram, RK3288_DIV_L2RAM_MASK,	\
+				RK3288_DIV_L2RAM_SHIFT) |		\
+		       HIWORD_UPDATE(_atclk, RK3288_DIV_ATCLK_MASK,	\
+				RK3288_DIV_ATCLK_SHIFT) |		\
+		       HIWORD_UPDATE(_pclk_dbg_pre,			\
+				RK3288_DIV_PCLK_DBGPRE_MASK,		\
+				RK3288_DIV_PCLK_DBGPRE_SHIFT),		\
+	}
+
+#define RK3288_CPUCLK_RATE(_prate, _core_m0, _core_mp, _l2ram, _atclk, _pdbg) \
+	{								\
+		.prate = _prate,					\
+		.divs = {						\
+			RK3288_CLKSEL0(_core_m0, _core_mp),		\
+			RK3288_CLKSEL37(_l2ram, _atclk, _pdbg),		\
+		},							\
+	}
+
+static struct rockchip_cpuclk_rate_table rk3288_cpuclk_rates[] = {
+	RK3288_CPUCLK_RATE(1800000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1704000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1608000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1512000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1416000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1200000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE(1008000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 816000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 696000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 600000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 408000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 312000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 216000000, 2, 4, 2, 4, 4),
+	RK3288_CPUCLK_RATE( 126000000, 2, 4, 2, 4, 4),
+	{ /* sentinel */ },
+};
+
+static const struct rockchip_cpuclk_reg_data rk3288_cpuclk_data = {
+	.core_reg = RK3288_CLKSEL_CON(0),
+	.div_core_shift = 8,
+	.div_core_mask = 0x1f,
+	.mux_core_shift = 15,
+};
+
 PNAME(mux_pll_p)		= { "xin24m", "xin32k" };
 PNAME(mux_armclk_p)		= { "apll_core", "gpll_core" };
 PNAME(mux_ddrphy_p)		= { "dpll_ddr", "gpll_ddr" };
@@ -166,8 +231,6 @@ static struct rockchip_clk_branch rk3288_clk_branches[] __initdata = {
 			RK3288_CLKGATE_CON(0), 1, GFLAGS),
 	GATE(0, "gpll_core", "gpll", 0,
 			RK3288_CLKGATE_CON(0), 2, GFLAGS),
-	COMPOSITE_NOGATE(0, "armclk", mux_armclk_p, 0,
-			RK3288_CLKSEL_CON(0), 15, 1, MFLAGS, 8, 5, DFLAGS),
 
 	COMPOSITE_NOMUX(0, "armcore0", "armclk", 0,
 			RK3288_CLKSEL_CON(36), 0, 3, DFLAGS | CLK_DIVIDER_READ_ONLY,
@@ -719,6 +782,10 @@ static void __init rk3288_clk_init(struct device_node *np)
 	rockchip_clk_protect_critical(rk3288_critical_clocks,
 				      ARRAY_SIZE(rk3288_critical_clocks));
 
+	rockchip_clk_register_armclk(ARMCLK, "armclk",
+			mux_armclk_p, ARRAY_SIZE(mux_armclk_p),
+			&rk3288_cpuclk_data, rk3288_cpuclk_rates);
+
 	rockchip_register_softrst(np, 9, reg_base + RK3288_SOFTRST_CON(0),
 				  ROCKCHIP_SOFTRST_HIWORD_MASK);
 }
-- 
2.0.1

[PATCH v2 2/7] clk: rockchip: fix rk3288 pll status register location

[Doug Anderson]

Heiko,

On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
> From: Jianqun <jay.xu@rock-chips.com>
>
> In RK3288, APLL lock status bit is in GRF_SOC_STATUS1,
> but in RK3188, is GRFSOC_STATUS0.
>
> Signed-off-by: Jianqun <jay.xu@rock-chips.com>
>
> Also name the constant accordingly as GRF_SOC_STATUS1
> to prevent confusion.
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  drivers/clk/rockchip/clk-rk3288.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>

[PATCH v2 4/7] clk: rockchip: make tightly bound armclk child-clocks read-only

[Doug Anderson]

Heiko,

On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
> Rockchip SoCs contain clocks tightly bound to the armclk, where the best
> rate / divider is supplied by the vendor after careful measuring.
> Often this ideal rate may be greater than the current rate.
>
> Therefore prevent the ccf from trying to set these dividers itself by
> setting them to read-only.
>
> In the case of the rk3066, this also includes the aclk_cpu, which makes it
> necessary to also split its direct child-clocks (pclk_cpu, hclk_cpu, ...)
> into individual definitions for rk3066 and rk3188.
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  drivers/clk/rockchip/clk-rk3188.c | 26 ++++++++++++++++++--------
>  drivers/clk/rockchip/clk-rk3288.c | 18 +++++++++---------
>  2 files changed, 27 insertions(+), 17 deletions(-)

This seems pretty reasonable to me.  I only glanced at rk3188 / rk3066
code quickly, but for rk3288 I can say:

Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>

[PATCH v2 6/7] clk: rockchip: add binding id for ARMCLK

[Doug Anderson]

Heiko,

On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  include/dt-bindings/clock/rk3188-cru-common.h | 1 +
>  include/dt-bindings/clock/rk3288-cru.h        | 1 +
>  2 files changed, 2 insertions(+)

A little silly to say that I tested adding #defines, but it does
compile and later patches work...

Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Doug Anderson]

