[PATCH v2] clk/axs10x: introduce AXS10X pll driver
Vlad Zakharov
Vladislav.Zakharov at synopsys.com
Fri Mar 3 05:18:34 PST 2017
Hi Michael, Stephen,
On Tue, 2017-02-21 at 16:11 +0300, Vlad Zakharov wrote:
> 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:
> * ARC core on AXC CPU tiles.
> * ARC PGU on ARC SDP Mainboard.
> and more to come later.
>
> Acked-by: Rob Herring <robh at kernel.org>
> Signed-off-by: Vlad Zakharov <vzakhar at synopsys.com>
> Signed-off-by: Jose Abreu <joabreu at synopsys.com>
> Cc: Michael Turquette <mturquette at baylibre.com>
> Cc: Stephen Boyd <sboyd at codeaurora.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> ---
> Cc: Rob Herring <robh at kernel.org>
> Changes v1..v2
> - Replace '_' with '-' in device tree nodes
>
> .../devicetree/bindings/clock/snps,pll-clock.txt | 28 ++
> MAINTAINERS | 6 +
> drivers/clk/axs10x/Makefile | 1 +
> drivers/clk/axs10x/pll_clock.c | 384 +++++++++++++++++++++
> 4 files changed, 419 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/clock/snps,pll-clock.txt
> create 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..5706246
> --- /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"
> + "snps,axs10x-arc-pll-clock"
> + "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 at 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 3960e7f..5805833 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11910,6 +11910,12 @@ F: arch/arc/plat-axs10x
> F: arch/arc/boot/dts/ax*
> F: Documentation/devicetree/bindings/arc/axs10*
>
> +SYNOPSYS ARC SDP clock driver
> +M: Vlad Zakharov <vzakhar at synopsys.com>
> +S: Supported
> +F: drivers/clk/axs10x/*
> +F: Documentation/devicetree/bindings/clock/snps,pll-clock.txt
> +
> SYSTEM CONFIGURATION (SYSCON)
> M: Lee Jones <lee.jones at linaro.org>
> M: Arnd Bergmann <arnd at arndb.de>
> 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 @@
> obj-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..784a0a2
> --- /dev/null
> +++ b/drivers/clk/axs10x/pll_clock.c
> @@ -0,0 +1,384 @@
> +/*
> + * 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:
> + * ________________________________________________________________________
> + * |31 15| 14 | 13 | 12 |11 6|5 0|
> + * |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|--LOWTIME--|
> + * |____________________|__________|________|______|____________|___________|
> + *
> + * Following macros detirmine the way of access to these registers
> + * They should be set up only using the macros.
> + * reg should be and uint32_t 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 0x1
> +#define PLL_MAX_LOCK_TIME 100 /* 100 us */
> +
> +struct pll_cfg {
> + u32 rate;
> + u32 idiv;
> + u32 fbdiv;
> + u32 odiv;
> +};
> +
> +struct pll_of_table {
> + unsigned long prate;
> + struct pll_cfg *pll_cfg_table;
> +};
> +
> +struct pll_of_data {
> + struct pll_of_table *pll_table;
> +};
> +
> +static struct pll_of_data pgu_pll_data = {
> + .pll_table = (struct pll_of_table []){
> + {
> + .prate = 27000000,
> + .pll_cfg_table = (struct pll_cfg []){
> + { 25200000, 1, 84, 90 },
> + { 50000000, 1, 100, 54 },
> + { 74250000, 1, 44, 16 },
> + { },
> + },
> + },
> + /* Used as list limiter */
> + { },
> + },
> +};
> +
> +static struct pll_of_data arc_pll_data = {
> + .pll_table = (struct pll_of_table []){
> + {
> + .prate = 33333333,
> + .pll_cfg_table = (struct pll_cfg []){
> + { 33333333, 1, 1, 1 },
> + { 50000000, 1, 30, 20 },
> + { 75000000, 2, 45, 10 },
> + { 90000000, 2, 54, 10 },
> + { 100000000, 1, 30, 10 },
> + { 125000000, 2, 45, 6 },
> + { },
> + },
> + },
> + /* Used as list limiter */
> + { },
> + },
> +};
> +
> +struct pll_clk {
> + void __iomem *base;
> + void __iomem *lock;
> + const struct pll_of_data *pll_data;
> + struct clk_hw hw;
> + struct device *dev;
> +};
> +
> +static inline void pll_write(struct pll_clk *clk, unsigned int reg,
> + unsigned int val)
> +{
> + iowrite32(val, clk->base + reg);
> +}
> +
> +static inline u32 pll_read(struct pll_clk *clk,
> + unsigned int reg)
> +{
> + return ioread32(clk->base + reg);
> +}
> +
> +static inline struct pll_clk *to_pll_clk(struct clk_hw *hw)
> +{
> + return container_of(hw, struct pll_clk, hw);
> +}
> +
> +static inline u32 div_get_value(unsigned int reg)
> +{
> + if (PLL_REG_GET_BYPASS(reg))
> + return 1;
> +
> + return (PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg));
> +}
> +
> +static inline u32 encode_div(unsigned int id, int upd)
> +{
> + uint32_t 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 const struct pll_cfg *pll_get_cfg(unsigned long prate,
> + const struct pll_of_table *pll_table)
> +{
> + int i;
> +
> + for (i = 0; pll_table[i].prate != 0; i++)
> + if (pll_table[i].prate == prate)
> + return pll_table[i].pll_cfg_table;
> +
> + return NULL;
