Subject: [PATCH v2 2/3] clk: add Dove PLL divider support for GPU, VMeta and AXI clocks

From: [email-masked] (Andrew Lunn)
Date: Mon, 7 Dec 2015 02:24:37 +0100

On Sun, Dec 06, 2015 at 11:28:32PM +0000, Russell King wrote:
> Add support for the Dove PLL dividers, which are used to generate the
> clocks for the AXI bus, as well as the GPU and VMeta peripherals.
> 
> Signed-off-by: Russell King <[email-masked]>

Hi Russell

Thanks for the fix.

Acked-by: Andrew Lunn <[email-masked]>

       Andrew

> ---
>  drivers/clk/mvebu/Makefile       |   2 +-
>  drivers/clk/mvebu/dove-divider.c | 262 +++++++++++++++++++++++++++++++++++++++
>  drivers/clk/mvebu/dove.c         |   6 +
>  3 files changed, 269 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/mvebu/dove-divider.c
> 
> diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
> index 645ac7ea3565..8866115486f7 100644
> --- a/drivers/clk/mvebu/Makefile
> +++ b/drivers/clk/mvebu/Makefile
> @@ -7,6 +7,6 @@ obj-$(CONFIG_ARMADA_375_CLK)	+= armada-375.o
>  obj-$(CONFIG_ARMADA_38X_CLK)	+= armada-38x.o
>  obj-$(CONFIG_ARMADA_39X_CLK)	+= armada-39x.o
>  obj-$(CONFIG_ARMADA_XP_CLK)	+= armada-xp.o
> -obj-$(CONFIG_DOVE_CLK)		+= dove.o
> +obj-$(CONFIG_DOVE_CLK)		+= dove.o dove-divider.o
>  obj-$(CONFIG_KIRKWOOD_CLK)	+= kirkwood.o
>  obj-$(CONFIG_ORION_CLK)		+= orion.o
> diff --git a/drivers/clk/mvebu/dove-divider.c b/drivers/clk/mvebu/dove-divider.c
> new file mode 100644
> index 000000000000..d5c5bfa35a5a
> --- /dev/null
> +++ b/drivers/clk/mvebu/dove-divider.c
> @@ -0,0 +1,262 @@
> +/*
> + * Marvell Dove PMU Core PLL divider driver
> + *
> + * Cleaned up by substantially rewriting, and converted to DT by
> + * Russell King.  Origin is not known.
> + */
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +#include "dove-divider.h"
> +
> +struct dove_clk {
> +	const char *name;
> +	struct clk_hw hw;
> +	void __iomem *base;
> +	spinlock_t *lock;
> +	u8 div_bit_start;
> +	u8 div_bit_end;
> +	u8 div_bit_load;
> +	u8 div_bit_size;
> +	u32 *divider_table;
> +};
> +
> +enum {
> +	DIV_CTRL0 = 0,
> +	DIV_CTRL1 = 4,
> +	DIV_CTRL1_N_RESET_MASK = BIT(10),
> +};
> +
> +#define to_dove_clk(hw) container_of(hw, struct dove_clk, hw)
> +
> +static void dove_load_divider(void __iomem *base, u32 val, u32 mask, u32 load)
> +{
> +	u32 v;
> +
> +	v = readl_relaxed(base + DIV_CTRL1) | DIV_CTRL1_N_RESET_MASK;
> +	writel_relaxed(v, base + DIV_CTRL1);
> +
> +	v = (readl_relaxed(base + DIV_CTRL0) & ~(mask | load)) | val;
> +	writel_relaxed(v, base + DIV_CTRL0);
> +	writel_relaxed(v | load, base + DIV_CTRL0);
> +	ndelay(250);
> +	writel_relaxed(v, base + DIV_CTRL0);
> +}
> +
> +static unsigned int dove_get_divider(struct dove_clk *dc)
> +{
> +	unsigned int divider;
> +	u32 val;
> +
> +	val = readl_relaxed(dc->base + DIV_CTRL0);
> +	val >>= dc->div_bit_start;
> +
> +	divider = val & ~(~0 << dc->div_bit_size);
> +
> +	if (dc->divider_table)
> +		divider = dc->divider_table[divider];
> +
