[PATCH 1/5] clk: mvebu: support for 98DX3236 SoC
Gregory CLEMENT
gregory.clement at free-electrons.com
Wed Jan 4 09:32:08 PST 2017
Hi Chris,
On jeu., déc. 22 2016, Chris Packham <chris.packham at alliedtelesis.co.nz> wrote:
> The 98DX3236, 98DX3336, 98DX4521 and variants have a different TCLK from
> the Armada XP (200MHz vs 250MHz). The CPU core clock is fixed at 800MHz.
>
> The clock gating options are a subset of those on the Armada XP.
>
> The core clock divider is different to the Armada XP also.
This patch looks good, however you should update the device tree binding
documentation too.
Thanks,
Gregory
>
> Signed-off-by: Chris Packham <chris.packham at alliedtelesis.co.nz>
> ---
> drivers/clk/mvebu/Makefile | 2 +-
> drivers/clk/mvebu/armada-xp.c | 42 +++++++
> drivers/clk/mvebu/clk-cpu.c | 33 +++++-
> drivers/clk/mvebu/mv98dx3236-corediv.c | 207 +++++++++++++++++++++++++++++++++
> 4 files changed, 280 insertions(+), 4 deletions(-)
> create mode 100644 drivers/clk/mvebu/mv98dx3236-corediv.c
>
> diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
> index d9ae97fb43c4..6a3681e3d6db 100644
> --- a/drivers/clk/mvebu/Makefile
> +++ b/drivers/clk/mvebu/Makefile
> @@ -9,7 +9,7 @@ obj-$(CONFIG_ARMADA_39X_CLK) += armada-39x.o
> obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-xtal.o
> obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-tbg.o
> obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-periph.o
> -obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o
> +obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o mv98dx3236-corediv.o
> obj-$(CONFIG_ARMADA_AP806_SYSCON) += ap806-system-controller.o
> obj-$(CONFIG_ARMADA_CP110_SYSCON) += cp110-system-controller.o
> obj-$(CONFIG_DOVE_CLK) += dove.o dove-divider.o
> diff --git a/drivers/clk/mvebu/armada-xp.c b/drivers/clk/mvebu/armada-xp.c
> index b3094315a3c0..0413bf8284e0 100644
> --- a/drivers/clk/mvebu/armada-xp.c
> +++ b/drivers/clk/mvebu/armada-xp.c
> @@ -52,6 +52,12 @@ static u32 __init axp_get_tclk_freq(void __iomem *sar)
> return 250000000;
> }
>
> +/* MV98DX3236 TCLK frequency is fixed to 200MHz */
> +static u32 __init mv98dx3236_get_tclk_freq(void __iomem *sar)
> +{
> + return 200000000;
> +}
> +
> static const u32 axp_cpu_freqs[] __initconst = {
> 1000000000,
> 1066000000,
> @@ -89,6 +95,12 @@ static u32 __init axp_get_cpu_freq(void __iomem *sar)
> return cpu_freq;
> }
>
> +/* MV98DX3236 CLK frequency is fixed to 800MHz */
> +static u32 __init mv98dx3236_get_cpu_freq(void __iomem *sar)
> +{
> + return 800000000;
> +}
> +
> static const int axp_nbclk_ratios[32][2] __initconst = {
> {0, 1}, {1, 2}, {2, 2}, {2, 2},
> {1, 2}, {1, 2}, {1, 1}, {2, 3},
> @@ -158,6 +170,14 @@ static const struct coreclk_soc_desc axp_coreclks = {
> .num_ratios = ARRAY_SIZE(axp_coreclk_ratios),
> };
>
> +static const struct coreclk_soc_desc mv98dx3236_coreclks = {
> + .get_tclk_freq = mv98dx3236_get_tclk_freq,
> + .get_cpu_freq = mv98dx3236_get_cpu_freq,
> + .get_clk_ratio = NULL,
> + .ratios = NULL,
> + .num_ratios = 0,
> +};
> +
> /*
> * Clock Gating Control
> */
> @@ -195,6 +215,15 @@ static const struct clk_gating_soc_desc axp_gating_desc[] __initconst = {
> { }
> };
>
> +static const struct clk_gating_soc_desc mv98dx3236_gating_desc[] __initconst = {
> + { "ge1", NULL, 3, 0 },
> + { "ge0", NULL, 4, 0 },
> + { "pex00", NULL, 5, 0 },
> + { "sdio", NULL, 17, 0 },
> + { "xor0", NULL, 22, 0 },
> + { }
> +};
> +
> static void __init axp_clk_init(struct device_node *np)
> {
> struct device_node *cgnp =
