MIPS: lantiq: implement support for clkdev api

This patch unifies all clock generation and gating code into one file.
All drivers will now be able to request their clocks via their device.
This patch also adds support for the clockout feature, which allows
clock generation on external pins.

Support for COMMON_CLK will be provided in the next series.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3804/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 367 insertions, 0 deletions

diff --git a/arch/mips/lantiq/xway/sysctrl.c b/arch/mips/lantiq/xway/sysctrl.c
new file mode 100644
index 000000000000..4d6aac693535
--- /dev/null
+++ b/arch/mips/lantiq/xway/sysctrl.c
@@ -0,0 +1,367 @@
+/*
+ *  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.
+ *
+ *  Copyright (C) 2011-2012 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/ioport.h>
+#include <linux/export.h>
+#include <linux/clkdev.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+
+#include <lantiq_soc.h>
+
+#include "../clk.h"
+#include "../prom.h"
+
+/* clock control register */
+#define CGU_IFCCR	0x0018
+/* system clock register */
+#define CGU_SYS		0x0010
+/* pci control register */
+#define CGU_PCICR	0x0034
+/* ephy configuration register */
+#define CGU_EPHY	0x10
+/* power control register */
+#define PMU_PWDCR	0x1C
+/* power status register */
+#define PMU_PWDSR	0x20
+/* power control register */
+#define PMU_PWDCR1	0x24
+/* power status register */
+#define PMU_PWDSR1	0x28
+/* power control register */
+#define PWDCR(x) ((x) ? (PMU_PWDCR1) : (PMU_PWDCR))
+/* power status register */
+#define PWDSR(x) ((x) ? (PMU_PWDSR1) : (PMU_PWDSR))
+
+/* clock gates that we can en/disable */
+#define PMU_USB0_P	BIT(0)
+#define PMU_PCI		BIT(4)
+#define PMU_USB0	BIT(6)
+#define PMU_ASC0	BIT(7)
+#define PMU_EPHY	BIT(7)	/* ase */
+#define PMU_SPI		BIT(8)
+#define PMU_DFE		BIT(9)
+#define PMU_EBU		BIT(10)
+#define PMU_STP		BIT(11)
+#define PMU_AHBS	BIT(13) /* vr9 */
+#define PMU_AHBM	BIT(15)
+#define PMU_ASC1	BIT(17)
+#define PMU_PPE_QSB	BIT(18)
+#define PMU_PPE_SLL01	BIT(19)
+#define PMU_PPE_TC	BIT(21)
+#define PMU_PPE_EMA	BIT(22)
+#define PMU_PPE_DPLUM	BIT(23)
+#define PMU_PPE_DPLUS	BIT(24)
+#define PMU_USB1_P	BIT(26)
+#define PMU_USB1	BIT(27)
+#define PMU_PPE_TOP	BIT(29)
+#define PMU_GPHY	BIT(30)
+#define PMU_PCIE_CLK	BIT(31)
+
+#define PMU1_PCIE_PHY	BIT(0)
+#define PMU1_PCIE_CTL	BIT(1)
+#define PMU1_PCIE_PDI	BIT(4)
+#define PMU1_PCIE_MSI	BIT(5)
+
+#define pmu_w32(x, y)	ltq_w32((x), pmu_membase + (y))
+#define pmu_r32(x)	ltq_r32(pmu_membase + (x))
+
+static void __iomem *pmu_membase;
+void __iomem *ltq_cgu_membase;
+void __iomem *ltq_ebu_membase;
+
+/* legacy function kept alive to ease clkdev transition */
+void ltq_pmu_enable(unsigned int module)
+{
+	int err = 1000000;
+
