Re: [PATCH v4] clk: axs10x: introduce AXS10X pll driver

From: Eugeniy Paltsev
Date: Wed Jul 05 2017 - 07:24:10 EST

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On Wed, 2017-06-21 at 22:16 +0300, Eugeniy Paltsev wrote:

Hi Stephen, Michael,

Maybe you have any comments or remarks about this patch? And if you
don't could you please apply it.

Thanks a lot!

> AXS10X boards manages it's clocks using various PLLs. These PLL has
> same
> dividers and corresponding control registers mapped to different
> addresses.
> So we add one common driver for such PLLs.
>
> Each PLL on AXS10X board consist of three dividers: IDIV, FBDIV and
> ODIV. Output clock value is managed using these dividers.
>
> We add pre-defined tables with supported rate values and appropriate
> configurations of IDIV, FBDIV and ODIV for each value.
>
> As of today we add support for PLLs that generate clock for the
> following devices:
> Â* ARC core on AXC CPU tiles.
> Â* ARC PGU on ARC SDP Mainboard.
> and more to come later.
>
> By this patch we add support for two plls (arc core pll and pgu pll),
> so we had to use two different init types: CLK_OF_DECLARE for arc
> core pll and
> regular probing for pgu pll.
>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> Acked-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
>
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
> Signed-off-by: Vlad Zakharov <vzakhar@xxxxxxxxxxxx>
> Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
> ---
> Changes for v4:
> Â - fix resource freing after error in of_axs10x_pll_clk_setup
> Â - add axs10x* prefix to main functions and structures
> Â - style fixies
>
> Changes for v2..v3:
> Â - replaced complex data structures with simple cfg tables
> Â - replaced non-hw based provider and clk registration functions
> with hw-based
> Â - fixed typos and minor code styling issues
>
> Â.../devicetree/bindings/clock/snps,pll-clock.txtÂÂÂ|ÂÂ28 ++
> ÂMAINTAINERSÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂ6 +
> Âdrivers/clk/axs10x/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ|ÂÂÂ1 +
> Âdrivers/clk/axs10x/pll_clock.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ| 344
> +++++++++++++++++++++
> Â4 files changed, 379 insertions(+)
> Âcreate mode 100644 Documentation/devicetree/bindings/clock/snps,pll-
> clock.txt
> Âcreate mode 100644 drivers/clk/axs10x/pll_clock.c
>
> diff --git a/Documentation/devicetree/bindings/clock/snps,pll-
> clock.txt b/Documentation/devicetree/bindings/clock/snps,pll-
> clock.txt
> new file mode 100644
> index 0000000..11fe487
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/snps,pll-clock.txt
> @@ -0,0 +1,28 @@
> +Binding for the AXS10X Generic PLL clock
> +
> +This binding uses the common clock binding[1].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Required properties:
> +- compatible: should be "snps,axs10x-<name>-pll-clock"
> +ÂÂ"snps,axs10x-arc-pll-clock"
> +ÂÂ"snps,axs10x-pgu-pll-clock"
> +- reg: should always contain 2 pairs address - length: first for PLL
> config
> +registers and second for corresponding LOCK CGU register.
> +- clocks: shall be the input parent clock phandle for the PLL.
> +- #clock-cells: from common clock binding; Should always be set to
> 0.
> +
> +Example:
> + input-clk: input-clk {
> + clock-frequency = <33333333>;
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + };
> +
> + core-clk: core-clk@80 {
> + compatible = "snps,axs10x-arc-pll-clock";
> + reg = <0x80 0x10>, <0x100 0x10>;
> + #clock-cells = <0>;
> + clocks = <&input-clk>;