> +	return divider;
> +}
> +
> +static int dove_calc_divider(const struct dove_clk *dc, unsigned long rate,
> +			     unsigned long parent_rate, bool set)
> +{
> +	unsigned int divider, max;
> +
> +	divider = DIV_ROUND_CLOSEST(parent_rate, rate);
> +
> +	if (dc->divider_table) {
> +		unsigned int i;
> +
> +		for (i = 0; dc->divider_table[i]; i++)
> +			if (divider == dc->divider_table[i]) {
> +				divider = i;
> +				break;
> +			}
> +
> +		if (!dc->divider_table[i])
> +			return -EINVAL;
> +	} else {
> +		max = 1 << dc->div_bit_size;
> +
> +		if (set && (divider == 0 || divider >= max))
> +			return -EINVAL;
> +		if (divider >= max)
> +			divider = max - 1;
> +		else if (divider == 0)
> +			divider = 1;
> +	}
> +
> +	return divider;
> +}
> +
> +static unsigned long dove_recalc_rate(struct clk_hw *hw, unsigned long parent)
> +{
> +	struct dove_clk *dc = to_dove_clk(hw);
> +	unsigned int divider = dove_get_divider(dc);
> +	unsigned long rate = DIV_ROUND_CLOSEST(parent, divider);
> +
> +	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
> +		 __func__, dc->name, divider, parent, rate);
> +
> +	return rate;
> +}
> +
> +static long dove_round_rate(struct clk_hw *hw, unsigned long rate,
> +			    unsigned long *parent)
> +{
> +	struct dove_clk *dc = to_dove_clk(hw);
> +	unsigned long parent_rate = *parent;
> +	int divider;
> +
> +	divider = dove_calc_divider(dc, rate, parent_rate, false);
> +	if (divider < 0)
> +		return divider;
> +
> +	rate = DIV_ROUND_CLOSEST(parent_rate, divider);
> +
> +	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
> +		 __func__, dc->name, divider, parent_rate, rate);
> +
> +	return rate;
> +}
> +
> +static int dove_set_clock(struct clk_hw *hw, unsigned long rate,
> +			  unsigned long parent_rate)
> +{
> +	struct dove_clk *dc = to_dove_clk(hw);
> +	u32 mask, load, div;
> +	int divider;
> +
> +	divider = dove_calc_divider(dc, rate, parent_rate, true);
> +	if (divider < 0)
> +		return divider;
> +
> +	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
> +		 __func__, dc->name, divider, parent_rate, rate);
> +
> +	div = (u32)divider << dc->div_bit_start;
> +	mask = ~(~0 << dc->div_bit_size) << dc->div_bit_start;
> +	load = BIT(dc->div_bit_load);
> +
> +	spin_lock(dc->lock);
> +	dove_load_divider(dc->base, div, mask, load);
> +	spin_unlock(dc->lock);
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops dove_divider_ops = {
> +	.set_rate	= dove_set_clock,
> +	.round_rate	= dove_round_rate,
> +	.recalc_rate	= dove_recalc_rate,
> +};
> +
> +static struct clk *clk_register_dove_divider(struct device *dev,
> +	struct dove_clk *dc, const char **parent_names, size_t num_parents,
> +	void __iomem *base)
> +{
> +	char name[32];
> +	struct clk_init_data init = {
> +		.name = name,
> +		.ops = &dove_divider_ops,
> +		.parent_names = parent_names,
> +		.num_parents = num_parents,
> +	};
> +
> +	strlcpy(name, dc->name, sizeof(name));
> +
> +	dc->hw.init = &init;
> +	dc->base = base;
