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clk: Add Gemini SoC clock controller

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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>
This commit is contained in:
Linus Walleij 2017-06-21 09:59:52 +02:00 committed by Stephen Boyd
parent e293915a6e
commit 846423f967
3 changed files with 464 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
drivers/clk/Kconfig
View file

@ -126,6 +126,15 @@ config COMMON_CLK_CS2000_CP
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

1
drivers/clk/Makefile
View file

@ -25,6 +25,7 @@ obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o
obj-$(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

454
drivers/clk/clk-gemini.c Normal file
View file

@ -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);