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6b4395c..c5219d6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12560,6 +12560,12 @@ F: arch/arc/plat-axs10x
> ÂF: arch/arc/boot/dts/ax*
> ÂF: Documentation/devicetree/bindings/arc/axs10*
> Â
> +SYNOPSYS ARC SDP clock driver
> +M: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx>
> +S: Supported
> +F: drivers/clk/axs10x/*
> +F: Documentation/devicetree/bindings/clock/snps,pll-clock.txt
> +
> ÂSYSTEM CONFIGURATION (SYSCON)
> ÂM: Lee Jones <lee.jones@xxxxxxxxxx>
> ÂM: Arnd Bergmann <arnd@xxxxxxxx>
> diff --git a/drivers/clk/axs10x/Makefile
> b/drivers/clk/axs10x/Makefile
> index 01996b8..d747dea 100644
> --- a/drivers/clk/axs10x/Makefile
> +++ b/drivers/clk/axs10x/Makefile
> @@ -1 +1,2 @@
> Âobj-y += i2s_pll_clock.o
> +obj-y += pll_clock.o
> diff --git a/drivers/clk/axs10x/pll_clock.c
> b/drivers/clk/axs10x/pll_clock.c
> new file mode 100644
> index 0000000..69f72ac
> --- /dev/null
> +++ b/drivers/clk/axs10x/pll_clock.c
> @@ -0,0 +1,344 @@
> +/*
> + * Synopsys AXS10X SDP Generic PLL clock driver
> + *
> + * Copyright (C) 2017 Synopsys
> + *
> + * 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/platform_device.h>
> +#include <linux/module.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/device.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +
> +/* PLL registers addresses */
> +#define PLL_REG_IDIV 0x0
> +#define PLL_REG_FBDIV 0x4
> +#define PLL_REG_ODIV 0x8
> +
> +/*
> + * Bit fields of the PLL IDIV/FBDIV/ODIV registers:
> +
> *ÂÂ__________________________________________________________________
> ______
> + *
> |31ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ15|ÂÂÂÂ14ÂÂÂÂ|ÂÂÂ13ÂÂÂ|ÂÂ12ÂÂ|11ÂÂÂÂÂÂÂÂÂ6|5ÂÂÂÂÂÂ
> ÂÂÂ0|
> + * |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|
> --LOWTIME--|
> + *
> |____________________|__________|________|______|____________|_______
> ____|
> + *
> + * Following macros determine the way of access to these registers
> + * They should be set up only using the macros.
> + * reg should be an u32 variable.
> + */
> +
> +#define PLL_REG_GET_LOW(reg) \
> + (((reg) & (0x3F << 0)) >> 0)
> +#define PLL_REG_GET_HIGH(reg) \
> + (((reg) & (0x3F << 6)) >> 6)
> +#define PLL_REG_GET_EDGE(reg) \
> + (((reg) & (BIT(12))) ? 1 : 0)
> +#define PLL_REG_GET_BYPASS(reg) \
> + (((reg) & (BIT(13))) ? 1 : 0)
> +#define PLL_REG_GET_NOUPD(reg) \
> + (((reg) & (BIT(14))) ? 1 : 0)
> +#define PLL_REG_GET_PAD(reg) \
> + (((reg) & (0x1FFFF << 15)) >> 15)
> +
> +#define PLL_REG_SET_LOW(reg, value) \
> + { reg |= (((value) & 0x3F) << 0); }
> +#define PLL_REG_SET_HIGH(reg, value) \
> + { reg |= (((value) & 0x3F) << 6); }
> +#define PLL_REG_SET_EDGE(reg, value) \
> + { reg |= (((value) & 0x01) << 12); }
> +#define PLL_REG_SET_BYPASS(reg, value) \
> + { reg |= (((value) & 0x01) << 13); }
> +#define PLL_REG_SET_NOUPD(reg, value) \
> + { reg |= (((value) & 0x01) << 14); }
> +#define PLL_REG_SET_PAD(reg, value) \
> + { reg |= (((value) & 0x1FFFF) << 15); }
> +
> +#define PLL_LOCK BIT(0)
> +#define PLL_ERROR BIT(1)
> +#define PLL_MAX_LOCK_TIME 100 /* 100 us */
> +
> +struct axs10x_pll_cfg {
> + u32 rate;
> + u32 idiv;
> + u32 fbdiv;
> + u32 odiv;
> +};
> +
> +static const struct axs10x_pll_cfg arc_pll_cfg[] = {
> + { 33333333,ÂÂ1, 1,ÂÂ1 },
> + { 50000000,ÂÂ1, 30, 20 },
> + { 75000000,ÂÂ2, 45, 10 },
> + { 90000000,ÂÂ2, 54, 10 },
> + { 100000000, 1, 30, 10 },
> + { 125000000, 2, 45, 6 },
> + {}
> +};
> +
> +static const struct axs10x_pll_cfg pgu_pll_cfg[] = {
> + { 25200000, 1, 84, 90 },
> + { 50000000, 1, 100, 54 },
> + { 74250000, 1, 44, 16 },
> + {}
> +};
> +