+	pmu_w32(pmu_r32(PMU_PWDCR) & ~module, PMU_PWDCR);
+	do {} while (--err && (pmu_r32(PMU_PWDSR) & module));
+
+	if (!err)
+		panic("activating PMU module failed!");
+}
+EXPORT_SYMBOL(ltq_pmu_enable);
+
+/* legacy function kept alive to ease clkdev transition */
+void ltq_pmu_disable(unsigned int module)
+{
+	pmu_w32(pmu_r32(PMU_PWDCR) | module, PMU_PWDCR);
+}
+EXPORT_SYMBOL(ltq_pmu_disable);
+
+/* enable a hw clock */
+static int cgu_enable(struct clk *clk)
+{
+	ltq_cgu_w32(ltq_cgu_r32(CGU_IFCCR) | clk->bits, CGU_IFCCR);
+	return 0;
+}
+
+/* disable a hw clock */
+static void cgu_disable(struct clk *clk)
+{
+	ltq_cgu_w32(ltq_cgu_r32(CGU_IFCCR) & ~clk->bits, CGU_IFCCR);
+}
+
+/* enable a clock gate */
+static int pmu_enable(struct clk *clk)
+{
+	int retry = 1000000;
+
+	pmu_w32(pmu_r32(PWDCR(clk->module)) & ~clk->bits,
+		PWDCR(clk->module));
+	do {} while (--retry && (pmu_r32(PWDSR(clk->module)) & clk->bits));
+
+	if (!retry)
+		panic("activating PMU module failed!\n");
+
+	return 0;
+}
+
+/* disable a clock gate */
+static void pmu_disable(struct clk *clk)
+{
+	pmu_w32(pmu_r32(PWDCR(clk->module)) | clk->bits,
+		PWDCR(clk->module));
+}
+
+/* the pci enable helper */
+static int pci_enable(struct clk *clk)
+{
+	unsigned int ifccr = ltq_cgu_r32(CGU_IFCCR);
+	/* set bus clock speed */
+	if (of_machine_is_compatible("lantiq,ar9")) {
+		ifccr &= ~0x1f00000;
+		if (clk->rate == CLOCK_33M)
+			ifccr |= 0xe00000;
+		else
+			ifccr |= 0x700000; /* 62.5M */
+	} else {
+		ifccr &= ~0xf00000;
+		if (clk->rate == CLOCK_33M)
+			ifccr |= 0x800000;
+		else
+			ifccr |= 0x400000; /* 62.5M */
+	}
+	ltq_cgu_w32(ifccr, CGU_IFCCR);
+	pmu_enable(clk);
+	return 0;
+}
+
+/* enable the external clock as a source */
+static int pci_ext_enable(struct clk *clk)
+{
+	ltq_cgu_w32(ltq_cgu_r32(CGU_IFCCR) & ~(1 << 16),
+		CGU_IFCCR);
+	ltq_cgu_w32((1 << 30), CGU_PCICR);
+	return 0;
+}
+
+/* disable the external clock as a source */
+static void pci_ext_disable(struct clk *clk)
+{
+	ltq_cgu_w32(ltq_cgu_r32(CGU_IFCCR) | (1 << 16),
+		CGU_IFCCR);
+	ltq_cgu_w32((1 << 31) | (1 << 30), CGU_PCICR);
+}
+
+/* enable a clockout source */
+static int clkout_enable(struct clk *clk)
+{
+	int i;
+
+	/* get the correct rate */
+	for (i = 0; i < 4; i++) {
+		if (clk->rates[i] == clk->rate) {
+			int shift = 14 - (2 * clk->module);
+			unsigned int ifccr = ltq_cgu_r32(CGU_IFCCR);
+
+			ifccr &= ~(3 << shift);
+			ifccr |= i << shift;
+			ltq_cgu_w32(ifccr, CGU_IFCCR);
+			return 0;
+		}
+	}
+	return -1;
+}
+
+/* manage the clock gates via PMU */
+static void clkdev_add_pmu(const char *dev, const char *con,
+					unsigned int module, unsigned int bits)
+{
+	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+
+	clk->cl.dev_id = dev;
+	clk->cl.con_id = con;
+	clk->cl.clk = clk;
+	clk->enable = pmu_enable;