Heiko,

On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
> When changing the armclk on Rockchip SoCs it is supposed to be reparented
> to an alternate parent before changing the underlying pll and back after
> the change. Additionally there exist clocks that are very tightly bound to
> the armclk whose divider values are set according to the armclk rate.
>
> Add a special clock-type to handle all that. The rate table and divider
> values will be supplied from the soc-specific clock controllers.
>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  drivers/clk/rockchip/Makefile  |   1 +
>  drivers/clk/rockchip/clk-cpu.c | 316 +++++++++++++++++++++++++++++++++++++++++
>  drivers/clk/rockchip/clk.c     |  20 +++
>  drivers/clk/rockchip/clk.h     |  36 +++++
>  4 files changed, 373 insertions(+)
>  create mode 100644 drivers/clk/rockchip/clk-cpu.c
>
> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
> index ee6b077..bd8514d 100644
> --- a/drivers/clk/rockchip/Makefile
> +++ b/drivers/clk/rockchip/Makefile
> @@ -5,6 +5,7 @@
>  obj-y  += clk-rockchip.o
>  obj-y  += clk.o
>  obj-y  += clk-pll.o
> +obj-y  += clk-cpu.o
>  obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
>
>  obj-y  += clk-rk3188.o
> diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
> new file mode 100644
> index 0000000..b8382b1
> --- /dev/null
> +++ b/drivers/clk/rockchip/clk-cpu.c
> @@ -0,0 +1,316 @@
> +/*
> + * Copyright (c) 2014 MundoReader S.L.
> + * Author: Heiko Stuebner <heiko@sntech.de>
> + *
> + * based on clk/samsung/clk-cpu.c
> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> + * Author: Thomas Abraham <thomas.ab@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This file contains the utility function to register CPU clock for Samsung
> + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a
> + * group of CPUs. The CPU clock is typically derived from a hierarchy of clock
> + * blocks which includes mux and divider blocks. There are a number of other
> + * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI
> + * clock for CPU domain. The rates of these auxiliary clocks are related to the
> + * CPU clock rate and this relation is usually specified in the hardware manual
> + * of the SoC or supplied after the SoC characterization.
> + *
> + * The below implementation of the CPU clock allows the rate changes of the CPU
> + * clock and the corresponding rate changes of the auxillary clocks of the CPU
> + * domain. The platform clock driver provides a clock register configuration
> + * for each configurable rate which is then used to program the clock hardware
> + * registers to acheive a fast co-oridinated rate change for all the CPU domain
> + * clocks.
> + *
> + * On a rate change request for the CPU clock, the rate change is propagated
> + * upto the PLL supplying the clock to the CPU domain clock blocks. While the
> + * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an
> + * alternate clock source. If required, the alternate clock source is divided
> + * down in order to keep the output clock rate within the previous OPP limits.
> + */
> +
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/clk-provider.h>
> +#include "clk.h"
> +
> +/**
> + * struct rockchip_cpuclk: information about clock supplied to a CPU core.
> + * @hw:                handle between ccf and cpu clock.
> + * @alt_parent:        alternate parent clock to use when switching the speed
> + *             of the primary parent clock.
> + * @reg_base:  base register for cpu-clock values.
> + * @clk_nb:    clock notifier registered for changes in clock speed of the
> + *             primary parent clock.
> + * @rate_count:        number of rates in the rate_table
> + * @rate_table:        pll-rates and their associated dividers
> + * @reg_data:  cpu-specific register settings
> + * @lock:      clock lock
> + */
> +struct rockchip_cpuclk {
> +       struct clk_hw                           hw;
> +
> +       struct clk_mux                          cpu_mux;
> +       const struct clk_ops                    *cpu_mux_ops;
> +
> +       struct clk                              *alt_parent;
> +       void __iomem                            *reg_base;
> +       struct notifier_block                   clk_nb;
> +       unsigned int                            rate_count;
> +       struct rockchip_cpuclk_rate_table       *rate_table;
> +       const struct rockchip_cpuclk_reg_data   *reg_data;
> +       spinlock_t                              *lock;
> +};
> +
> +#define to_rockchip_cpuclk_hw(hw) container_of(hw, struct rockchip_cpuclk, hw)
> +#define to_rockchip_cpuclk_nb(nb) \
> +                       container_of(nb, struct rockchip_cpuclk, clk_nb)
> +
> +static const struct rockchip_cpuclk_rate_table *rockchip_get_cpuclk_settings(
> +                           struct rockchip_cpuclk *cpuclk, unsigned long rate)
> +{
> +       const struct rockchip_cpuclk_rate_table *rate_table =
> +                                                       cpuclk->rate_table;
> +       int i;
> +
> +       for (i = 0; i < cpuclk->rate_count; i++) {
> +               if (rate == rate_table[i].prate)
> +                       return &rate_table[i];
> +       }
> +
> +       return NULL;
> +}
> +
> +static unsigned long rockchip_cpuclk_recalc_rate(struct clk_hw *hw,
> +                                       unsigned long parent_rate)
> +{
> +       struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_hw(hw);
> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
> +       u32 clksel0 = readl_relaxed(cpuclk->reg_base + reg_data->core_reg);
> +
> +       clksel0 >>= reg_data->div_core_shift;
> +       clksel0 &= reg_data->div_core_mask;
> +       return parent_rate / (clksel0 + 1);
> +}
> +
> +static const struct clk_ops rockchip_cpuclk_ops = {
> +       .recalc_rate = rockchip_cpuclk_recalc_rate,
> +};
> +
> +static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
> +                                          struct clk_notifier_data *ndata)
> +{
> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
> +       const struct rockchip_cpuclk_rate_table *rate;
> +       unsigned long alt_prate, alt_div;
> +       int i;
> +
> +       rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
> +       if (!rate) {
> +               pr_err("%s: Invalid rate : %lu for cpuclk\n",
> +                      __func__, ndata->new_rate);
> +               return -EINVAL;
> +       }
> +
> +       alt_prate = clk_get_rate(cpuclk->alt_parent);
> +
> +       spin_lock(cpuclk->lock);
> +
> +       /*
> +        * If the old parent clock speed is less than the clock speed
> +        * of the alternate parent, then it should be ensured that at no point
> +        * the armclk speed is more than the old_rate until the dividers are
> +        * set.
> +        */
> +       if (alt_prate > ndata->old_rate) {
> +               alt_div =  DIV_ROUND_UP(alt_prate, ndata->old_rate) - 1;
> +               if (alt_div > reg_data->div_core_mask) {
> +                       pr_warn("%s: limiting alt-divider %lu to %d\n",
> +                               __func__, alt_div, reg_data->div_core_mask);
> +                       alt_div = reg_data->div_core_mask;
> +               }
> +
> +               pr_debug("%s: setting div %lu as alt-rate %lu > old-rate %lu\n",
> +                        __func__, alt_div, alt_prate, ndata->old_rate);
> +               writel_relaxed(HIWORD_UPDATE(alt_div,
> +                                            reg_data->div_core_mask,
> +                                            reg_data->div_core_shift),
> +                             cpuclk->reg_base + reg_data->core_reg);
> +       }
> +
> +       /* select alternate parent */
> +       writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
> +              cpuclk->reg_base + reg_data->core_reg);

In the "alt_prate > ndata->old_rate" case there's a period of time
where you can be running super slow.

If we start as 126000 and we're going to switch to 594000, we decide
we need a divide by 5.  We apply the divide by 5 in one statement and
switch to 594MHz in a second statement.  That means there's a very
short period of time where we're at 126000 / 5 = 25200.  That's 25MHz.

I've found that when I stress out CPUfreq and have a lot of interrupts
coming in (like from USB) the my system hangs here.

Since the "alt div" and reparenting touch the same register, I think
we can do them in a single operation.  That works for me.

...but something isn't adding up for me, so I'm hesitant to suggest
this.  Somehow I only end up with the hang here and not down in the
post_rate_change().  I'll keep debugging...  It strangely enough seems
related to the rockchip_pll_notifier_cb()???


> +
> +       /* alternate parent is active now. set the dividers */
> +       for (i = 0; i < ARRAY_SIZE(rate->divs); i++) {
> +               const struct rockchip_cpuclk_clksel *clksel = &rate->divs[i];
> +
> +               if (!clksel->reg)
> +                       continue;
> +
> +               pr_debug("%s: setting reg 0x%x to 0x%x\n",
> +                        __func__, clksel->reg, clksel->val);
> +               writel(clksel->val , cpuclk->reg_base + clksel->reg);
> +       }
> +
> +       spin_unlock(cpuclk->lock);
> +       return 0;
> +}
> +
> +static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
> +                                           struct clk_notifier_data *ndata)
> +{
> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
> +
> +       spin_lock(cpuclk->lock);
> +
> +       /* post-rate change event, re-mux back to primary parent */
> +       writel(HIWORD_UPDATE(0, 1, reg_data->mux_core_shift),
> +              cpuclk->reg_base + reg_data->core_reg);
> +
> +       /* remove any core dividers */
> +       writel(HIWORD_UPDATE(0, reg_data->div_core_mask,
> +                            reg_data->div_core_shift),
> +              cpuclk->reg_base + reg_data->core_reg);

I think we can combine the two writes above too.  If we combine the
pre, we should also combine here...


