[PATCH 05/11] clk: Add Altera SoCFPGA clk support
Sascha Hauer
s.hauer at pengutronix.de
Mon Sep 16 04:48:14 EDT 2013
The SoCFPGA currently has all clocks described in the devicetree which
makes common clock support a straight forward task.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
drivers/clk/Kconfig | 5 +
drivers/clk/Makefile | 1 +
drivers/clk/socfpga.c | 412 ++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 418 insertions(+)
create mode 100644 drivers/clk/socfpga.c
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 2978c2e..1cf0ccb 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -12,3 +12,8 @@ config COMMON_CLK_OF_PROVIDER
bool
help
Clock driver provides OF-Tree based clock lookup.
+
+config CLK_SOCFPGA
+ bool
+ select COMMON_CLK_OF_PROVIDER
+ default y if ARCH_SOCFPGA && OFDEVICE
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a121947..f5c0592 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o
obj-$(CONFIG_ARCH_MVEBU) += mvebu/
obj-$(CONFIG_ARCH_MXS) += mxs/
obj-$(CONFIG_ARCH_TEGRA) += tegra/
+obj-$(CONFIG_CLK_SOCFPGA) += socfpga.o
diff --git a/drivers/clk/socfpga.c b/drivers/clk/socfpga.c
new file mode 100644
index 0000000..33a55cb
--- /dev/null
+++ b/drivers/clk/socfpga.c
@@ -0,0 +1,412 @@
+/*
+ * Copyright (C) 2013 Sascha Hauer <s.hauer at pengutronix.de>, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <driver.h>
+#include <linux/clk.h>
+#include <io.h>
+#include <malloc.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+
+/* Clock Manager offsets */
+#define CLKMGR_CTRL 0x0
+#define CLKMGR_BYPASS 0x4
+#define CLKMGR_L4SRC 0x70
+#define CLKMGR_PERPLL_SRC 0xAC
+
+/* Clock bypass bits */
+#define MAINPLL_BYPASS (1<<0)
+#define SDRAMPLL_BYPASS (1<<1)
+#define SDRAMPLL_SRC_BYPASS (1<<2)
+#define PERPLL_BYPASS (1<<3)
+#define PERPLL_SRC_BYPASS (1<<4)
+
+#define SOCFPGA_PLL_BG_PWRDWN 0
+#define SOCFPGA_PLL_EXT_ENA 1
+#define SOCFPGA_PLL_PWR_DOWN 2
+#define SOCFPGA_PLL_DIVF_MASK 0x0000FFF8
+#define SOCFPGA_PLL_DIVF_SHIFT 3
+#define SOCFPGA_PLL_DIVQ_MASK 0x003F0000
+#define SOCFPGA_PLL_DIVQ_SHIFT 16
+#define SOCFGPA_MAX_PARENTS 3
+
+#define SOCFPGA_DB_CLK "gpio_db_clk"
+
+#define div_mask(width) ((1 << (width)) - 1)
+#define streq(a, b) (strcmp((a), (b)) == 0)
+
+static void __iomem *clk_mgr_base_addr;
+
+char *of_clk_get_parent_name(struct device_node *np, unsigned int index)
+{
+ struct of_phandle_args clkspec;
+ const char *clk_name;
+ int rc;
+
+ rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
+ &clkspec);
+ if (rc)
+ return NULL;
+
+ if (of_property_read_string_index(clkspec.np, "clock-output-names",
+ clkspec.args_count ? clkspec.args[0] : 0,
+ &clk_name) < 0)
+ clk_name = clkspec.np->name;
+
+ return xstrdup(clk_name);
+}
+
+static struct clk *socfpga_fixed_clk(struct device_node *node)
+{
+ uint32_t f = 0;
+
+ of_property_read_u32(node, "clock-frequency", &f);
+
+ return clk_fixed(node->name, f);
+}
+
+struct clk_pll {
+ struct clk clk;
+ const char *parent;
+ unsigned regofs;
+};
+
+static unsigned long clk_pll_recalc_rate(struct clk *clk,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = container_of(clk, struct clk_pll, clk);
+ unsigned long divf, divq, vco_freq, reg;
+ unsigned long bypass;
+
+ reg = readl(clk_mgr_base_addr + pll->regofs);
+
+ bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
+ if (bypass & MAINPLL_BYPASS)
+ return parent_rate;
+
+ divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
+ divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