> +struct axs10x_pll_clk {
> + struct clk_hw hw;
> + void __iomem *base;
> + void __iomem *lock;
> + const struct axs10x_pll_cfg *pll_cfg;
> + struct device *dev;
> +};
> +
> +static inline void axs10x_pll_write(struct axs10x_pll_clk *clk, u32
> reg,
> + ÂÂÂÂu32 val)
> +{
> + iowrite32(val, clk->base + reg);
> +}
> +
> +static inline u32 axs10x_pll_read(struct axs10x_pll_clk *clk, u32
> reg)
> +{
> + return ioread32(clk->base + reg);
> +}
> +
> +static inline struct axs10x_pll_clk *to_axs10x_pll_clk(struct clk_hw
> *hw)
> +{
> + return container_of(hw, struct axs10x_pll_clk, hw);
> +}
> +
> +static inline u32 axs10x_div_get_value(u32 reg)
> +{
> + if (PLL_REG_GET_BYPASS(reg))
> + return 1;
> +
> + return PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg);
> +}
> +
> +static inline u32 axs10x_encode_div(unsigned int id, int upd)
> +{
> + u32 div = 0;
> +
> + PLL_REG_SET_LOW(div, (id % 2 == 0) ? id >> 1 : (id >> 1) +
> 1);
> + PLL_REG_SET_HIGH(div, id >> 1);
> + PLL_REG_SET_EDGE(div, id % 2);
> + PLL_REG_SET_BYPASS(div, id == 1 ? 1 : 0);
> + PLL_REG_SET_NOUPD(div, !upd);
> +
> + return div;
> +}
> +
> +static unsigned long axs10x_pll_recalc_rate(struct clk_hw *hw,
> + ÂÂÂÂunsigned long
> parent_rate)
> +{
> + u64 rate;
> + u32 idiv, fbdiv, odiv;
> + struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
> +
> + idiv = axs10x_div_get_value(axs10x_pll_read(clk,
> PLL_REG_IDIV));
> + fbdiv = axs10x_div_get_value(axs10x_pll_read(clk,
> PLL_REG_FBDIV));
> + odiv = axs10x_div_get_value(axs10x_pll_read(clk,
> PLL_REG_ODIV));
> +
> + rate = (u64)parent_rate * fbdiv;
> + do_div(rate, idiv * odiv);
> +
> + return rate;
> +}
> +
> +static long axs10x_pll_round_rate(struct clk_hw *hw, unsigned long
> rate,
> + ÂÂunsigned long *prate)
> +{
> + int i;
> + long best_rate;
> + struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
> + const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
> +
> + if (pll_cfg[0].rate == 0)
> + return -EINVAL;
> +
> + best_rate = pll_cfg[0].rate;
> +
> + for (i = 1; pll_cfg[i].rate != 0; i++) {
> + if (abs(rate - pll_cfg[i].rate) < abs(rate -
> best_rate))
> + best_rate = pll_cfg[i].rate;
> + }
> +
> + return best_rate;
> +}
> +
> +static int axs10x_pll_set_rate(struct clk_hw *hw, unsigned long
> rate,
> + ÂÂÂÂÂÂÂunsigned long parent_rate)
> +{
> + int i;
> + struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
> + const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
> +
> + for (i = 0; pll_cfg[i].rate != 0; i++) {
> + if (pll_cfg[i].rate == rate) {
> + axs10x_pll_write(clk, PLL_REG_IDIV,
> + Âaxs10x_encode_div(pll_cfg[i
> ].idiv, 0));
> + axs10x_pll_write(clk, PLL_REG_FBDIV,
> + Âaxs10x_encode_div(pll_cfg[i
> ].fbdiv, 0));
> + axs10x_pll_write(clk, PLL_REG_ODIV,
> + Âaxs10x_encode_div(pll_cfg[i
> ].odiv, 1));
> +
> + /*
> + Â* Wait until CGU relocks and check error
> status.
> + Â* If after timeout CGU is unlocked yet
> return error
> + Â*/
> + udelay(PLL_MAX_LOCK_TIME);
> + if (!(ioread32(clk->lock) & PLL_LOCK))
> + return -ETIMEDOUT;
> +
> + if (ioread32(clk->lock) & PLL_ERROR)
> + return -EINVAL;
> +
> + return 0;
> + }
> + }
> +
> + dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n",
> rate,
> + parent_rate);
> + return -EINVAL;
> +}
> +
> +static const struct clk_ops axs10x_pll_ops = {
> + .recalc_rate = axs10x_pll_recalc_rate,
> + .round_rate = axs10x_pll_round_rate,
> + .set_rate = axs10x_pll_set_rate,
> +};
> +
> +static int axs10x_pll_clk_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + const char *parent_name;
> + struct axs10x_pll_clk *pll_clk;
