clk: Add Gemini SoC clock controller
The Cortina Systems Gemini (SL3516/CS3516) has an on-chip clock
controller that derive all clocks from a single crystal, using some
documented and some undocumented PLLs, half dividers, counters and
gates. This is a best attempt to construct a clock driver for the
clocks so at least we can gate off unused hardware and driver the
PCI bus clock.
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[sboyd@codeaurora.org: Fix devm_ioremap_resource() return value
checking]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 10fef77..d406b08 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -126,6 +126,15 @@
help
If you say yes here you get support for the CS2000 clock multiplier.
+config COMMON_CLK_GEMINI
+ bool "Clock driver for Cortina Systems Gemini SoC"
+ depends on ARCH_GEMINI || COMPILE_TEST
+ select MFD_SYSCON
+ select RESET_CONTROLLER
+ ---help---
+ This driver supports the SoC clocks on the Cortina Systems Gemini
+ platform, also known as SL3516 or CS3516.
+
config COMMON_CLK_S2MPS11
tristate "Clock driver for S2MPS1X/S5M8767 MFD"
depends on MFD_SEC_CORE || COMPILE_TEST
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index de99e60..4f6a812 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -25,6 +25,7 @@
obj-$(CONFIG_ARCH_CLPS711X) += clk-clps711x.o
obj-$(CONFIG_COMMON_CLK_CS2000_CP) += clk-cs2000-cp.o
obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
+obj-$(CONFIG_COMMON_CLK_GEMINI) += clk-gemini.o
obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
obj-$(CONFIG_ARCH_MB86S7X) += clk-mb86s7x.o
diff --git a/drivers/clk/clk-gemini.c b/drivers/clk/clk-gemini.c
new file mode 100644
index 0000000..b82db96
--- /dev/null
+++ b/drivers/clk/clk-gemini.c
@@ -0,0 +1,454 @@
+/*
+ * Cortina Gemini SoC Clock Controller driver
+ * Copyright (c) 2017 Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#define pr_fmt(fmt) "clk-gemini: " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/reset-controller.h>
+#include <dt-bindings/reset/cortina,gemini-reset.h>
+#include <dt-bindings/clock/cortina,gemini-clock.h>
+
+/* Globally visible clocks */
+static DEFINE_SPINLOCK(gemini_clk_lock);
+
+#define GEMINI_GLOBAL_STATUS 0x04
+#define PLL_OSC_SEL BIT(30)
+#define AHBSPEED_SHIFT (15)
+#define AHBSPEED_MASK 0x07
+#define CPU_AHB_RATIO_SHIFT (18)
+#define CPU_AHB_RATIO_MASK 0x03
+
+#define GEMINI_GLOBAL_PLL_CONTROL 0x08
+
+#define GEMINI_GLOBAL_SOFT_RESET 0x0c
+
+#define GEMINI_GLOBAL_MISC_CONTROL 0x30
+#define PCI_CLK_66MHZ BIT(18)
+#define PCI_CLK_OE BIT(17)
+
+#define GEMINI_GLOBAL_CLOCK_CONTROL 0x34
+#define PCI_CLKRUN_EN BIT(16)
+#define TVC_HALFDIV_SHIFT (24)
+#define TVC_HALFDIV_MASK 0x1f
+#define SECURITY_CLK_SEL BIT(29)
+
+#define GEMINI_GLOBAL_PCI_DLL_CONTROL 0x44
+#define PCI_DLL_BYPASS BIT(31)
+#define PCI_DLL_TAP_SEL_MASK 0x1f
+
+/**
+ * struct gemini_data_data - Gemini gated clocks
+ * @bit_idx: the bit used to gate this clock in the clock register
+ * @name: the clock name
+ * @parent_name: the name of the parent clock
+ * @flags: standard clock framework flags
+ */
+struct gemini_gate_data {
+ u8 bit_idx;
+ const char *name;
+ const char *parent_name;
+ unsigned long flags;
+};
+
+/**
+ * struct clk_gemini_pci - Gemini PCI clock
+ * @hw: corresponding clock hardware entry
+ * @map: regmap to access the registers
+ * @rate: current rate
+ */
+struct clk_gemini_pci {
+ struct clk_hw hw;
+ struct regmap *map;
+ unsigned long rate;
+};
+
+/**
+ * struct gemini_reset - gemini reset controller
+ * @map: regmap to access the containing system controller
+ * @rcdev: reset controller device
+ */
+struct gemini_reset {
+ struct regmap *map;
+ struct reset_controller_dev rcdev;
+};
+
+/* Keeps track of all clocks */
+static struct clk_hw_onecell_data *gemini_clk_data;
+
+static const struct gemini_gate_data gemini_gates[] = {
+ { 1, "security-gate", "secdiv", 0 },
+ { 2, "gmac0-gate", "ahb", 0 },
+ { 3, "gmac1-gate", "ahb", 0 },
+ { 4, "sata0-gate", "ahb", 0 },
+ { 5, "sata1-gate", "ahb", 0 },
+ { 6, "usb0-gate", "ahb", 0 },
+ { 7, "usb1-gate", "ahb", 0 },
+ { 8, "ide-gate", "ahb", 0 },
+ { 9, "pci-gate", "ahb", 0 },
+ /*
+ * The DDR controller may never have a driver, but certainly must
+ * not be gated off.