> +
> +       spin_unlock(cpuclk->lock);
> +       return 0;
> +}
> +
> +/*
> + * This clock notifier is called when the frequency of the parent clock
> + * of cpuclk is to be changed. This notifier handles the setting up all
> + * the divider clocks, remux to temporary parent and handling the safe
> + * frequency levels when using temporary parent.
> + */
> +static int rockchip_cpuclk_notifier_cb(struct notifier_block *nb,
> +                                       unsigned long event, void *data)
> +{
> +       struct clk_notifier_data *ndata = data;
> +       struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_nb(nb);
> +       int ret = 0;
> +
> +       pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
> +                __func__, event, ndata->old_rate, ndata->new_rate);
> +       if (event == PRE_RATE_CHANGE)
> +               ret = rockchip_cpuclk_pre_rate_change(cpuclk, ndata);
> +       else if (event == POST_RATE_CHANGE)
> +               ret = rockchip_cpuclk_post_rate_change(cpuclk, ndata);
> +
> +       return notifier_from_errno(ret);
> +}
> +
> +struct clk *rockchip_clk_register_cpuclk(const char *name,
> +                       const char **parent_names, u8 num_parents,
> +                       const struct rockchip_cpuclk_reg_data *reg_data,
> +                       struct rockchip_cpuclk_rate_table *rate_table,
> +                       void __iomem *reg_base, spinlock_t *lock)
> +{
> +       struct rockchip_cpuclk *cpuclk;
> +       struct clk_init_data init;
> +       struct clk *clk, *cclk;
> +       int ret;
> +
> +       if (!reg_data) {
> +               pr_err("%s: no soc register information\n", __func__);
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       if (num_parents != 2) {
> +               pr_err("%s: needs two parent clocks\n", __func__);
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
> +       if (!cpuclk)
> +               return ERR_PTR(-ENOMEM);
> +
> +       init.name = name;
> +       init.parent_names = &parent_names[0];
> +       init.num_parents = 1;
> +       init.ops = &rockchip_cpuclk_ops;
> +
> +       /* only allow rate changes when we have a rate table */
> +       init.flags = rate_table ? CLK_SET_RATE_PARENT : 0;
> +
> +       /* disallow automatic parent changes by ccf */
> +       init.flags |= CLK_SET_RATE_NO_REPARENT;

For me it was important to add "CLK_GET_RATE_NOCACHE" here.  We're
mucking with this divider ourselves (above) so we need to make sure
that the clock framework isn't doing something wonky.

If I don't do that and I run this:

cd /sys/devices/system/cpu/cpu0/cpufreq
echo userspace > scaling_governor
while true; do
  echo 126000 > scaling_setspeed
  sleep .1
  echo 216000 > scaling_setspeed
  sleep .1
done

...and then in another session I run:

cd /sys/devices/system/cpu/cpu0/cpufreq
while true; do cat cpuinfo_cur_freq; sleep .2; done

...I see all sorts of wonky results.

> +
> +       cpuclk->reg_base = reg_base;
> +       cpuclk->lock = lock;
> +       cpuclk->reg_data = reg_data;
> +       cpuclk->clk_nb.notifier_call = rockchip_cpuclk_notifier_cb;
> +       cpuclk->hw.init = &init;
> +
> +       cpuclk->alt_parent = __clk_lookup(parent_names[1]);
> +       if (!cpuclk->alt_parent) {
> +               pr_err("%s: could not lookup alternate parent\n",
> +                      __func__);
> +               ret = -EINVAL;
> +               goto free_cpuclk;
> +       }
> +
> +       ret = clk_prepare_enable(cpuclk->alt_parent);
> +       if (ret) {
> +               pr_err("%s: could not enable alternate parent\n",
> +                      __func__);
> +               goto free_cpuclk;
> +       }
> +
> +       clk = __clk_lookup(parent_names[0]);
> +       if (!clk) {
> +               pr_err("%s: could not lookup parent clock %s\n",
> +                      __func__, parent_names[0]);
> +               ret = -EINVAL;
> +               goto free_cpuclk;
> +       }
> +
> +       ret = clk_notifier_register(clk, &cpuclk->clk_nb);
> +       if (ret) {
> +               pr_err("%s: failed to register clock notifier for %s\n",
> +                               __func__, name);
> +               goto free_cpuclk;
> +       }
> +
> +       if (rate_table) {
> +               int nrates;
> +
> +               /* find count of rates in rate_table */
> +               for (nrates = 0; rate_table[nrates].prate != 0; )
> +                       nrates++;
> +
> +               cpuclk->rate_count = nrates;
> +               cpuclk->rate_table = kmemdup(rate_table,
> +                                            sizeof(*rate_table) * nrates,
> +                                            GFP_KERNEL);
> +               if (!cpuclk->rate_table) {
> +                       pr_err("%s: could not allocate memory for cpuclk rates\n",
> +                              __func__);
> +                       ret = -ENOMEM;
> +                       goto unregister_notifier;
> +               }
> +       }
> +
> +       cclk = clk_register(NULL, &cpuclk->hw);
> +       if (IS_ERR(clk)) {
> +               pr_err("%s: could not register cpuclk %s\n", __func__,  name);
> +               ret = PTR_ERR(clk);
> +               goto free_rate_table;
> +       }
> +
> +       return cclk;
> +
> +free_rate_table:
> +       kfree(cpuclk->rate_table);
> +unregister_notifier:
> +       clk_notifier_unregister(clk, &cpuclk->clk_nb);
> +free_cpuclk:
> +       kfree(cpuclk);
> +       return ERR_PTR(ret);
> +}
> diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
> index d9c6db2..f87ac4a 100644
> --- a/drivers/clk/rockchip/clk.c
> +++ b/drivers/clk/rockchip/clk.c
> @@ -297,6 +297,26 @@ void __init rockchip_clk_register_branches(
>         }
>  }
>
> +void __init rockchip_clk_register_armclk(unsigned int lookup_id,
> +                       const char *name, const char **parent_names,
> +                       u8 num_parents,
> +                       const struct rockchip_cpuclk_reg_data *reg_data,
> +                       struct rockchip_cpuclk_rate_table *rate_table)
> +{
> +       struct clk *clk;
> +
> +       clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
> +                                          reg_data, rate_table, reg_base,
> +                                          &clk_lock);
> +       if (IS_ERR(clk)) {
> +               pr_err("%s: failed to register clock %s: %ld\n",
> +                      __func__, name, PTR_ERR(clk));
> +               return;
> +       }
> +
> +       rockchip_clk_add_lookup(clk, lookup_id);
> +}
> +
>  void __init rockchip_clk_protect_critical(const char *clocks[], int nclocks)
>  {
>         int i;
> diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
> index 2b0bca1..e0ea61e 100644
> --- a/drivers/clk/rockchip/clk.h
> +++ b/drivers/clk/rockchip/clk.h
> @@ -120,6 +120,38 @@ struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
>                 struct rockchip_pll_rate_table *rate_table,
>                 spinlock_t *lock);
>
> +struct rockchip_cpuclk_clksel {
> +       int reg;
> +       u32 val;
> +};
> +
> +#define ROCKCHIP_CPUCLK_NUM_DIVIDERS   2
> +struct rockchip_cpuclk_rate_table {
> +       unsigned long prate;
> +       struct rockchip_cpuclk_clksel divs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
> +};
> +
> +/**
> + * struct rockchip_cpuclk_reg_data: describes register offsets and masks of the cpuclock
> + * @core_reg:          register offset of the core settings register
> + * @div_core_shift:    core divider offset used to divide the pll value
> + * @div_core_mask:     core divider mask
> + * @mux_core_shift:    offset of the core multiplexer
> + */
> +struct rockchip_cpuclk_reg_data {
> +       int             core_reg;
> +       u8              div_core_shift;
> +       u32             div_core_mask;
> +       int             mux_core_reg;
> +       u8              mux_core_shift;
> +};
> +
> +struct clk *rockchip_clk_register_cpuclk(const char *name,
> +                       const char **parent_names, u8 num_parents,
> +                       const struct rockchip_cpuclk_reg_data *reg_data,
> +                       struct rockchip_cpuclk_rate_table *rate_table,
> +                       void __iomem *reg_base, spinlock_t *lock);
> +
>  #define PNAME(x) static const char *x[] __initconst
>
>  enum rockchip_clk_branch_type {
> @@ -329,6 +361,10 @@ void rockchip_clk_register_branches(struct rockchip_clk_branch *clk_list,
>                                     unsigned int nr_clk);
>  void rockchip_clk_register_plls(struct rockchip_pll_clock *pll_list,
>                                 unsigned int nr_pll, int grf_lock_offset);
> +void rockchip_clk_register_armclk(unsigned int lookup_id, const char *name,
> +                       const char **parent_names, u8 num_parents,
> +                       const struct rockchip_cpuclk_reg_data *reg_data,
> +                       struct rockchip_cpuclk_rate_table *rate_table);
>  void rockchip_clk_protect_critical(const char *clocks[], int nclocks);
>
>  #define ROCKCHIP_SOFTRST_HIWORD_MASK   BIT(0)
> --
> 2.0.1
>