+ vco_freq = parent_rate * (divf + 1);
+
+ return vco_freq / (1 + divq);
+}
+
+static struct clk_ops clk_pll_ops = {
+ .recalc_rate = clk_pll_recalc_rate,
+};
+
+static struct clk *socfpga_pll_clk(struct device_node *node)
+{
+ struct clk_pll *pll;
+ int ret;
+
+ pll = xzalloc(sizeof(*pll));
+
+ pll->parent = of_clk_get_parent_name(node, 0);
+ if (!pll->parent)
+ return ERR_PTR(-EINVAL);
+
+ pll->clk.parent_names = &pll->parent;
+ pll->clk.num_parents = 1;
+ pll->clk.name = xstrdup(node->name);
+ pll->clk.ops = &clk_pll_ops;
+
+ of_property_read_u32(node, "reg", &pll->regofs);
+
+ ret = clk_register(&pll->clk);
+ if (ret) {
+ free(pll);
+ return ERR_PTR(ret);
+ }
+
+ return &pll->clk;
+}
+
+struct clk_periph {
+ struct clk clk;
+ const char *parent;
+ unsigned regofs;
+ unsigned int fixed_div;
+};
+
+static unsigned long clk_periph_recalc_rate(struct clk *clk,
+ unsigned long parent_rate)
+{
+ struct clk_periph *periph = container_of(clk, struct clk_periph, clk);
+ u32 div;
+
+ if (periph->fixed_div)
+ div = periph->fixed_div;
+ else
+ div = ((readl(clk_mgr_base_addr + periph->regofs) & 0x1ff) + 1);
+
+ return parent_rate / div;
+}
+
+static struct clk_ops clk_periph_ops = {
+ .recalc_rate = clk_periph_recalc_rate,
+};
+
+static struct clk *socfpga_periph_clk(struct device_node *node)
+{
+ struct clk_periph *periph;
+ int ret;
+
+ periph = xzalloc(sizeof(*periph));
+
+ periph->parent = of_clk_get_parent_name(node, 0);
+ if (!periph->parent)
+ return ERR_PTR(-EINVAL);
+
+ periph->clk.parent_names = &periph->parent;
+ periph->clk.num_parents = 1;
+ periph->clk.name = xstrdup(node->name);
+ periph->clk.ops = &clk_periph_ops;
+
+ of_property_read_u32(node, "reg", &periph->regofs);
+ of_property_read_u32(node, "fixed-divider", &periph->fixed_div);
+
+ ret = clk_register(&periph->clk);
+ if (ret) {
+ free(periph);
+ return ERR_PTR(ret);
+ }
+
+ return &periph->clk;
+}
+
+struct clk_socfpga {
+ struct clk clk;
+ const char *parent;
+ void __iomem *reg;
+ void __iomem *div_reg;
+ void __iomem *parent_reg;
+ unsigned int fixed_div;
+ unsigned int bit_idx;
+ unsigned int shift;
+ unsigned int width;
+ unsigned int parent_shift;
+ unsigned int parent_width;
+ const char *parent_names[SOCFGPA_MAX_PARENTS];
+};
+
+static int clk_socfpga_enable(struct clk *clk)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+ u32 val;
+
+ val = readl(cs->reg);
+ val |= 1 << cs->shift;
+ writel(val, cs->reg);
+
+ return 0;
+}
+
+static void clk_socfpga_disable(struct clk *clk)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+ u32 val;
+
+ val = readl(cs->reg);
+ val &= ~(1 << cs->shift);
+ writel(val, cs->reg);
+}
+
+static int clk_socfpga_is_enabled(struct clk *clk)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+ u32 val;
+
+ val = readl(cs->reg);
+
+ if (val & (1 << cs->shift))
+ return 1;
+ else
+ return 0;
+}
+
+static unsigned long clk_socfpga_recalc_rate(struct clk *clk,
+ unsigned long parent_rate)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+ u32 div = 1, val;
+
+ if (cs->fixed_div) {
+ div = cs->fixed_div;
+ } else if (cs->div_reg) {
+ val = readl(cs->div_reg) >> cs->shift;
+ val &= div_mask(cs->width);
+ if (streq(clk->name, SOCFPGA_DB_CLK))
+ div = val + 1;
+ else
+ div = (1 << val);
+ }
+
+ return parent_rate / div;
+}
+
+static int clk_socfpga_get_parent(struct clk *clk)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+
+ return readl(cs->parent_reg) >> cs->parent_shift &
+ ((1 << cs->parent_width) - 1);
+}
+