+	clk->disable = pmu_disable;
+	clk->module = module;
+	clk->bits = bits;
+	clkdev_add(&clk->cl);
+}
+
+/* manage the clock generator */
+static void clkdev_add_cgu(const char *dev, const char *con,
+					unsigned int bits)
+{
+	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+
+	clk->cl.dev_id = dev;
+	clk->cl.con_id = con;
+	clk->cl.clk = clk;
+	clk->enable = cgu_enable;
+	clk->disable = cgu_disable;
+	clk->bits = bits;
+	clkdev_add(&clk->cl);
+}
+
+/* pci needs its own enable function as the setup is a bit more complex */
+static unsigned long valid_pci_rates[] = {CLOCK_33M, CLOCK_62_5M, 0};
+
+static void clkdev_add_pci(void)
+{
+	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+	struct clk *clk_ext = kzalloc(sizeof(struct clk), GFP_KERNEL);
+
+	/* main pci clock */
+	clk->cl.dev_id = "17000000.pci";
+	clk->cl.con_id = NULL;
+	clk->cl.clk = clk;
+	clk->rate = CLOCK_33M;
+	clk->rates = valid_pci_rates;
+	clk->enable = pci_enable;
+	clk->disable = pmu_disable;
+	clk->module = 0;
+	clk->bits = PMU_PCI;
+	clkdev_add(&clk->cl);
+
+	/* use internal/external bus clock */
+	clk_ext->cl.dev_id = "17000000.pci";
+	clk_ext->cl.con_id = "external";
+	clk_ext->cl.clk = clk_ext;
+	clk_ext->enable = pci_ext_enable;
+	clk_ext->disable = pci_ext_disable;
+	clkdev_add(&clk_ext->cl);
+}
+
+/* xway socs can generate clocks on gpio pins */
+static unsigned long valid_clkout_rates[4][5] = {
+	{CLOCK_32_768K, CLOCK_1_536M, CLOCK_2_5M, CLOCK_12M, 0},
+	{CLOCK_40M, CLOCK_12M, CLOCK_24M, CLOCK_48M, 0},
+	{CLOCK_25M, CLOCK_40M, CLOCK_30M, CLOCK_60M, 0},
+	{CLOCK_12M, CLOCK_50M, CLOCK_32_768K, CLOCK_25M, 0},
+};
+
+static void clkdev_add_clkout(void)
+{
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		struct clk *clk;
+		char *name;
+
+		name = kzalloc(sizeof("clkout0"), GFP_KERNEL);
+		sprintf(name, "clkout%d", i);
+
+		clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+		clk->cl.dev_id = "1f103000.cgu";
+		clk->cl.con_id = name;
+		clk->cl.clk = clk;
+		clk->rate = 0;
+		clk->rates = valid_clkout_rates[i];
+		clk->enable = clkout_enable;
+		clk->module = i;
+		clkdev_add(&clk->cl);
+	}
+}
+
+/* bring up all register ranges that we need for basic system control */
+void __init ltq_soc_init(void)
+{
+	struct resource res_pmu, res_cgu, res_ebu;
+	struct device_node *np_pmu =
+			of_find_compatible_node(NULL, NULL, "lantiq,pmu-xway");
+	struct device_node *np_cgu =
+			of_find_compatible_node(NULL, NULL, "lantiq,cgu-xway");
+	struct device_node *np_ebu =
+			of_find_compatible_node(NULL, NULL, "lantiq,ebu-xway");
+
+	/* check if all the core register ranges are available */
+	if (!np_pmu || !np_cgu || !np_ebu)
+		panic("Failed to load core nodess from devicetree");
+
+	if (of_address_to_resource(np_pmu, 0, &res_pmu) ||
+			of_address_to_resource(np_cgu, 0, &res_cgu) ||