> @@ -206,3 +235,16 @@ static void __init axp_clk_init(struct device_node *np)
> mvebu_clk_gating_setup(cgnp, axp_gating_desc);
> }
> CLK_OF_DECLARE(axp_clk, "marvell,armada-xp-core-clock", axp_clk_init);
> +
> +static void __init mv98dx3236_clk_init(struct device_node *np)
> +{
> + struct device_node *cgnp =
> + of_find_compatible_node(NULL, NULL, "marvell,armada-xp-gating-clock");
> +
> + mvebu_coreclk_setup(np, &mv98dx3236_coreclks);
> +
> + if (cgnp)
> + mvebu_clk_gating_setup(cgnp, mv98dx3236_gating_desc);
> +}
> +CLK_OF_DECLARE(mv98dx3236_clk, "marvell,mv98dx3236-core-clock",
> + mv98dx3236_clk_init);
> diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
> index 5837eb8a212f..29f295e7a36b 100644
> --- a/drivers/clk/mvebu/clk-cpu.c
> +++ b/drivers/clk/mvebu/clk-cpu.c
> @@ -165,7 +165,9 @@ static const struct clk_ops cpu_ops = {
> .set_rate = clk_cpu_set_rate,
> };
>
> -static void __init of_cpu_clk_setup(struct device_node *node)
> +/* Add parameter to allow this to support different clock operations. */
> +static void __init _of_cpu_clk_setup(struct device_node *node,
> + const struct clk_ops *cpu_clk_ops)
> {
> struct cpu_clk *cpuclk;
> void __iomem *clock_complex_base = of_iomap(node, 0);
> @@ -218,7 +220,7 @@ static void __init of_cpu_clk_setup(struct device_node *node)
> cpuclk[cpu].hw.init = &init;
>
> init.name = cpuclk[cpu].clk_name;
> - init.ops = &cpu_ops;
> + init.ops = cpu_clk_ops;
> init.flags = 0;
> init.parent_names = &cpuclk[cpu].parent_name;
> init.num_parents = 1;
> @@ -243,5 +245,30 @@ static void __init of_cpu_clk_setup(struct device_node *node)
> iounmap(clock_complex_base);
> }
>
> +/* Use this function to call the generic setup with the correct
> + * clock operation
> + */
> +static void __init of_cpu_clk_setup(struct device_node *node)
> +{
> + _of_cpu_clk_setup(node, &cpu_ops);
> +}
> +
> CLK_OF_DECLARE(armada_xp_cpu_clock, "marvell,armada-xp-cpu-clock",
> - of_cpu_clk_setup);
> + of_cpu_clk_setup);
> +
> +/* Define the clock and operations for the mv98dx3236 - it cannot perform
> + * any operations.
> + */
> +static const struct clk_ops mv98dx3236_cpu_ops = {
> + .recalc_rate = NULL,
> + .round_rate = NULL,
> + .set_rate = NULL,
> +};
> +
> +static void __init of_mv98dx3236_cpu_clk_setup(struct device_node *node)
> +{
> + _of_cpu_clk_setup(node, &mv98dx3236_cpu_ops);
> +}
> +
> +CLK_OF_DECLARE(mv98dx3236_cpu_clock, "marvell,mv98dx3236-cpu-clock",
> + of_mv98dx3236_cpu_clk_setup);
> diff --git a/drivers/clk/mvebu/mv98dx3236-corediv.c b/drivers/clk/mvebu/mv98dx3236-corediv.c
> new file mode 100644
> index 000000000000..3060764a8e5d
> --- /dev/null
> +++ b/drivers/clk/mvebu/mv98dx3236-corediv.c
> @@ -0,0 +1,207 @@
> +/*
> + * MV98DX3236 Core divider clock
> + *
> + * Copyright (C) 2015 Allied Telesis Labs
> + *
> + * Based on armada-xp-corediv.c
> + * Copyright (C) 2015 Marvell
> + *
> + * John Thompson <john.thompson at alliedtelesis.co.nz>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +#include <linux/kernel.h>
> +#include <linux/clk-provider.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include "common.h"
> +
> +#define CORE_CLK_DIV_RATIO_MASK 0xff
> +
> +#define CLK_DIV_RATIO_NAND_MASK 0x0f
> +#define CLK_DIV_RATIO_NAND_OFFSET 6
> +#define CLK_DIV_RATIO_NAND_FORCE_RELOAD_BIT 26
> +
> +#define RATIO_RELOAD_BIT BIT(10)
> +#define RATIO_REG_OFFSET 0x08
> +
> +/*
> + * This structure represents one core divider clock for the clock
> + * framework, and is dynamically allocated for each core divider clock
> + * existing in the current SoC.
