diff options
| -rw-r--r-- | Documentation/devicetree/bindings/clock/zynq-7000.txt | 55 | ||||
| -rw-r--r-- | drivers/clk/clk-zynq.c | 383 | ||||
| -rw-r--r-- | include/linux/clk/zynq.h | 24 |
3 files changed, 462 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/zynq-7000.txt b/Documentation/devicetree/bindings/clock/zynq-7000.txt new file mode 100644 index 00000000000..23ae1db1bc1 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/zynq-7000.txt @@ -0,0 +1,55 @@ +Device Tree Clock bindings for the Zynq 7000 EPP + +The Zynq EPP has several different clk providers, each with there own bindings. +The purpose of this document is to document their usage. + +See clock_bindings.txt for more information on the generic clock bindings. +See Chapter 25 of Zynq TRM for more information about Zynq clocks. + +== PLLs == + +Used to describe the ARM_PLL, DDR_PLL, and IO_PLL. + +Required properties: +- #clock-cells : shall be 0 (only one clock is output from this node) +- compatible : "xlnx,zynq-pll" +- reg : pair of u32 values, which are the address offsets within the SLCR + of the relevant PLL_CTRL register and PLL_CFG register respectively +- clocks : phandle for parent clock. should be the phandle for ps_clk + +Optional properties: +- clock-output-names : name of the output clock + +Example: + armpll: armpll { + #clock-cells = <0>; + compatible = "xlnx,zynq-pll"; + clocks = <&ps_clk>; + reg = <0x100 0x110>; + clock-output-names = "armpll"; + }; + +== Peripheral clocks == + +Describes clock node for the SDIO, SMC, SPI, QSPI, and UART clocks. + +Required properties: +- #clock-cells : shall be 1 +- compatible : "xlnx,zynq-periph-clock" +- reg : a single u32 value, describing the offset within the SLCR where + the CLK_CTRL register is found for this peripheral +- clocks : phandle for parent clocks. should hold phandles for + the IO_PLL, ARM_PLL, and DDR_PLL in order +- clock-output-names : names of the output clock(s). For peripherals that have + two output clocks (for example, the UART), two clocks + should be listed. + +Example: + uart_clk: uart_clk { + #clock-cells = <1>; + compatible = "xlnx,zynq-periph-clock"; + clocks = <&iopll &armpll &ddrpll>; + reg = <0x154>; + clock-output-names = "uart0_ref_clk", + "uart1_ref_clk"; + }; diff --git a/drivers/clk/clk-zynq.c b/drivers/clk/clk-zynq.c new file mode 100644 index 00000000000..37a30514fd6 --- /dev/null +++ b/drivers/clk/clk-zynq.c @@ -0,0 +1,383 @@ +/* + * Copyright (c) 2012 National Instruments + * + * Josh Cartwright <josh.cartwright@ni.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/io.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/clk-provider.h> + +static void __iomem *slcr_base; + +struct zynq_pll_clk { + struct clk_hw hw; + void __iomem *pll_ctrl; + void __iomem *pll_cfg; +}; + +#define to_zynq_pll_clk(hw) container_of(hw, struct zynq_pll_clk, hw) + +#define CTRL_PLL_FDIV(x) ((x) >> 12) + +static unsigned long zynq_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct zynq_pll_clk *pll = to_zynq_pll_clk(hw); + return parent_rate * CTRL_PLL_FDIV(ioread32(pll->pll_ctrl)); +} + +static const struct clk_ops zynq_pll_clk_ops = { + .recalc_rate = zynq_pll_recalc_rate, +}; + +static void __init zynq_pll_clk_setup(struct device_node *np) +{ + struct clk_init_data init; + struct zynq_pll_clk *pll; + const char *parent_name; + struct clk *clk; + u32 regs[2]; + int ret; + + ret = of_property_read_u32_array(np, "reg", regs, ARRAY_SIZE(regs)); + if (WARN_ON(ret)) + return; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (WARN_ON(!pll)) + return; + + pll->pll_ctrl = slcr_base + regs[0]; + pll->pll_cfg = slcr_base + regs[1]; + + of_property_read_string(np, "clock-output-names", &init.name); + + init.ops = &zynq_pll_clk_ops; + parent_name = of_clk_get_parent_name(np, 0); + init.parent_names = &parent_name; + init.num_parents = 1; + + pll->hw.init = &init; + + clk = clk_register(NULL, &pll->hw); + if (WARN_ON(IS_ERR(clk))) + return; + + ret = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (WARN_ON(ret)) + return; +} + +struct zynq_periph_clk { + struct clk_hw hw; + struct clk_onecell_data onecell_data; + struct clk *gates[2]; + void __iomem *clk_ctrl; + spinlock_t clkact_lock; +}; + +#define to_zynq_periph_clk(hw) container_of(hw, struct zynq_periph_clk, hw) + +static const u8 periph_clk_parent_map[] = { + 0, 0, 1, 2 +}; +#define PERIPH_CLK_CTRL_SRC(x) (periph_clk_parent_map[((x) & 0x30) >> 4]) +#define PERIPH_CLK_CTRL_DIV(x) (((x) & 0x3F00) >> 8) + +static unsigned long zynq_periph_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct zynq_periph_clk *periph = to_zynq_periph_clk(hw); + return parent_rate / PERIPH_CLK_CTRL_DIV(ioread32(periph->clk_ctrl)); +} + +static u8 zynq_periph_get_parent(struct clk_hw *hw) +{ + struct zynq_periph_clk *periph = to_zynq_periph_clk(hw); + return PERIPH_CLK_CTRL_SRC(ioread32(periph->clk_ctrl)); +} + +static const struct clk_ops zynq_periph_clk_ops = { + .recalc_rate = zynq_periph_recalc_rate, + .get_parent = zynq_periph_get_parent, +}; + +static void __init zynq_periph_clk_setup(struct device_node *np) +{ + struct zynq_periph_clk *periph; + const char *parent_names[3]; + struct clk_init_data init; + int clk_num = 0, err; + const char *name; + struct clk *clk; + u32 reg; + int i; + + err = of_property_read_u32(np, "reg", ®); + if (WARN_ON(err)) + return; + + periph = kzalloc(sizeof(*periph), GFP_KERNEL); + if (WARN_ON(!periph)) + return; + + periph->clk_ctrl = slcr_base + reg; + spin_lock_init(&periph->clkact_lock); + + init.name = np->name; + init.ops = &zynq_periph_clk_ops; + for (i = 0; i < ARRAY_SIZE(parent_names); i++) + parent_names[i] = of_clk_get_parent_name(np, i); + init.parent_names = parent_names; + init.num_parents = ARRAY_SIZE(parent_names); + + periph->hw.init = &init; + + clk = clk_register(NULL, &periph->hw); + if (WARN_ON(IS_ERR(clk))) + return; + + err = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (WARN_ON(err)) + return; + + err = of_property_read_string_index(np, "clock-output-names", 0, + &name); + if (WARN_ON(err)) + return; + + periph->gates[0] = clk_register_gate(NULL, name, np->name, 0, + periph->clk_ctrl, 0, 0, + &periph->clkact_lock); + if (WARN_ON(IS_ERR(periph->gates[0]))) + return; + clk_num++; + + /* some periph clks have 2 downstream gates */ + err = of_property_read_string_index(np, "clock-output-names", 1, + &name); + if (err != -ENODATA) { + periph->gates[1] = clk_register_gate(NULL, name, np->name, 0, + periph->clk_ctrl, 1, 0, + &periph->clkact_lock); + if (WARN_ON(IS_ERR(periph->gates[1]))) + return; + clk_num++; + } + + periph->onecell_data.clks = periph->gates; + periph->onecell_data.clk_num = clk_num; + + err = of_clk_add_provider(np, of_clk_src_onecell_get, + &periph->onecell_data); + if (WARN_ON(err)) + return; +} + +/* CPU Clock domain is modelled as a mux with 4 children subclks, whose + * derivative rates depend on CLK_621_TRUE + */ + +struct zynq_cpu_clk { + struct clk_hw hw; + struct clk_onecell_data onecell_data; + struct clk *subclks[4]; + void __iomem *clk_ctrl; + spinlock_t clkact_lock; +}; + +#define to_zynq_cpu_clk(hw) container_of(hw, struct zynq_cpu_clk, hw) + +static const u8 zynq_cpu_clk_parent_map[] = { + 1, 1, 2, 0 +}; +#define CPU_CLK_SRCSEL(x) (zynq_cpu_clk_parent_map[(((x) & 0x30) >> 4)]) +#define CPU_CLK_CTRL_DIV(x) (((x) & 0x3F00) >> 8) + +static u8 zynq_cpu_clk_get_parent(struct clk_hw *hw) +{ + struct zynq_cpu_clk *cpuclk = to_zynq_cpu_clk(hw); + return CPU_CLK_SRCSEL(ioread32(cpuclk->clk_ctrl)); +} + +static unsigned long zynq_cpu_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct zynq_cpu_clk *cpuclk = to_zynq_cpu_clk(hw); + return parent_rate / CPU_CLK_CTRL_DIV(ioread32(cpuclk->clk_ctrl)); +} + +static const struct clk_ops zynq_cpu_clk_ops = { + .get_parent = zynq_cpu_clk_get_parent, + .recalc_rate = zynq_cpu_clk_recalc_rate, +}; + +struct zynq_cpu_subclk { + struct clk_hw hw; + void __iomem *clk_621; + enum { + CPU_SUBCLK_6X4X, + CPU_SUBCLK_3X2X, + CPU_SUBCLK_2X, + CPU_SUBCLK_1X, + } which; +}; + +#define CLK_621_TRUE(x) ((x) & 1) + +#define to_zynq_cpu_subclk(hw) container_of(hw, struct zynq_cpu_subclk, hw); + +static unsigned long zynq_cpu_subclk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + unsigned long uninitialized_var(rate); + struct zynq_cpu_subclk *subclk; + bool is_621; + + subclk = to_zynq_cpu_subclk(hw) + is_621 = CLK_621_TRUE(ioread32(subclk->clk_621)); + + switch (subclk->which) { + case CPU_SUBCLK_6X4X: + rate = parent_rate; + break; + case CPU_SUBCLK_3X2X: + rate = parent_rate / 2; + break; + case CPU_SUBCLK_2X: + rate = parent_rate / (is_621 ? 3 : 2); + break; + case CPU_SUBCLK_1X: + rate = parent_rate / (is_621 ? 6 : 4); + break; + }; + + return rate; +} + +static const struct clk_ops zynq_cpu_subclk_ops = { + .recalc_rate = zynq_cpu_subclk_recalc_rate, +}; + +static struct clk *zynq_cpu_subclk_setup(struct device_node *np, u8 which, + void __iomem *clk_621) +{ + struct zynq_cpu_subclk *subclk; + struct clk_init_data init; + struct clk *clk; + int err; + + err = of_property_read_string_index(np, "clock-output-names", + which, &init.name); + if (WARN_ON(err)) + goto err_read_output_name; + + subclk = kzalloc(sizeof(*subclk), GFP_KERNEL); + if (!subclk) + goto err_subclk_alloc; + + subclk->clk_621 = clk_621; + subclk->which = which; + + init.ops = &zynq_cpu_subclk_ops; + init.parent_names = &np->name; + init.num_parents = 1; + + subclk->hw.init = &init; + + clk = clk_register(NULL, &subclk->hw); + if (WARN_ON(IS_ERR(clk))) + goto err_clk_register; + + return clk; + +err_clk_register: + kfree(subclk); +err_subclk_alloc: +err_read_output_name: + return ERR_PTR(-EINVAL); +} + +static void __init zynq_cpu_clk_setup(struct device_node *np) +{ + struct zynq_cpu_clk *cpuclk; + const char *parent_names[3]; + struct clk_init_data init; + void __iomem *clk_621; + struct clk *clk; + u32 reg[2]; + int err; + int i; + + err = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg)); + if (WARN_ON(err)) + return; + + cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL); + if (WARN_ON(!cpuclk)) + return; + + cpuclk->clk_ctrl = slcr_base + reg[0]; + clk_621 = slcr_base + reg[1]; + spin_lock_init(&cpuclk->clkact_lock); + + init.name = np->name; + init.ops = &zynq_cpu_clk_ops; + for (i = 0; i < ARRAY_SIZE(parent_names); i++) + parent_names[i] = of_clk_get_parent_name(np, i); + init.parent_names = parent_names; + init.num_parents = ARRAY_SIZE(parent_names); + + cpuclk->hw.init = &init; + + clk = clk_register(NULL, &cpuclk->hw); + if (WARN_ON(IS_ERR(clk))) + return; + + err = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (WARN_ON(err)) + return; + + for (i = 0; i < 4; i++) { + cpuclk->subclks[i] = zynq_cpu_subclk_setup(np, i, clk_621); + if (WARN_ON(IS_ERR(cpuclk->subclks[i]))) + return; + } + + cpuclk->onecell_data.clks = cpuclk->subclks; + cpuclk->onecell_data.clk_num = i; + + err = of_clk_add_provider(np, of_clk_src_onecell_get, + &cpuclk->onecell_data); + if (WARN_ON(err)) + return; +} + +static const __initconst struct of_device_id zynq_clk_match[] = { + { .compatible = "fixed-clock", .data = of_fixed_clk_setup, }, + { .compatible = "xlnx,zynq-pll", .data = zynq_pll_clk_setup, }, + { .compatible = "xlnx,zynq-periph-clock", + .data = zynq_periph_clk_setup, }, + { .compatible = "xlnx,zynq-cpu-clock", .data = zynq_cpu_clk_setup, }, + {} +}; + +void __init xilinx_zynq_clocks_init(void __iomem *slcr) +{ + slcr_base = slcr; + of_clk_init(zynq_clk_match); +} diff --git a/include/linux/clk/zynq.h b/include/linux/clk/zynq.h new file mode 100644 index 00000000000..56be7cd9aa8 --- /dev/null +++ b/include/linux/clk/zynq.h @@ -0,0 +1,24 @@ +/* + * Copyright (C) 2012 National Instruments + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef __LINUX_CLK_ZYNQ_H_ +#define __LINUX_CLK_ZYNQ_H_ + +void __init xilinx_zynq_clocks_init(void __iomem *slcr); + +#endif |