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Doug Anderson]

Hi,

On Mon, Sep 15, 2014 at 4:58 PM, Doug Anderson <dianders@chromium.org> wrote:
> Heiko,
>
> On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
>> When changing the armclk on Rockchip SoCs it is supposed to be reparented
>> to an alternate parent before changing the underlying pll and back after
>> the change. Additionally there exist clocks that are very tightly bound to
>> the armclk whose divider values are set according to the armclk rate.
>>
>> Add a special clock-type to handle all that. The rate table and divider
>> values will be supplied from the soc-specific clock controllers.
>>
>> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
>> ---
>>  drivers/clk/rockchip/Makefile  |   1 +
>>  drivers/clk/rockchip/clk-cpu.c | 316 +++++++++++++++++++++++++++++++++++++++++
>>  drivers/clk/rockchip/clk.c     |  20 +++
>>  drivers/clk/rockchip/clk.h     |  36 +++++
>>  4 files changed, 373 insertions(+)
>>  create mode 100644 drivers/clk/rockchip/clk-cpu.c
>>
>> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
>> index ee6b077..bd8514d 100644
>> --- a/drivers/clk/rockchip/Makefile
>> +++ b/drivers/clk/rockchip/Makefile
>> @@ -5,6 +5,7 @@
>>  obj-y  += clk-rockchip.o
>>  obj-y  += clk.o
>>  obj-y  += clk-pll.o
>> +obj-y  += clk-cpu.o
>>  obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
>>
>>  obj-y  += clk-rk3188.o
>> diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
>> new file mode 100644
>> index 0000000..b8382b1
>> --- /dev/null
>> +++ b/drivers/clk/rockchip/clk-cpu.c
>> @@ -0,0 +1,316 @@
>> +/*
>> + * Copyright (c) 2014 MundoReader S.L.
>> + * Author: Heiko Stuebner <heiko@sntech.de>
>> + *
>> + * based on clk/samsung/clk-cpu.c
>> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
>> + * Author: Thomas Abraham <thomas.ab@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This file contains the utility function to register CPU clock for Samsung
>> + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a
>> + * group of CPUs. The CPU clock is typically derived from a hierarchy of clock
>> + * blocks which includes mux and divider blocks. There are a number of other
>> + * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI
>> + * clock for CPU domain. The rates of these auxiliary clocks are related to the
>> + * CPU clock rate and this relation is usually specified in the hardware manual
>> + * of the SoC or supplied after the SoC characterization.
>> + *
>> + * The below implementation of the CPU clock allows the rate changes of the CPU
>> + * clock and the corresponding rate changes of the auxillary clocks of the CPU
>> + * domain. The platform clock driver provides a clock register configuration
>> + * for each configurable rate which is then used to program the clock hardware
>> + * registers to acheive a fast co-oridinated rate change for all the CPU domain
>> + * clocks.
>> + *
>> + * On a rate change request for the CPU clock, the rate change is propagated
>> + * upto the PLL supplying the clock to the CPU domain clock blocks. While the
>> + * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an
>> + * alternate clock source. If required, the alternate clock source is divided
>> + * down in order to keep the output clock rate within the previous OPP limits.
>> + */
>> +
>> +#include <linux/of.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/clk-provider.h>
>> +#include "clk.h"
>> +
>> +/**
>> + * struct rockchip_cpuclk: information about clock supplied to a CPU core.
>> + * @hw:                handle between ccf and cpu clock.
>> + * @alt_parent:        alternate parent clock to use when switching the speed
>> + *             of the primary parent clock.
>> + * @reg_base:  base register for cpu-clock values.
>> + * @clk_nb:    clock notifier registered for changes in clock speed of the
>> + *             primary parent clock.
>> + * @rate_count:        number of rates in the rate_table
>> + * @rate_table:        pll-rates and their associated dividers
>> + * @reg_data:  cpu-specific register settings
>> + * @lock:      clock lock
>> + */
>> +struct rockchip_cpuclk {
>> +       struct clk_hw                           hw;
>> +
>> +       struct clk_mux                          cpu_mux;
>> +       const struct clk_ops                    *cpu_mux_ops;
>> +
>> +       struct clk                              *alt_parent;
>> +       void __iomem                            *reg_base;
>> +       struct notifier_block                   clk_nb;
>> +       unsigned int                            rate_count;
>> +       struct rockchip_cpuclk_rate_table       *rate_table;
>> +       const struct rockchip_cpuclk_reg_data   *reg_data;
>> +       spinlock_t                              *lock;
>> +};
>> +
>> +#define to_rockchip_cpuclk_hw(hw) container_of(hw, struct rockchip_cpuclk, hw)
>> +#define to_rockchip_cpuclk_nb(nb) \
>> +                       container_of(nb, struct rockchip_cpuclk, clk_nb)
>> +
>> +static const struct rockchip_cpuclk_rate_table *rockchip_get_cpuclk_settings(
>> +                           struct rockchip_cpuclk *cpuclk, unsigned long rate)
>> +{
>> +       const struct rockchip_cpuclk_rate_table *rate_table =
>> +                                                       cpuclk->rate_table;
>> +       int i;
>> +
>> +       for (i = 0; i < cpuclk->rate_count; i++) {
>> +               if (rate == rate_table[i].prate)
>> +                       return &rate_table[i];
>> +       }
>> +
>> +       return NULL;
>> +}
>> +
>> +static unsigned long rockchip_cpuclk_recalc_rate(struct clk_hw *hw,
>> +                                       unsigned long parent_rate)
>> +{
>> +       struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_hw(hw);
>> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
>> +       u32 clksel0 = readl_relaxed(cpuclk->reg_base + reg_data->core_reg);
>> +
>> +       clksel0 >>= reg_data->div_core_shift;
>> +       clksel0 &= reg_data->div_core_mask;
>> +       return parent_rate / (clksel0 + 1);
>> +}
>> +
>> +static const struct clk_ops rockchip_cpuclk_ops = {
>> +       .recalc_rate = rockchip_cpuclk_recalc_rate,
>> +};
>> +
>> +static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
>> +                                          struct clk_notifier_data *ndata)
>> +{
>> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
>> +       const struct rockchip_cpuclk_rate_table *rate;
>> +       unsigned long alt_prate, alt_div;
>> +       int i;
>> +
>> +       rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
>> +       if (!rate) {
>> +               pr_err("%s: Invalid rate : %lu for cpuclk\n",
>> +                      __func__, ndata->new_rate);
>> +               return -EINVAL;
>> +       }
>> +
>> +       alt_prate = clk_get_rate(cpuclk->alt_parent);
>> +
>> +       spin_lock(cpuclk->lock);
>> +
>> +       /*
>> +        * If the old parent clock speed is less than the clock speed
>> +        * of the alternate parent, then it should be ensured that at no point
>> +        * the armclk speed is more than the old_rate until the dividers are
>> +        * set.
>> +        */
>> +       if (alt_prate > ndata->old_rate) {
>> +               alt_div =  DIV_ROUND_UP(alt_prate, ndata->old_rate) - 1;
>> +               if (alt_div > reg_data->div_core_mask) {
>> +                       pr_warn("%s: limiting alt-divider %lu to %d\n",
>> +                               __func__, alt_div, reg_data->div_core_mask);
>> +                       alt_div = reg_data->div_core_mask;
>> +               }
>> +
>> +               pr_debug("%s: setting div %lu as alt-rate %lu > old-rate %lu\n",
>> +                        __func__, alt_div, alt_prate, ndata->old_rate);
>> +               writel_relaxed(HIWORD_UPDATE(alt_div,
>> +                                            reg_data->div_core_mask,
>> +                                            reg_data->div_core_shift),
>> +                             cpuclk->reg_base + reg_data->core_reg);
>> +       }
>> +
>> +       /* select alternate parent */
>> +       writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
>> +              cpuclk->reg_base + reg_data->core_reg);
>
> In the "alt_prate > ndata->old_rate" case there's a period of time
> where you can be running super slow.
>
> If we start as 126000 and we're going to switch to 594000, we decide
> we need a divide by 5.  We apply the divide by 5 in one statement and
> switch to 594MHz in a second statement.  That means there's a very
> short period of time where we're at 126000 / 5 = 25200.  That's 25MHz.
>
> I've found that when I stress out CPUfreq and have a lot of interrupts
> coming in (like from USB) the my system hangs here.
>
> Since the "alt div" and reparenting touch the same register, I think
> we can do them in a single operation.  That works for me.
>
> ...but something isn't adding up for me, so I'm hesitant to suggest
> this.  Somehow I only end up with the hang here and not down in the
> post_rate_change().  I'll keep debugging...  It strangely enough seems
> related to the rockchip_pll_notifier_cb()???