> +	dc->div_bit_size = dc->div_bit_end - dc->div_bit_start + 1;
> +
> +	return clk_register(dev, &dc->hw);
> +}
> +
> +static DEFINE_SPINLOCK(dove_divider_lock);
> +
> +static u32 axi_divider[] = {-1, 2, 1, 3, 4, 6, 5, 7, 8, 10, 9, 0};
> +
> +static struct dove_clk dove_hw_clocks[4] = {
> +	{
> +		.name = "axi",
> +		.lock = &dove_divider_lock,
> +		.div_bit_start = 1,
> +		.div_bit_end = 6,
> +		.div_bit_load = 7,
> +		.divider_table = axi_divider,
> +	}, {
> +		.name = "gpu",
> +		.lock = &dove_divider_lock,
> +		.div_bit_start = 8,
> +		.div_bit_end = 13,
> +		.div_bit_load = 14,
> +	}, {
> +		.name = "vmeta",
> +		.lock = &dove_divider_lock,
> +		.div_bit_start = 15,
> +		.div_bit_end = 20,
> +		.div_bit_load = 21,
> +	}, {
> +		.name = "lcd",
> +		.lock = &dove_divider_lock,
> +		.div_bit_start = 22,
> +		.div_bit_end = 27,
> +		.div_bit_load = 28,
> +	},
> +};
> +
> +static const char *core_pll[] = {
> +	"core-pll",
> +};
> +
> +static int dove_divider_init(struct device *dev, void __iomem *base,
> +	struct clk **clks)
> +{
> +	struct clk *clk;
> +	int i;
> +
> +	/*
> +	 * Create the core PLL clock.  We treat this as a fixed rate
> +	 * clock as we don't know any better, and documentation is sparse.
> +	 */
> +	clk = clk_register_fixed_rate(dev, core_pll[0], NULL, CLK_IS_ROOT,
> +				      2000000000UL);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	for (i = 0; i < ARRAY_SIZE(dove_hw_clocks); i++)
> +		clks[i] = clk_register_dove_divider(dev, &dove_hw_clocks[i],
> +						    core_pll,
> +						    ARRAY_SIZE(core_pll), base);
> +
> +	return 0;
> +}
> +
> +static struct clk *dove_divider_clocks[4];
> +
> +static struct clk_onecell_data dove_divider_data = {
> +	.clks = dove_divider_clocks,
> +	.clk_num = ARRAY_SIZE(dove_divider_clocks),
> +};
> +
> +void __init dove_divider_clk_init(struct device_node *np)
> +{
> +	void *base;
> +
> +	base = of_iomap(np, 0);
> +	if (WARN_ON(!base))
> +		return;
> +
> +	if (WARN_ON(dove_divider_init(NULL, base, dove_divider_clocks))) {
> +		iounmap(base);
> +		return;
> +	}
> +
> +	of_clk_add_provider(np, of_clk_src_onecell_get, &dove_divider_data);
> +}
> diff --git a/drivers/clk/mvebu/dove.c b/drivers/clk/mvebu/dove.c
> index b8c2424ac926..59fad9546c84 100644
> --- a/drivers/clk/mvebu/dove.c
> +++ b/drivers/clk/mvebu/dove.c
> @@ -17,6 +17,7 @@
>  #include <linux/io.h>
>  #include <linux/of.h>
>  #include "common.h"
> +#include "dove-divider.h"
>  
>  /*
>   * Core Clocks
> @@ -184,9 +185,14 @@ static void __init dove_clk_init(struct device_node *np)
>  {
>  	struct device_node *cgnp =
>  		of_find_compatible_node(NULL, NULL, "marvell,dove-gating-clock");
> +	struct device_node *ddnp =
> +		of_find_compatible_node(NULL, NULL, "marvell,dove-divider-clock");
>  
>  	mvebu_coreclk_setup(np, &dove_coreclks);
>  
> +	if (ddnp)
> +		dove_divider_clk_init(ddnp);
> +
>  	if (cgnp)
>  		mvebu_clk_gating_setup(cgnp, dove_gating_desc);
>  }
> -- 
> 2.1.0
>