diff options
author | Jose Abreu <Jose.Abreu@synopsys.com> | 2016-05-02 10:39:05 +0100 |
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committer | Stephen Boyd <sboyd@codeaurora.org> | 2016-05-06 10:35:04 -0700 |
commit | 923587aafc2c41ed516d39651d5750ea402cfc06 (patch) | |
tree | 533a48d7ef3592984d117786b7de2900a1abf554 | |
parent | c47265ad64fa793657ce7ecf1a8f636c794e9f40 (diff) | |
download | linux-923587aafc2c41ed516d39651d5750ea402cfc06.tar.bz2 |
clk/axs10x: Add I2S PLL clock driver
The ARC SDP I2S clock can be programmed using a
specific PLL.
This patch has the goal of adding a clock driver
that programs this PLL.
At this moment the rate values are hardcoded in
a table but in the future it would be ideal to
use a function which determines the PLL values
given the desired rate.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
-rw-r--r-- | Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt | 25 | ||||
-rw-r--r-- | drivers/clk/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/axs10x/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/axs10x/i2s_pll_clock.c | 228 |
4 files changed, 255 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt new file mode 100644 index 000000000000..5ffc8df7e6da --- /dev/null +++ b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt @@ -0,0 +1,25 @@ +Binding for the AXS10X I2S PLL clock + +This binding uses the common clock binding[1]. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +Required properties: +- compatible: shall be "snps,axs10x-i2s-pll-clock" +- reg : address and length of the I2S PLL register set. +- clocks: shall be the input parent clock phandle for the PLL. +- #clock-cells: from common clock binding; Should always be set to 0. + +Example: + pll_clock: pll_clock { + compatible = "fixed-clock"; + clock-frequency = <27000000>; + #clock-cells = <0>; + }; + + i2s_clock@100a0 { + compatible = "snps,axs10x-i2s-pll-clock"; + reg = <0x100a0 0x10>; + clocks = <&pll_clock>; + #clock-cells = <0>; + }; diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 4ef71a13ab37..6d1e3bef4e30 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -86,3 +86,4 @@ obj-$(CONFIG_X86) += x86/ obj-$(CONFIG_ARCH_ZX) += zte/ obj-$(CONFIG_ARCH_ZYNQ) += zynq/ obj-$(CONFIG_H8300) += h8300/ +obj-$(CONFIG_ARC_PLAT_AXS10X) += axs10x/ diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile new file mode 100644 index 000000000000..01996b871b06 --- /dev/null +++ b/drivers/clk/axs10x/Makefile @@ -0,0 +1 @@ +obj-y += i2s_pll_clock.o diff --git a/drivers/clk/axs10x/i2s_pll_clock.c b/drivers/clk/axs10x/i2s_pll_clock.c new file mode 100644 index 000000000000..411310d29581 --- /dev/null +++ b/drivers/clk/axs10x/i2s_pll_clock.c @@ -0,0 +1,228 @@ +/* + * Synopsys AXS10X SDP I2S PLL clock driver + * + * Copyright (C) 2016 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/err.h> +#include <linux/device.h> +#include <linux/of_address.h> +#include <linux/slab.h> +#include <linux/of.h> + +/* PLL registers addresses */ +#define PLL_IDIV_REG 0x0 +#define PLL_FBDIV_REG 0x4 +#define PLL_ODIV0_REG 0x8 +#define PLL_ODIV1_REG 0xC + +struct i2s_pll_cfg { + unsigned int rate; + unsigned int idiv; + unsigned int fbdiv; + unsigned int odiv0; + unsigned int odiv1; +}; + +static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = { + /* 27 Mhz */ + { 1024000, 0x104, 0x451, 0x10E38, 0x2000 }, + { 1411200, 0x104, 0x596, 0x10D35, 0x2000 }, + { 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 }, + { 2048000, 0x82, 0x451, 0x10E38, 0x2000 }, + { 2822400, 0x82, 0x596, 0x10D35, 0x2000 }, + { 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 }, + { 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 }, + { 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 }, + { 0, 0, 0, 0, 0 }, +}; + +static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = { + /* 28.224 Mhz */ + { 1024000, 0x82, 0x105, 0x107DF, 0x2000 }, + { 1411200, 0x28A, 0x1, 0x10001, 0x2000 }, + { 1536000, 0xA28, 0x187, 0x10042, 0x2000 }, + { 