+			of_address_to_resource(np_ebu, 0, &res_ebu))
+		panic("Failed to get core resources");
+
+	if ((request_mem_region(res_pmu.start, resource_size(&res_pmu),
+				res_pmu.name) < 0) ||
+		(request_mem_region(res_cgu.start, resource_size(&res_cgu),
+				res_cgu.name) < 0) ||
+		(request_mem_region(res_ebu.start, resource_size(&res_ebu),
+				res_ebu.name) < 0))
+		pr_err("Failed to request core reources");
+
+	pmu_membase = ioremap_nocache(res_pmu.start, resource_size(&res_pmu));
+	ltq_cgu_membase = ioremap_nocache(res_cgu.start,
+						resource_size(&res_cgu));
+	ltq_ebu_membase = ioremap_nocache(res_ebu.start,
+						resource_size(&res_ebu));
+	if (!pmu_membase || !ltq_cgu_membase || !ltq_ebu_membase)
+		panic("Failed to remap core resources");
+
+	/* make sure to unprotect the memory region where flash is located */
+	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_BUSCON0) & ~EBU_WRDIS, LTQ_EBU_BUSCON0);
+
+	/* add our generic xway clocks */
+	clkdev_add_pmu("10000000.fpi", NULL, 0, PMU_FPI);
+	clkdev_add_pmu("1e100400.serial", NULL, 0, PMU_ASC0);
+	clkdev_add_pmu("1e100a00.gptu", NULL, 0, PMU_GPT);
+	clkdev_add_pmu("1e100bb0.stp", NULL, 0, PMU_STP);
+	clkdev_add_pmu("1e104100.dma", NULL, 0, PMU_DMA);
+	clkdev_add_pmu("1e100800.spi", NULL, 0, PMU_SPI);
+	clkdev_add_pmu("1e105300.ebu", NULL, 0, PMU_EBU);
+	clkdev_add_clkout();
+
+	/* add the soc dependent clocks */
+	if (!of_machine_is_compatible("lantiq,vr9"))
+		clkdev_add_pmu("1e180000.etop", NULL, 0, PMU_PPE);
+
+	if (!of_machine_is_compatible("lantiq,ase")) {
+		clkdev_add_pmu("1e100c00.serial", NULL, 0, PMU_ASC1);
+		clkdev_add_pci();
+	}
+
+	if (of_machine_is_compatible("lantiq,ase")) {
+		if (ltq_cgu_r32(CGU_SYS) & (1 << 5))
+			clkdev_add_static(CLOCK_266M, CLOCK_133M, CLOCK_133M);
+		else
+			clkdev_add_static(CLOCK_133M, CLOCK_133M, CLOCK_133M);
+		clkdev_add_cgu("1e180000.etop", "ephycgu", CGU_EPHY),
+		clkdev_add_pmu("1e180000.etop", "ephy", 0, PMU_EPHY);
+	} else if (of_machine_is_compatible("lantiq,vr9")) {
+		clkdev_add_static(ltq_vr9_cpu_hz(), ltq_vr9_fpi_hz(),
+				ltq_vr9_fpi_hz());
+		clkdev_add_pmu("1d900000.pcie", "phy", 1, PMU1_PCIE_PHY);
+		clkdev_add_pmu("1d900000.pcie", "bus", 0, PMU_PCIE_CLK);
+		clkdev_add_pmu("1d900000.pcie", "msi", 1, PMU1_PCIE_MSI);
+		clkdev_add_pmu("1d900000.pcie", "pdi", 1, PMU1_PCIE_PDI);
+		clkdev_add_pmu("1d900000.pcie", "ctl", 1, PMU1_PCIE_CTL);
+		clkdev_add_pmu("1d900000.pcie", "ahb", 0, PMU_AHBM | PMU_AHBS);
+	} else if (of_machine_is_compatible("lantiq,ar9")) {
+		clkdev_add_static(ltq_ar9_cpu_hz(), ltq_ar9_fpi_hz(),
+				ltq_ar9_fpi_hz());
+		clkdev_add_pmu("1e180000.etop", "switch", 0, PMU_SWITCH);
+	} else {
+		clkdev_add_static(ltq_danube_cpu_hz(), ltq_danube_fpi_hz(),
+				ltq_danube_fpi_hz());
+	}
+}