+static int clk_socfpga_set_parent(struct clk *clk, u8 parent)
+{
+ struct clk_socfpga *cs = container_of(clk, struct clk_socfpga, clk);
+ uint32_t val;
+
+ val = readl(cs->parent_reg);
+ val &= ~(((1 << cs->parent_width) - 1) << cs->parent_shift);
+ val |= parent << cs->parent_shift;
+ writel(val, cs->parent_reg);
+
+ return 0;
+}
+
+static struct clk_ops clk_socfpga_ops = {
+ .recalc_rate = clk_socfpga_recalc_rate,
+ .enable = clk_socfpga_enable,
+ .disable = clk_socfpga_disable,
+ .is_enabled = clk_socfpga_is_enabled,
+ .get_parent = clk_socfpga_get_parent,
+ .set_parent = clk_socfpga_set_parent,
+};
+
+static struct clk *socfpga_gate_clk(struct device_node *node)
+{
+ u32 clk_gate[2];
+ u32 div_reg[3];
+ u32 parent_reg[3];
+ u32 fixed_div;
+ struct clk_socfpga *cs;
+ int ret;
+ int i = 0;
+
+ cs = xzalloc(sizeof(*cs));
+
+ ret = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
+ if (ret)
+ clk_gate[0] = 0;
+
+ if (clk_gate[0]) {
+ cs->reg = clk_mgr_base_addr + clk_gate[0];
+ cs->bit_idx = clk_gate[1];
+ }
+
+ ret = of_property_read_u32(node, "fixed-divider", &fixed_div);
+ if (ret)
+ cs->fixed_div = 0;
+ else
+ cs->fixed_div = fixed_div;
+
+ ret = of_property_read_u32_array(node, "div-reg", div_reg, 3);
+ if (!ret) {
+ cs->div_reg = clk_mgr_base_addr + div_reg[0];
+ cs->shift = div_reg[1];
+ cs->width = div_reg[2];
+ }
+
+ ret = of_property_read_u32_array(node, "parent-reg", parent_reg, 3);
+ if (!ret) {
+ cs->parent_reg = clk_mgr_base_addr + parent_reg[0];
+ cs->parent_shift = parent_reg[1];
+ cs->parent_width = parent_reg[2];
+ }
+
+ for (i = 0; i < SOCFGPA_MAX_PARENTS; i++) {
+ cs->parent_names[i] = of_clk_get_parent_name(node, i);
+ if (!cs->parent_names[i])
+ break;
+ }
+
+ cs->clk.parent_names = cs->parent_names;
+ cs->clk.num_parents = i;
+ cs->clk.name = xstrdup(node->name);
+ cs->clk.ops = &clk_socfpga_ops;
+
+ ret = clk_register(&cs->clk);
+ if (ret) {
+ free(cs);
+ return ERR_PTR(ret);
+ }
+
+ return &cs->clk;
+}
+
+static void socfpga_register_clocks(struct device_d *dev, struct device_node *node)
+{
+ struct device_node *child;
+ struct clk *clk;
+
+ for_each_child_of_node(node, child) {
+ socfpga_register_clocks(dev, child);
+ }
+
+ if (of_device_is_compatible(node, "fixed-clock"))
+ clk = socfpga_fixed_clk(node);
+ else if (of_device_is_compatible(node, "altr,socfpga-pll-clock"))
+ clk = socfpga_pll_clk(node);
+ else if (of_device_is_compatible(node, "altr,socfpga-perip-clk"))
+ clk = socfpga_periph_clk(node);
+ else if (of_device_is_compatible(node, "altr,socfpga-gate-clk"))
+ clk = socfpga_gate_clk(node);
+ else
+ return;
+
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+
+static int socfpga_ccm_probe(struct device_d *dev)
+{
+ void __iomem *regs;
+ struct device_node *clknode;
+
+ regs = dev_request_mem_region(dev, 0);
+ if (!regs)
+ return -EBUSY;
+
+ clk_mgr_base_addr = regs;
+
+ clknode = of_get_child_by_name(dev->device_node, "clocks");
+ if (!clknode)
+ return -EINVAL;
+
+ socfpga_register_clocks(dev, clknode);
+
+ return 0;
+}
+
+static __maybe_unused struct of_device_id socfpga_ccm_dt_ids[] = {
+ {
+ .compatible = "altr,clk-mgr",
+ }, {
+ /* sentinel */
+ }
+};
+
+static struct driver_d socfpga_ccm_driver = {
+ .probe = socfpga_ccm_probe,
+ .name = "socfpga-ccm",
+ .of_compatible = DRV_OF_COMPAT(socfpga_ccm_dt_ids),
+};
+
+static int socfpga_ccm_init(void)
+{
+ return platform_driver_register(&socfpga_ccm_driver);
+}
+core_initcall(socfpga_ccm_init);
--
1.8.4.rc3
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