+ */
+ { 10, "ddr-gate", "ahb", CLK_IS_CRITICAL },
+ /*
+ * The flash controller must be on to access NOR flash through the
+ * memory map.
+ */
+ { 11, "flash-gate", "ahb", CLK_IGNORE_UNUSED },
+ { 12, "tvc-gate", "ahb", 0 },
+ { 13, "boot-gate", "apb", 0 },
+};
+
+#define to_pciclk(_hw) container_of(_hw, struct clk_gemini_pci, hw)
+
+#define to_gemini_reset(p) container_of((p), struct gemini_reset, rcdev)
+
+static unsigned long gemini_pci_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_gemini_pci *pciclk = to_pciclk(hw);
+ u32 val;
+
+ regmap_read(pciclk->map, GEMINI_GLOBAL_MISC_CONTROL, &val);
+ if (val & PCI_CLK_66MHZ)
+ return 66000000;
+ return 33000000;
+}
+
+static long gemini_pci_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ /* We support 33 and 66 MHz */
+ if (rate < 48000000)
+ return 33000000;
+ return 66000000;
+}
+
+static int gemini_pci_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_gemini_pci *pciclk = to_pciclk(hw);
+
+ if (rate == 33000000)
+ return regmap_update_bits(pciclk->map,
+ GEMINI_GLOBAL_MISC_CONTROL,
+ PCI_CLK_66MHZ, 0);
+ if (rate == 66000000)
+ return regmap_update_bits(pciclk->map,
+ GEMINI_GLOBAL_MISC_CONTROL,
+ 0, PCI_CLK_66MHZ);
+ return -EINVAL;
+}
+
+static int gemini_pci_enable(struct clk_hw *hw)
+{
+ struct clk_gemini_pci *pciclk = to_pciclk(hw);
+
+ regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
+ 0, PCI_CLKRUN_EN);
+ regmap_update_bits(pciclk->map,
+ GEMINI_GLOBAL_MISC_CONTROL,
+ 0, PCI_CLK_OE);
+ return 0;
+}
+
+static void gemini_pci_disable(struct clk_hw *hw)
+{
+ struct clk_gemini_pci *pciclk = to_pciclk(hw);
+
+ regmap_update_bits(pciclk->map,
+ GEMINI_GLOBAL_MISC_CONTROL,
+ PCI_CLK_OE, 0);
+ regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
+ PCI_CLKRUN_EN, 0);
+}
+
+static int gemini_pci_is_enabled(struct clk_hw *hw)
+{
+ struct clk_gemini_pci *pciclk = to_pciclk(hw);
+ unsigned int val;
+
+ regmap_read(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
+ return !!(val & PCI_CLKRUN_EN);
+}
+
+static const struct clk_ops gemini_pci_clk_ops = {
+ .recalc_rate = gemini_pci_recalc_rate,
+ .round_rate = gemini_pci_round_rate,
+ .set_rate = gemini_pci_set_rate,
+ .enable = gemini_pci_enable,
+ .disable = gemini_pci_disable,
+ .is_enabled = gemini_pci_is_enabled,
+};
+
+static struct clk_hw *gemini_pci_clk_setup(const char *name,
+ const char *parent_name,
+ struct regmap *map)
+{
+ struct clk_gemini_pci *pciclk;
+ struct clk_init_data init;
+ int ret;
+
+ pciclk = kzalloc(sizeof(*pciclk), GFP_KERNEL);
+ if (!pciclk)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &gemini_pci_clk_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+ pciclk->map = map;
+ pciclk->hw.init = &init;
+
+ ret = clk_hw_register(NULL, &pciclk->hw);
+ if (ret) {
+ kfree(pciclk);
+ return ERR_PTR(ret);
+ }
+
+ return &pciclk->hw;
+}
+
+/*
+ * This is a self-deasserting reset controller.