Oh.  Out of time to debug again, but it almost looks like we go down
to the 24MHz clock in rockchip_pll_notifier_cb().  Then we do a / 5 on
that.  ...so it's not 25MHz that we're running at.  It's 5.

I'll do more to confirm / debug tomorrow.

-Doug

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Kever Yang]

Hi Doug,

On 09/16/2014 07:58 AM, Doug Anderson wrote:
> Heiko,
>
> On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
>> When changing the armclk on Rockchip SoCs it is supposed to be reparented
>> to an alternate parent before changing the underlying pll and back after
>> the change. Additionally there exist clocks that are very tightly bound to
>> the armclk whose divider values are set according to the armclk rate.
>>
>> Add a special clock-type to handle all that. The rate table and divider
>> values will be supplied from the soc-specific clock controllers.
>>
>> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
>> ---
>>   drivers/clk/rockchip/Makefile  |   1 +
>>   drivers/clk/rockchip/clk-cpu.c | 316 +++++++++++++++++++++++++++++++++++++++++
>>   drivers/clk/rockchip/clk.c     |  20 +++
>>   drivers/clk/rockchip/clk.h     |  36 +++++
>>   4 files changed, 373 insertions(+)
>>   create mode 100644 drivers/clk/rockchip/clk-cpu.c
>>
>> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
>> index ee6b077..bd8514d 100644
>> --- a/drivers/clk/rockchip/Makefile
>> +++ b/drivers/clk/rockchip/Makefile
>> @@ -5,6 +5,7 @@
>>   obj-y  += clk-rockchip.o
>>   obj-y  += clk.o
>>   obj-y  += clk-pll.o
>> +obj-y  += clk-cpu.o
>>   obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
>>
>>   obj-y  += clk-rk3188.o
>> diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
>> new file mode 100644
>> index 0000000..b8382b1
>> --- /dev/null
>> +++ b/drivers/clk/rockchip/clk-cpu.c
>> @@ -0,0 +1,316 @@
>> +/*
>> + * Copyright (c) 2014 MundoReader S.L.
>> + * Author: Heiko Stuebner <heiko@sntech.de>
>> + *
>> + * based on clk/samsung/clk-cpu.c
>> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
>> + * Author: Thomas Abraham <thomas.ab@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This file contains the utility function to register CPU clock for Samsung
>> + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a
>> + * group of CPUs. The CPU clock is typically derived from a hierarchy of clock
>> + * blocks which includes mux and divider blocks. There are a number of other
>> + * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI
>> + * clock for CPU domain. The rates of these auxiliary clocks are related to the
>> + * CPU clock rate and this relation is usually specified in the hardware manual
>> + * of the SoC or supplied after the SoC characterization.
>> + *
>> + * The below implementation of the CPU clock allows the rate changes of the CPU
>> + * clock and the corresponding rate changes of the auxillary clocks of the CPU
>> + * domain. The platform clock driver provides a clock register configuration
>> + * for each configurable rate which is then used to program the clock hardware
>> + * registers to acheive a fast co-oridinated rate change for all the CPU domain
>> + * clocks.
>> + *
>> + * On a rate change request for the CPU clock, the rate change is propagated
>> + * upto the PLL supplying the clock to the CPU domain clock blocks. While the
>> + * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an
>> + * alternate clock source. If required, the alternate clock source is divided
>> + * down in order to keep the output clock rate within the previous OPP limits.
>> + */
>> +
>> +#include <linux/of.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/clk-provider.h>
>> +#include "clk.h"
>> +
>> +/**
>> + * struct rockchip_cpuclk: information about clock supplied to a CPU core.
>> + * @hw:                handle between ccf and cpu clock.
>> + * @alt_parent:        alternate parent clock to use when switching the speed
>> + *             of the primary parent clock.
>> + * @reg_base:  base register for cpu-clock values.
>> + * @clk_nb:    clock notifier registered for changes in clock speed of the
>> + *             primary parent clock.
>> + * @rate_count:        number of rates in the rate_table
>> + * @rate_table:        pll-rates and their associated dividers
>> + * @reg_data:  cpu-specific register settings
>> + * @lock:      clock lock
>> + */
>> +struct rockchip_cpuclk {
>> +       struct clk_hw                           hw;
>> +
>> +       struct clk_mux                          cpu_mux;
>> +       const struct clk_ops                    *cpu_mux_ops;
>> +
>> +       struct clk                              *alt_parent;
>> +       void __iomem                            *reg_base;
>> +       struct notifier_block                   clk_nb;
>> +       unsigned int                            rate_count;
>> +       struct rockchip_cpuclk_rate_table       *rate_table;
>> +       const struct rockchip_cpuclk_reg_data   *reg_data;
>> +       spinlock_t                              *lock;
>> +};
>> +
>> +#define to_rockchip_cpuclk_hw(hw) container_of(hw, struct rockchip_cpuclk, hw)
>> +#define to_rockchip_cpuclk_nb(nb) \
>> +                       container_of(nb, struct rockchip_cpuclk, clk_nb)
>> +
>> +static const struct rockchip_cpuclk_rate_table *rockchip_get_cpuclk_settings(
>> +                           struct rockchip_cpuclk *cpuclk, unsigned long rate)
>> +{
>> +       const struct rockchip_cpuclk_rate_table *rate_table =
>> +                                                       cpuclk->rate_table;
>> +       int i;
>> +
>> +       for (i = 0; i < cpuclk->rate_count; i++) {
>> +               if (rate == rate_table[i].prate)
>> +                       return &rate_table[i];
>> +       }
>> +
>> +       return NULL;
>> +}
>> +
>> +static unsigned long rockchip_cpuclk_recalc_rate(struct clk_hw *hw,
>> +                                       unsigned long parent_rate)
>> +{
>> +       struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_hw(hw);
>> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
>> +       u32 clksel0 = readl_relaxed(cpuclk->reg_base + reg_data->core_reg);
>> +
>> +       clksel0 >>= reg_data->div_core_shift;
>> +       clksel0 &= reg_data->div_core_mask;
>> +       return parent_rate / (clksel0 + 1);
>> +}
>> +
>> +static const struct clk_ops rockchip_cpuclk_ops = {
>> +       .recalc_rate = rockchip_cpuclk_recalc_rate,
>> +};
>> +
>> +static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
>> +                                          struct clk_notifier_data *ndata)
>> +{
>> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
>> +       const struct rockchip_cpuclk_rate_table *rate;
>> +       unsigned long alt_prate, alt_div;
>> +       int i;
>> +
>> +       rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
>> +       if (!rate) {