> + */
> +struct clk_corediv {
> + struct clk_hw hw;
> + void __iomem *reg;
> + spinlock_t lock;
> +};
> +
> +static struct clk_onecell_data clk_data;
> +
> +
> +#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)
> +
> +static int mv98dx3236_corediv_is_enabled(struct clk_hw *hwclk)
> +{
> + /* Core divider is always active */
> + return 1;
> +}
> +
> +static int mv98dx3236_corediv_enable(struct clk_hw *hwclk)
> +{
> + /* always succeeds */
> + return 0;
> +}
> +
> +static void mv98dx3236_corediv_disable(struct clk_hw *hwclk)
> +{
> + /* can't be disabled so is left alone */
> +}
> +
> +static unsigned long mv98dx3236_corediv_recalc_rate(struct clk_hw *hwclk,
> + unsigned long parent_rate)
> +{
> + struct clk_corediv *corediv = to_corediv_clk(hwclk);
> + u32 reg, div;
> +
> + reg = readl(corediv->reg + RATIO_REG_OFFSET);
> + div = (reg >> CLK_DIV_RATIO_NAND_OFFSET) & CLK_DIV_RATIO_NAND_MASK;
> + return parent_rate / div;
> +}
> +
> +static long mv98dx3236_corediv_round_rate(struct clk_hw *hwclk,
> + unsigned long rate, unsigned long *parent_rate)
> +{
> + /* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
> + u32 div;
> +
> + div = *parent_rate / rate;
> + if (div < 4)
> + div = 4;
> + else if (div > 6)
> + div = 8;
> +
> + return *parent_rate / div;
> +}
> +
> +static int mv98dx3236_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_corediv *corediv = to_corediv_clk(hwclk);
> + unsigned long flags = 0;
> + u32 reg, div;
> +
> + div = parent_rate / rate;
> +
> + spin_lock_irqsave(&corediv->lock, flags);
> +
> + /* Write new divider to the divider ratio register */
> + reg = readl(corediv->reg + RATIO_REG_OFFSET);
> + reg &= ~(CLK_DIV_RATIO_NAND_MASK << CLK_DIV_RATIO_NAND_OFFSET);
> + reg |= (div & CLK_DIV_RATIO_NAND_MASK) << CLK_DIV_RATIO_NAND_OFFSET;
> + writel(reg, corediv->reg + RATIO_REG_OFFSET);
> +
> + /* Set reload-force for this clock */
> + reg = readl(corediv->reg) | BIT(CLK_DIV_RATIO_NAND_FORCE_RELOAD_BIT);
> + writel(reg, corediv->reg);
> +
> + /* Now trigger the clock update */
> + reg = readl(corediv->reg + RATIO_REG_OFFSET) | RATIO_RELOAD_BIT;
> + writel(reg, corediv->reg + RATIO_REG_OFFSET);
> +
> + /*
> + * Wait for clocks to settle down, and then clear all the
> + * ratios request and the reload request.
> + */
> + udelay(1000);
> + reg &= ~(CORE_CLK_DIV_RATIO_MASK | RATIO_RELOAD_BIT);
> + writel(reg, corediv->reg + RATIO_REG_OFFSET);
> + udelay(1000);
> +
> + spin_unlock_irqrestore(&corediv->lock, flags);
> +
> + return 0;
> +}
> +
> +static const struct clk_ops ops = {
> + .enable = mv98dx3236_corediv_enable,
> + .disable = mv98dx3236_corediv_disable,
> + .is_enabled = mv98dx3236_corediv_is_enabled,
> + .recalc_rate = mv98dx3236_corediv_recalc_rate,
> + .round_rate = mv98dx3236_corediv_round_rate,
> + .set_rate = mv98dx3236_corediv_set_rate,
> +};
> +
> +static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
> +{
> + struct clk_init_data init;
> + struct clk_corediv *corediv;
> + struct clk **clks;
> + void __iomem *base;
> + const __be32 *off;
> + const char *parent_name;
> + const char *clk_name;
> + int len;
> + struct device_node *dfx_node;
> +
> + dfx_node = of_parse_phandle(node, "base", 0);
> + if (WARN_ON(!dfx_node))
> + return;
> +
> + off = of_get_property(node, "reg", &len);
> + if (WARN_ON(!off))
> + return;
> +
> + base = of_iomap(dfx_node, 0);
> + if (WARN_ON(!base))
> + return;
> +
> + of_node_put(dfx_node);
> +
> + parent_name = of_clk_get_parent_name(node, 0);
> +
> + clk_data.clk_num = 1;
> +
> + /* clks holds the clock array */
> + clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
> + GFP_KERNEL);
> + if (WARN_ON(!clks))
> + goto err_unmap;
> + /* corediv holds the clock specific array */
> + corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
> + GFP_KERNEL);
> + if (WARN_ON(!corediv))
> + goto err_free_clks;
> +
> + spin_lock_init(&corediv->lock);
> +
> + of_property_read_string_index(node, "clock-output-names",
> + 0, &clk_name);
> +
> + init.num_parents = 1;
> + init.parent_names = &parent_name;
> + init.name = clk_name;
> + init.ops = &ops;
> + init.flags = 0;
> +
> + corediv[0].reg = (void *)((int)base + be32_to_cpu(*off));
> + corediv[0].hw.init = &init;
> +
> + clks[0] = clk_register(NULL, &corediv[0].hw);
> + WARN_ON(IS_ERR(clks[0]));
> +
> + clk_data.clks = clks;
> + of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
> + return;
> +
> +err_free_clks:
> + kfree(clks);
> +err_unmap:
> + iounmap(base);
> +}
> +
> +CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
> + mv98dx3236_corediv_clk_init);
> --
> 2.11.0.24.ge6920cf
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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