+ */
+static int gemini_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct gemini_reset *gr = to_gemini_reset(rcdev);
+
+ /* Manual says to always set BIT 30 (CPU1) to 1 */
+ return regmap_write(gr->map,
+ GEMINI_GLOBAL_SOFT_RESET,
+ BIT(GEMINI_RESET_CPU1) | BIT(id));
+}
+
+static int gemini_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct gemini_reset *gr = to_gemini_reset(rcdev);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & BIT(id));
+}
+
+static const struct reset_control_ops gemini_reset_ops = {
+ .reset = gemini_reset,
+ .status = gemini_reset_status,
+};
+
+static int gemini_clk_probe(struct platform_device *pdev)
+{
+ /* Gives the fracions 1x, 1.5x, 1.85x and 2x */
+ unsigned int cpu_ahb_mult[4] = { 1, 3, 24, 2 };
+ unsigned int cpu_ahb_div[4] = { 1, 2, 13, 1 };
+ void __iomem *base;
+ struct gemini_reset *gr;
+ struct regmap *map;
+ struct clk_hw *hw;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ unsigned int mult, div;
+ struct resource *res;
+ u32 val;
+ int ret;
+ int i;
+
+ gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL);
+ if (!gr)
+ return -ENOMEM;
+
+ /* Remap the system controller for the exclusive register */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ map = syscon_node_to_regmap(np);
+ if (IS_ERR(map)) {
+ dev_err(dev, "no syscon regmap\n");
+ return PTR_ERR(map);
+ }
+
+ gr->map = map;
+ gr->rcdev.owner = THIS_MODULE;
+ gr->rcdev.nr_resets = 32;
+ gr->rcdev.ops = &gemini_reset_ops;
+ gr->rcdev.of_node = np;
+
+ ret = devm_reset_controller_register(dev, &gr->rcdev);
+ if (ret) {
+ dev_err(dev, "could not register reset controller\n");
+ return ret;
+ }
+
+ /* RTC clock 32768 Hz */
+ hw = clk_hw_register_fixed_rate(NULL, "rtc", NULL, 0, 32768);
+ gemini_clk_data->hws[GEMINI_CLK_RTC] = hw;
+
+ /* CPU clock derived as a fixed ratio from the AHB clock */
+ val >>= CPU_AHB_RATIO_SHIFT;
+ val &= CPU_AHB_RATIO_MASK;
+ hw = clk_hw_register_fixed_factor(NULL, "cpu", "ahb", 0,
+ cpu_ahb_mult[val],
+ cpu_ahb_div[val]);
+ gemini_clk_data->hws[GEMINI_CLK_CPU] = hw;
+
+ /* Security clock is 1:1 or 0.75 of APB */
+ regmap_read(map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
+ if (val & SECURITY_CLK_SEL) {
+ mult = 1;
+ div = 1;
+ } else {
+ mult = 3;
+ div = 4;
+ }
+ hw = clk_hw_register_fixed_factor(NULL, "secdiv", "ahb", 0, mult, div);
+
+ /*
+ * These are the leaf gates, at boot no clocks are gated.
+ */
+ for (i = 0; i < ARRAY_SIZE(gemini_gates); i++) {
+ const struct gemini_gate_data *gd;
+
+ gd = &gemini_gates[i];
+ gemini_clk_data->hws[GEMINI_CLK_GATES + i] =
+ clk_hw_register_gate(NULL, gd->name,
+ gd->parent_name,
+ gd->flags,
+ base + GEMINI_GLOBAL_CLOCK_CONTROL,
+ gd->bit_idx,
+ CLK_GATE_SET_TO_DISABLE,
+ &gemini_clk_lock);
+ }
+
+ /*
+ * The TV Interface Controller has a 5-bit half divider register.
+ * This clock is supposed to be 27MHz as this is an exact multiple
+ * of PAL and NTSC frequencies. The register is undocumented :(
+ * FIXME: figure out the parent and how the divider works.