>> +               pr_err("%s: Invalid rate : %lu for cpuclk\n",
>> +                      __func__, ndata->new_rate);
>> +               return -EINVAL;
>> +       }
>> +
>> +       alt_prate = clk_get_rate(cpuclk->alt_parent);
>> +
>> +       spin_lock(cpuclk->lock);
>> +
>> +       /*
>> +        * If the old parent clock speed is less than the clock speed
>> +        * of the alternate parent, then it should be ensured that at no point
>> +        * the armclk speed is more than the old_rate until the dividers are
>> +        * set.
>> +        */
>> +       if (alt_prate > ndata->old_rate) {
>> +               alt_div =  DIV_ROUND_UP(alt_prate, ndata->old_rate) - 1;
>> +               if (alt_div > reg_data->div_core_mask) {
>> +                       pr_warn("%s: limiting alt-divider %lu to %d\n",
>> +                               __func__, alt_div, reg_data->div_core_mask);
>> +                       alt_div = reg_data->div_core_mask;
>> +               }
>> +
>> +               pr_debug("%s: setting div %lu as alt-rate %lu > old-rate %lu\n",
>> +                        __func__, alt_div, alt_prate, ndata->old_rate);
>> +               writel_relaxed(HIWORD_UPDATE(alt_div,
>> +                                            reg_data->div_core_mask,
>> +                                            reg_data->div_core_shift),
>> +                             cpuclk->reg_base + reg_data->core_reg);
>> +       }
>> +
>> +       /* select alternate parent */
>> +       writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
>> +              cpuclk->reg_base + reg_data->core_reg);
> In the "alt_prate > ndata->old_rate" case there's a period of time
> where you can be running super slow.
>
> If we start as 126000 and we're going to switch to 594000, we decide
> we need a divide by 5.  We apply the divide by 5 in one statement and
> switch to 594MHz in a second statement.  That means there's a very
> short period of time where we're at 126000 / 5 = 25200.  That's 25MHz.
>
> I've found that when I stress out CPUfreq and have a lot of interrupts
> coming in (like from USB) the my system hangs here.
>
> Since the "alt div" and reparenting touch the same register, I think
> we can do them in a single operation.  That works for me.
Agree, this should be work, the operation for div and parent select for
arm clk is in the same register in rk3066, rk3188 and rk3288.
>
> ...but something isn't adding up for me, so I'm hesitant to suggest
> this.  Somehow I only end up with the hang here and not down in the
> post_rate_change().  I'll keep debugging...  It strangely enough seems
> related to the rockchip_pll_notifier_cb()???
Did you test this on Gerrit 3.14? I think we have a know problem that make
POST_RATE_CHANGE notifier is not send which has been fixed by Derek.
>
>
>> +
>> +       /* alternate parent is active now. set the dividers */
>> +       for (i = 0; i < ARRAY_SIZE(rate->divs); i++) {
>> +               const struct rockchip_cpuclk_clksel *clksel = &rate->divs[i];
>> +
>> +               if (!clksel->reg)
>> +                       continue;
>> +
>> +               pr_debug("%s: setting reg 0x%x to 0x%x\n",
>> +                        __func__, clksel->reg, clksel->val);
>> +               writel(clksel->val , cpuclk->reg_base + clksel->reg);
>> +       }
>> +
>> +       spin_unlock(cpuclk->lock);
>> +       return 0;
>> +}
>> +
>> +static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
>> +                                           struct clk_notifier_data *ndata)
>> +{
>> +       const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
>> +
>> +       spin_lock(cpuclk->lock);
>> +
>> +       /* post-rate change event, re-mux back to primary parent */
>> +       writel(HIWORD_UPDATE(0, 1, reg_data->mux_core_shift),
>> +              cpuclk->reg_base + reg_data->core_reg);
>> +
>> +       /* remove any core dividers */
>> +       writel(HIWORD_UPDATE(0, reg_data->div_core_mask,
>> +                            reg_data->div_core_shift),
>> +              cpuclk->reg_base + reg_data->core_reg);
> I think we can combine the two writes above too.  If we combine the
> pre, we should also combine here...
>
>
>> +
>> +       spin_unlock(cpuclk->lock);
>> +       return 0;
>> +}
>> +
>> +/*
>> + * This clock notifier is called when the frequency of the parent clock
>> + * of cpuclk is to be changed. This notifier handles the setting up all
>> + * the divider clocks, remux to temporary parent and handling the safe
>> + * frequency levels when using temporary parent.
>> + */
>> +static int rockchip_cpuclk_notifier_cb(struct notifier_block *nb,
>> +                                       unsigned long event, void *data)
>> +{
>> +       struct clk_notifier_data *ndata = data;
>> +       struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_nb(nb);
>> +       int ret = 0;
>> +
>> +       pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
>> +                __func__, event, ndata->old_rate, ndata->new_rate);
>> +       if (event == PRE_RATE_CHANGE)
>> +               ret = rockchip_cpuclk_pre_rate_change(cpuclk, ndata);
>> +       else if (event == POST_RATE_CHANGE)
>> +               ret = rockchip_cpuclk_post_rate_change(cpuclk, ndata);
>> +
>> +       return notifier_from_errno(ret);
>> +}
>> +
>> +struct clk *rockchip_clk_register_cpuclk(const char *name,
>> +                       const char **parent_names, u8 num_parents,
>> +                       const struct rockchip_cpuclk_reg_data *reg_data,
>> +                       struct rockchip_cpuclk_rate_table *rate_table,
>> +                       void __iomem *reg_base, spinlock_t *lock)
>> +{
>> +       struct rockchip_cpuclk *cpuclk;
>> +       struct clk_init_data init;
>> +       struct clk *clk, *cclk;
>> +       int ret;
>> +
>> +       if (!reg_data) {
>> +               pr_err("%s: no soc register information\n", __func__);
>> +               return ERR_PTR(-EINVAL);
>> +       }
>> +
>> +       if (num_parents != 2) {
>> +               pr_err("%s: needs two parent clocks\n", __func__);
>> +               return ERR_PTR(-EINVAL);
>> +       }
>> +
>> +       cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
>> +       if (!cpuclk)
>> +               return ERR_PTR(-ENOMEM);
>> +
>> +       init.name = name;
>> +       init.parent_names = &parent_names[0];
>> +       init.num_parents = 1;
>> +       init.ops = &rockchip_cpuclk_ops;
>> +
>> +       /* only allow rate changes when we have a rate table */
>> +       init.flags = rate_table ? CLK_SET_RATE_PARENT : 0;
>> +
>> +       /* disallow automatic parent changes by ccf */
>> +       init.flags |= CLK_SET_RATE_NO_REPARENT;
> For me it was important to add "CLK_GET_RATE_NOCACHE" here.  We're
> mucking with this divider ourselves (above) so we need to make sure
> that the clock framework isn't doing something wonky.