> +}
> +
> +static unsigned long pll_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + u64 rate;
> + u32 idiv, fbdiv, odiv;
> + struct pll_clk *clk = to_pll_clk(hw);
> +
> + idiv = div_get_value(pll_read(clk, PLL_REG_IDIV));
> + fbdiv = div_get_value(pll_read(clk, PLL_REG_FBDIV));
> + odiv = div_get_value(pll_read(clk, PLL_REG_ODIV));
> +
> + rate = (u64)parent_rate * fbdiv;
> + do_div(rate, idiv * odiv);
> +
> + return (unsigned long)rate;
> +}
> +
> +static long pll_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *prate)
> +{
> + int i;
> + long best_rate;
> + struct pll_clk *clk = to_pll_clk(hw);
> + const struct pll_cfg *pll_cfg = pll_get_cfg(*prate,
> + clk->pll_data->pll_table);
> +
> + if (!pll_cfg) {
> + dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
> + return -EINVAL;
> + }
> +
> + 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 pll_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + int i;
> + struct pll_clk *clk = to_pll_clk(hw);
> + const struct pll_cfg *pll_cfg = pll_get_cfg(parent_rate,
> + clk->pll_data->pll_table);
> +
> + if (!pll_cfg) {
> + dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
> + return -EINVAL;
> + }
> +
> + for (i = 0; pll_cfg[i].rate != 0; i++) {
> + if (pll_cfg[i].rate == rate) {
> + pll_write(clk, PLL_REG_IDIV,
> + encode_div(pll_cfg[i].idiv, 0));
> + pll_write(clk, PLL_REG_FBDIV,
> + encode_div(pll_cfg[i].fbdiv, 0));
> + pll_write(clk, PLL_REG_ODIV,
> + encode_div(pll_cfg[i].odiv, 1));
> +
> + /*
> + * Wait until CGU relocks.
> + * If after timeout CGU is unlocked yet return error
> + */
> + udelay(PLL_MAX_LOCK_TIME);
> + if (ioread32(clk->lock) & PLL_LOCK)
> + return 0;
> + else
> + return -ETIMEDOUT;
> + }
> + }
> +
> + dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
> + parent_rate);
> + return -EINVAL;
> +}
> +
> +static const struct clk_ops pll_ops = {
> + .recalc_rate = pll_recalc_rate,
> + .round_rate = pll_round_rate,
> + .set_rate = pll_set_rate,
> +};
> +
> +static int pll_clk_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + const char *parent_name;
> + struct clk *clk;
> + struct pll_clk *pll_clk;
> + struct resource *mem;
> + struct clk_init_data init = { };
> +
> + 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->base);
> +
> + init.name = dev->of_node->name;
> + init.ops = &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_data = of_device_get_match_data(dev);
> +
> + if (!pll_clk->pll_data) {
> + dev_err(dev, "No OF match data provided\n");
> + return -EINVAL;
> + }
> +
> + clk = devm_clk_register(dev, &pll_clk->hw);
> + if (IS_ERR(clk)) {
> + dev_err(dev, "failed to register %s clock (%ld)\n",
> + init.name, PTR_ERR(clk));
> + return PTR_ERR(clk);
> + }
> +
> + return of_clk_add_provider(dev->of_node, of_clk_src_simple_get, clk);
> +}
> +
> +static int pll_clk_remove(struct platform_device *pdev)
> +{
> + of_clk_del_provider(pdev->dev.of_node);
> + return 0;
> +}
> +
> +static void __init of_pll_clk_setup(struct device_node *node)
> +{
> + const char *parent_name;
> + struct clk *clk;
> + struct pll_clk *pll_clk;
> + struct clk_init_data init = { };
> +
> + 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");
> + iounmap(pll_clk->base);
> + return;
> + }
> +
> + pll_clk->lock = of_iomap(node, 1);
> + if (!pll_clk->lock) {
> + pr_err("failed to map pll lock register\n");
> + iounmap(pll_clk->lock);
> + return;
> + }
> +
> + init.name = node->name;
> + init.ops = &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_data = &arc_pll_data;
> +
> + clk = clk_register(NULL, &pll_clk->hw);
> + if (IS_ERR(clk)) {
> + pr_err("failed to register %s clock (%ld)\n",
> + node->name, PTR_ERR(clk));
> + kfree(pll_clk);
> + return;
> + }
> +
> + of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +}
> +
> +CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock", of_pll_clk_setup);
> +
> +static const struct of_device_id pll_clk_id[] = {
> + { .compatible = "snps,axs10x-arc-pll-clock", .data = &arc_pll_data},
> + { .compatible = "snps,axs10x-pgu-pll-clock", .data = &pgu_pll_data},
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, pll_clk_id);
> +
> +static struct platform_driver pll_clk_driver = {
> + .driver = {
> + .name = "axs10x-pll-clock",
> + .of_match_table = pll_clk_id,
> + },
> + .probe = pll_clk_probe,
> + .remove = pll_clk_remove,
> +};
> +builtin_platform_driver(pll_clk_driver);
> +
> +MODULE_AUTHOR("Vlad Zakharov <vzakhar at synopsys.com>");
> +MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
> +MODULE_LICENSE("GPL v2");
Maybe you have any comments or remarks about this patch? And if you don't could you please apply it.
Thanks!
--
Best regards,
Vlad Zakharov <vzakhar at synopsys.com>
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