+ */
+ mult = 1;
+ div = ((val >> TVC_HALFDIV_SHIFT) & TVC_HALFDIV_MASK);
+ dev_dbg(dev, "TVC half divider value = %d\n", div);
+ div += 1;
+ hw = clk_hw_register_fixed_rate(NULL, "tvcdiv", "xtal", 0, 27000000);
+ gemini_clk_data->hws[GEMINI_CLK_TVC] = hw;
+
+ /* FIXME: very unclear what the parent is */
+ hw = gemini_pci_clk_setup("PCI", "xtal", map);
+ gemini_clk_data->hws[GEMINI_CLK_PCI] = hw;
+
+ /* FIXME: very unclear what the parent is */
+ hw = clk_hw_register_fixed_rate(NULL, "uart", "xtal", 0, 48000000);
+ gemini_clk_data->hws[GEMINI_CLK_UART] = hw;
+
+ return 0;
+}
+
+static const struct of_device_id gemini_clk_dt_ids[] = {
+ { .compatible = "cortina,gemini-syscon", },
+ { /* sentinel */ },
+};
+
+static struct platform_driver gemini_clk_driver = {
+ .probe = gemini_clk_probe,
+ .driver = {
+ .name = "gemini-clk",
+ .of_match_table = gemini_clk_dt_ids,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(gemini_clk_driver);
+
+static void __init gemini_cc_init(struct device_node *np)
+{
+ struct regmap *map;
+ struct clk_hw *hw;
+ unsigned long freq;
+ unsigned int mult, div;
+ u32 val;
+ int ret;
+ int i;
+
+ gemini_clk_data = kzalloc(sizeof(*gemini_clk_data) +
+ sizeof(*gemini_clk_data->hws) * GEMINI_NUM_CLKS,
+ GFP_KERNEL);
+ if (!gemini_clk_data)
+ return;
+
+ /*
+ * This way all clock fetched before the platform device probes,
+ * except those we assign here for early use, will be deferred.
+ */
+ for (i = 0; i < GEMINI_NUM_CLKS; i++)
+ gemini_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
+
+ map = syscon_node_to_regmap(np);
+ if (IS_ERR(map)) {
+ pr_err("no syscon regmap\n");
+ return;
+ }
+ /*
+ * We check that the regmap works on this very first access,
+ * but as this is an MMIO-backed regmap, subsequent regmap
+ * access is not going to fail and we skip error checks from
+ * this point.
+ */
+ ret = regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
+ if (ret) {
+ pr_err("failed to read global status register\n");
+ return;
+ }
+
+ /*
+ * XTAL is the crystal oscillator, 60 or 30 MHz selected from
+ * strap pin E6
+ */
+ if (val & PLL_OSC_SEL)
+ freq = 30000000;
+ else
+ freq = 60000000;
+ hw = clk_hw_register_fixed_rate(NULL, "xtal", NULL, 0, freq);
+ pr_debug("main crystal @%lu MHz\n", freq / 1000000);
+
+ /* VCO clock derived from the crystal */
+ mult = 13 + ((val >> AHBSPEED_SHIFT) & AHBSPEED_MASK);
+ div = 2;
+ /* If we run on 30 MHz crystal we have to multiply with two */
+ if (val & PLL_OSC_SEL)
+ mult *= 2;
+ hw = clk_hw_register_fixed_factor(NULL, "vco", "xtal", 0, mult, div);
+
+ /* The AHB clock is always 1/3 of the VCO */
+ hw = clk_hw_register_fixed_factor(NULL, "ahb", "vco", 0, 1, 3);
+ gemini_clk_data->hws[GEMINI_CLK_AHB] = hw;
+
+ /* The APB clock is always 1/6 of the AHB */
+ hw = clk_hw_register_fixed_factor(NULL, "apb", "ahb", 0, 1, 6);
+ gemini_clk_data->hws[GEMINI_CLK_APB] = hw;
+
+ /* Register the clocks to be accessed by the device tree */
+ gemini_clk_data->num = GEMINI_NUM_CLKS;
+ of_clk_add_hw_provider(np, of_clk_hw_onecell_get, gemini_clk_data);
+}
+CLK_OF_DECLARE_DRIVER(gemini_cc, "cortina,gemini-syscon", gemini_cc_init);