>
> If I don't do that and I run this:
>
> cd /sys/devices/system/cpu/cpu0/cpufreq
> echo userspace > scaling_governor
> while true; do
>    echo 126000 > scaling_setspeed
>    sleep .1
>    echo 216000 > scaling_setspeed
>    sleep .1
> done
>
> ...and then in another session I run:
>
> cd /sys/devices/system/cpu/cpu0/cpufreq
> while true; do cat cpuinfo_cur_freq; sleep .2; done
>
> ...I see all sorts of wonky results.
>
>> +
>> +       cpuclk->reg_base = reg_base;
>> +       cpuclk->lock = lock;
>> +       cpuclk->reg_data = reg_data;
>> +       cpuclk->clk_nb.notifier_call = rockchip_cpuclk_notifier_cb;
>> +       cpuclk->hw.init = &init;
>> +
>> +       cpuclk->alt_parent = __clk_lookup(parent_names[1]);
>> +       if (!cpuclk->alt_parent) {
>> +               pr_err("%s: could not lookup alternate parent\n",
>> +                      __func__);
>> +               ret = -EINVAL;
>> +               goto free_cpuclk;
>> +       }
>> +
>> +       ret = clk_prepare_enable(cpuclk->alt_parent);
>> +       if (ret) {
>> +               pr_err("%s: could not enable alternate parent\n",
>> +                      __func__);
>> +               goto free_cpuclk;
>> +       }
>> +
>> +       clk = __clk_lookup(parent_names[0]);
>> +       if (!clk) {
>> +               pr_err("%s: could not lookup parent clock %s\n",
>> +                      __func__, parent_names[0]);
>> +               ret = -EINVAL;
>> +               goto free_cpuclk;
>> +       }
>> +
>> +       ret = clk_notifier_register(clk, &cpuclk->clk_nb);
>> +       if (ret) {
>> +               pr_err("%s: failed to register clock notifier for %s\n",
>> +                               __func__, name);
>> +               goto free_cpuclk;
>> +       }
>> +
>> +       if (rate_table) {
>> +               int nrates;
>> +
>> +               /* find count of rates in rate_table */
>> +               for (nrates = 0; rate_table[nrates].prate != 0; )
>> +                       nrates++;
>> +
>> +               cpuclk->rate_count = nrates;
>> +               cpuclk->rate_table = kmemdup(rate_table,
>> +                                            sizeof(*rate_table) * nrates,
>> +                                            GFP_KERNEL);
>> +               if (!cpuclk->rate_table) {
>> +                       pr_err("%s: could not allocate memory for cpuclk rates\n",
>> +                              __func__);
>> +                       ret = -ENOMEM;
>> +                       goto unregister_notifier;
>> +               }
>> +       }
>> +
>> +       cclk = clk_register(NULL, &cpuclk->hw);
>> +       if (IS_ERR(clk)) {
>> +               pr_err("%s: could not register cpuclk %s\n", __func__,  name);
>> +               ret = PTR_ERR(clk);
>> +               goto free_rate_table;
>> +       }
>> +
>> +       return cclk;
>> +
>> +free_rate_table:
>> +       kfree(cpuclk->rate_table);
>> +unregister_notifier:
>> +       clk_notifier_unregister(clk, &cpuclk->clk_nb);
>> +free_cpuclk:
>> +       kfree(cpuclk);
>> +       return ERR_PTR(ret);
>> +}
>> diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
>> index d9c6db2..f87ac4a 100644
>> --- a/drivers/clk/rockchip/clk.c
>> +++ b/drivers/clk/rockchip/clk.c
>> @@ -297,6 +297,26 @@ void __init rockchip_clk_register_branches(
>>          }
>>   }
>>
>> +void __init rockchip_clk_register_armclk(unsigned int lookup_id,
>> +                       const char *name, const char **parent_names,
>> +                       u8 num_parents,
>> +                       const struct rockchip_cpuclk_reg_data *reg_data,
>> +                       struct rockchip_cpuclk_rate_table *rate_table)
>> +{
>> +       struct clk *clk;
>> +
>> +       clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
>> +                                          reg_data, rate_table, reg_base,
>> +                                          &clk_lock);
>> +       if (IS_ERR(clk)) {
>> +               pr_err("%s: failed to register clock %s: %ld\n",
>> +                      __func__, name, PTR_ERR(clk));
>> +               return;
>> +       }
>> +
>> +       rockchip_clk_add_lookup(clk, lookup_id);
>> +}
>> +
>>   void __init rockchip_clk_protect_critical(const char *clocks[], int nclocks)
>>   {
>>          int i;
>> diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
>> index 2b0bca1..e0ea61e 100644
>> --- a/drivers/clk/rockchip/clk.h
>> +++ b/drivers/clk/rockchip/clk.h
>> @@ -120,6 +120,38 @@ struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
>>                  struct rockchip_pll_rate_table *rate_table,
>>                  spinlock_t *lock);
>>
>> +struct rockchip_cpuclk_clksel {
>> +       int reg;
>> +       u32 val;
>> +};
>> +
>> +#define ROCKCHIP_CPUCLK_NUM_DIVIDERS   2
>> +struct rockchip_cpuclk_rate_table {
>> +       unsigned long prate;
>> +       struct rockchip_cpuclk_clksel divs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
>> +};
>> +
>> +/**
>> + * struct rockchip_cpuclk_reg_data: describes register offsets and masks of the cpuclock
>> + * @core_reg:          register offset of the core settings register
>> + * @div_core_shift:    core divider offset used to divide the pll value
>> + * @div_core_mask:     core divider mask
>> + * @mux_core_shift:    offset of the core multiplexer
>> + */
>> +struct rockchip_cpuclk_reg_data {
>> +       int             core_reg;
>> +       u8              div_core_shift;
>> +       u32             div_core_mask;
>> +       int             mux_core_reg;
>> +       u8              mux_core_shift;
>> +};
>> +
>> +struct clk *rockchip_clk_register_cpuclk(const char *name,
>> +                       const char **parent_names, u8 num_parents,
>> +                       const struct rockchip_cpuclk_reg_data *reg_data,
>> +                       struct rockchip_cpuclk_rate_table *rate_table,
>> +                       void __iomem *reg_base, spinlock_t *lock);
>> +
>>   #define PNAME(x) static const char *x[] __initconst
>>
>>   enum rockchip_clk_branch_type {
>> @@ -329,6 +361,10 @@ void rockchip_clk_register_branches(struct rockchip_clk_branch *clk_list,
>>                                      unsigned int nr_clk);
>>   void rockchip_clk_register_plls(struct rockchip_pll_clock *pll_list,
>>                                  unsigned int nr_pll, int grf_lock_offset);
>> +void rockchip_clk_register_armclk(unsigned int lookup_id, const char *name,
>> +                       const char **parent_names, u8 num_parents,
>> +                       const struct rockchip_cpuclk_reg_data *reg_data,
>> +                       struct rockchip_cpuclk_rate_table *rate_table);
>>   void rockchip_clk_protect_critical(const char *clocks[], int nclocks);
>>
>>   #define ROCKCHIP_SOFTRST_HIWORD_MASK   BIT(0)
>> --
>> 2.0.1
>>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
>
>
>