> + struct resource *mem;
> + struct clk_init_data init = { };
> + int ret;
> +
> + pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
> + if (!pll_clk)
> + return -ENOMEM;
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + pll_clk->base = devm_ioremap_resource(dev, mem);
> + if (IS_ERR(pll_clk->base))
> + return PTR_ERR(pll_clk->base);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + pll_clk->lock = devm_ioremap_resource(dev, mem);
> + if (IS_ERR(pll_clk->lock))
> + return PTR_ERR(pll_clk->lock);
> +
> + init.name = dev->of_node->name;
> + init.ops = &axs10x_pll_ops;
> + parent_name = of_clk_get_parent_name(dev->of_node, 0);
> + init.parent_names = &parent_name;
> + init.num_parents = 1;
> + pll_clk->hw.init = &init;
> + pll_clk->dev = dev;
> + pll_clk->pll_cfg = of_device_get_match_data(dev);
> +
> + if (!pll_clk->pll_cfg) {
> + dev_err(dev, "No OF match data provided\n");
> + return -EINVAL;
> + }
> +
> + ret = devm_clk_hw_register(dev, &pll_clk->hw);
> + if (ret) {
> + dev_err(dev, "failed to register %s clock\n",
> init.name);
> + return ret;
> + }
> +
> + return of_clk_add_hw_provider(dev->of_node,
> of_clk_hw_simple_get,
> + &pll_clk->hw);
> +}
> +
> +static int axs10x_pll_clk_remove(struct platform_device *pdev)
> +{
> + of_clk_del_provider(pdev->dev.of_node);
> + return 0;
> +}
> +
> +static void __init of_axs10x_pll_clk_setup(struct device_node *node)
> +{
> + const char *parent_name;
> + struct axs10x_pll_clk *pll_clk;
> + struct clk_init_data init = { };
> + int ret;
> +
> + pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
> + if (!pll_clk)
> + return;
> +
> + pll_clk->base = of_iomap(node, 0);
> + if (!pll_clk->base) {
> + pr_err("failed to map pll div registers\n");
> + goto err_free_pll_clk;
> + }
> +
> + pll_clk->lock = of_iomap(node, 1);
> + if (!pll_clk->lock) {
> + pr_err("failed to map pll lock register\n");
> + goto err_unmap_base;
> + }
> +
> + init.name = node->name;
> + init.ops = &axs10x_pll_ops;
> + parent_name = of_clk_get_parent_name(node, 0);
> + init.parent_names = &parent_name;
> + init.num_parents = parent_name ? 1 : 0;
> + pll_clk->hw.init = &init;
> + pll_clk->pll_cfg = arc_pll_cfg;
> +
> + ret = clk_hw_register(NULL, &pll_clk->hw);
> + if (ret) {
> + pr_err("failed to register %s clock\n", node->name);
> + goto err_unmap_lock;
> + }
> +
> + ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get,
> &pll_clk->hw);
> + if (ret) {
> + pr_err("failed to add hw provider for %s clock\n",
> node->name);
> + goto err_unmap_lock;
> + }
> +
> + return;
> +
> +err_unmap_lock:
> + iounmap(pll_clk->lock);
> +err_unmap_base:
> + iounmap(pll_clk->base);
> +err_free_pll_clk:
> + kfree(pll_clk);
> +}
> +CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock",
> + ÂÂÂÂÂÂÂof_axs10x_pll_clk_setup);
> +
> +static const struct of_device_id axs10x_pll_clk_id[] = {
> + { .compatible = "snps,axs10x-pgu-pll-clock", .data =
> &pgu_pll_cfg},
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, axs10x_pll_clk_id);
> +
> +static struct platform_driver axs10x_pll_clk_driver = {
> + .driver = {
> + .name = "axs10x-pll-clock",
> + .of_match_table = axs10x_pll_clk_id,
> + },
> + .probe = axs10x_pll_clk_probe,
> + .remove = axs10x_pll_clk_remove,
> +};
> +builtin_platform_driver(axs10x_pll_clk_driver);
> +
> +MODULE_AUTHOR("Vlad Zakharov <vzakhar@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
> +MODULE_LICENSE("GPL v2");
--
ÂEugeniy Paltsev

Next message: Arvind Yadav: "[PATCH] input: raydium_i2c_ts: constify attribute_group structures."
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