2048000, 0x41, 0x105, 0x107DF, 0x2000 }, + { 2822400, 0x145, 0x1, 0x10001, 0x2000 }, + { 3072000, 0x514, 0x187, 0x10042, 0x2000 }, + { 2116800, 0x514, 0x42, 0x10001, 0x2000 }, + { 2304000, 0x619, 0x82, 0x10001, 0x2000 }, + { 0, 0, 0, 0, 0 }, +}; + +struct i2s_pll_clk { + void __iomem *base; + struct clk_hw hw; + struct device *dev; +}; + +static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg, + unsigned int val) +{ + writel_relaxed(val, clk->base + reg); +} + +static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk, + unsigned int reg) +{ + return readl_relaxed(clk->base + reg); +} + +static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw) +{ + return container_of(hw, struct i2s_pll_clk, hw); +} + +static inline unsigned int i2s_pll_get_value(unsigned int val) +{ + return (val & 0x3F) + ((val >> 6) & 0x3F); +} + +static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate) +{ + switch (prate) { + case 27000000: + return i2s_pll_cfg_27m; + case 28224000: + return i2s_pll_cfg_28m; + default: + return NULL; + } +} + +static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct i2s_pll_clk *clk = to_i2s_pll_clk(hw); + unsigned int idiv, fbdiv, odiv; + + idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG)); + fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG)); + odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG)); + + return ((parent_rate / idiv) * fbdiv) / odiv; +} + +static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct i2s_pll_clk *clk = to_i2s_pll_clk(hw); + const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate); + int i; + + if (!pll_cfg) { + dev_err(clk->dev, "invalid parent rate=%ld\n", *prate); + return -EINVAL; + } + + for (i = 0; pll_cfg[i].rate != 0; i++) + if (pll_cfg[i].rate == rate) + return rate; + + return -EINVAL; +} + +static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct i2s_pll_clk *clk = to_i2s_pll_clk(hw); + const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate); + int i; + + 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) { + i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv); + i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv); + i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0); + i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1); + return 0; + } + } + + dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate, + parent_rate); + return -EINVAL; +} + +static const struct clk_ops i2s_pll_ops = { + .recalc_rate = i2s_pll_recalc_rate, + .round_rate = i2s_pll_round_rate, + .set_rate = i2s_pll_set_rate, +}; + +static int i2s_pll_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + const char *clk_name; + const char *parent_name; + struct clk *clk; + struct i2s_pll_clk *pll_clk; + struct clk_init_data init; + struct resource *mem; + + 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); + + clk_name = node->name; + init.name = clk_name; + init.ops = &i2s_pll_ops; + parent_name = of_clk_get_parent_name(node, 0); + init.parent_names = &parent_name; + init.num_parents = 1; + pll_clk->hw.init = &init; + pll_clk->dev = dev; + + clk = devm_clk_register(dev, &pll_clk->hw); + if (IS_ERR(clk)) { + dev_err(dev, "failed to register %s clock (%ld)\n", + clk_name, PTR_ERR(clk)); + return PTR_ERR(clk); + } + + return of_clk_add_provider(node, of_clk_src_simple_get, clk); +} + +static int i2s_pll_clk_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + return 0; +} + +static const struct of_device_id i2s_pll_clk_id[] = { + { .compatible = "snps,axs10x-i2s-pll-clock", }, + { }, +}; +MODULE_DEVICE_TABLE(of, i2s_pll_clk_id); + +static struct platform_driver i2s_pll_clk_driver = { + .driver = { + .name = "axs10x-i2s-pll-clock", + .of_match_table = i2s_pll_clk_id, + }, + .probe = i2s_pll_clk_probe, + .remove = i2s_pll_clk_remove, +}; +module_platform_driver(i2s_pll_clk_driver); + +MODULE_AUTHOR("Jose Abreu <joabreu@synopsys.com>"); +MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver"); +MODULE_LICENSE("GPL v2"); |