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Doug Anderson]

Kever and Heiko

On Mon, Sep 15, 2014 at 6:00 PM, Kever Yang <kever.yang@rock-chips.com> wrote:
>>> +       /* select alternate parent */
>>> +       writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
>>> +              cpuclk->reg_base + reg_data->core_reg);
>>
>> In the "alt_prate > ndata->old_rate" case there's a period of time
>> where you can be running super slow.
>>
>> If we start as 126000 and we're going to switch to 594000, we decide
>> we need a divide by 5.  We apply the divide by 5 in one statement and
>> switch to 594MHz in a second statement.  That means there's a very
>> short period of time where we're at 126000 / 5 = 25200.  That's 25MHz.
>>
>> I've found that when I stress out CPUfreq and have a lot of interrupts
>> coming in (like from USB) the my system hangs here.
>>
>> Since the "alt div" and reparenting touch the same register, I think
>> we can do them in a single operation.  That works for me.
>
> Agree, this should be work, the operation for div and parent select for
> arm clk is in the same register in rk3066, rk3188 and rk3288.
>>
>>
>> ...but something isn't adding up for me, so I'm hesitant to suggest
>> this.  Somehow I only end up with the hang here and not down in the
>> post_rate_change().  I'll keep debugging...  It strangely enough seems
>> related to the rockchip_pll_notifier_cb()???
>
> Did you test this on Gerrit 3.14? I think we have a know problem that make
> POST_RATE_CHANGE notifier is not send which has been fixed by Derek.

I accounted for that.  Thanks for the reminder though.

I think I've solved the two separate bugs.  Hopefully Heiko (and you!)
can take a look at my fixes.  The overall summary of what I think was
happening:

1. We were at 126MHz

2. We decided that we wanted to go to 216MHz

3. In prep for changing the ARM PLL, we switched to "slow mode".  AKA:
24MHz.  This happens in a callback.

4. In prep for swtiching to GPLL, we decided that the divider should be "/ 5"

5. We applied "/ 5" to the current PLL (24MHz), giving 4.8MHz


BUG: If we happen to get a USB interrupt here (we get lots and lots
and lots if we have a USB Ethernet adapter in), we're hosed.  We'll
keep getting interrupts faster than we handle them.


6. We quickly switch to GPLL, giving us 594MHz / 5 = 118.8MHz.

7. We switch the PLL to 216MHz

8. We switch out of slow mode.

9. We switch off GPLL, giving us 216MHz / 5 = 43MHz.

10. We remove the divider, giving us 216MHz.

---

With my patches we never run on 24MHz and only ever divide GPLL.  I've
put them on gerrit since I expect Heiko will just fold them in his
patches.

* https://chromium-review.googlesource.com/218432 - FIXUP: clk:
rockchip: add new clock-type for the cpuclk (slow mode fix)

* https://chromium-review.googlesource.com/218433 - FIXUP: clk:
rockchip: add new clock-type for the cpuclk (atomic change, plus ...


...I've also fixed the problem with the common clock framework caching things...


Comments are certainly welcome.  ...or if I'm doing something stupid /
wrong, please tell me.  It's late (for me) and I'm writing this after
drinking a sangria.  ;)


-Doug

[PATCH v2 5/7] clk: rockchip: add new clock-type for the cpuclk

[Karl Palsson]

On Mon, Sep 15, 2014 at 05:49:01PM -0700, Doug Anderson wrote:
> Hi,
> 
> On Mon, Sep 15, 2014 at 4:58 PM, Doug Anderson <dianders@chromium.org> wrote:
> > Heiko,
> >
> > On Fri, Sep 12, 2014 at 3:30 PM, Heiko Stuebner <heiko@sntech.de> wrote:
> >> When changing the armclk on Rockchip SoCs it is supposed to be reparented
> >> to an alternate parent before changing the underlying pll and back after
> >> the change. Additionally there exist clocks that are very tightly bound to
> >> the armclk whose divider values are set according to the armclk rate.
> >>
> >> Add a special clock-type to handle all that. The rate table and divider
> >> values will be supplied from the soc-specific clock controllers.
> >>
> >> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> >> ---
> >>  drivers/clk/rockchip/Makefile  |   1 +
> >>  drivers/clk/rockchip/clk-cpu.c | 316 +++++++++++++++++++++++++++++++++++++++++
> >>  drivers/clk/rockchip/clk.c     |  20 +++
> >>  drivers/clk/rockchip/clk.h     |  36 +++++
> >>  4 files changed, 373 insertions(+)
> >>  create mode 100644 drivers/clk/rockchip/clk-cpu.c
> >>
> >> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
> >> index ee6b077..bd8514d 100644
> >> --- a/drivers/clk/rockchip/Makefile
> >> +++ b/drivers/clk/rockchip/Makefile
> >> @@ -5,6 +5,7 @@
> >>  obj-y  += clk-rockchip.o
> >>  obj-y  += clk.o
> >>  obj-y  += clk-pll.o
> >> +obj-y  += clk-cpu.o
> >>  obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
> >>
> >>  obj-y  += clk-rk3188.o
> >> diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
> >> new file mode 100644
> >> index 0000000..b8382b1
> >> --- /dev/null
> >> +++ b/drivers/clk/rockchip/clk-cpu.c
> >> @@ -0,0 +1,316 @@
> >> +/*
> >> + * Copyright (c) 2014 MundoReader S.L.
> >> + * Author: Heiko Stuebner <heiko@sntech.de>
> >> + *
> >> + * based on clk/samsung/clk-cpu.c
> >> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> >> + * Author: Thomas Abraham <thomas.ab@samsung.com>
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License version 2 as
> >> + * published by the Free Software Foundation.
> >> + *
> >> + * This file contains the utility function to register CPU clock for Samsung
> >> + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a

It might be based on the clk/samsung/clk-cpu.c, as you mentioned above, but
_this_  file doesn't contain samsung exynos code...

Cheers,
Karl P