Commit 472cd304 authored by Joachim Eastwood's avatar Joachim Eastwood Committed by Michael Turquette

clk: add lpc18xx ccu clk driver

Add driver for NXP LPC18xx/43xx Clock Control Unit (CCU). The CCU
provides fine grained gating of most clocks present in the SoC.
Signed-off-by: default avatarJoachim Eastwood <>
Signed-off-by: default avatarMichael Turquette <>
parent 668c45df
obj-$(CONFIG_ARCH_LPC18XX) += clk-lpc18xx-cgu.o
obj-$(CONFIG_ARCH_LPC18XX) += clk-lpc18xx-ccu.o
* Clk driver for NXP LPC18xx/LPC43xx Clock Control Unit (CCU)
* Copyright (C) 2015 Joachim Eastwood <>
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <dt-bindings/clock/lpc18xx-ccu.h>
/* Bit defines for CCU branch configuration register */
#define LPC18XX_CCU_RUN BIT(0)
#define LPC18XX_CCU_AUTO BIT(1)
#define LPC18XX_CCU_DIV BIT(5)
/* CCU branch feature bits */
#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
struct lpc18xx_branch_clk_data {
const char **name;
int num;
struct lpc18xx_clk_branch {
const char *base_name;
const char *name;
u16 offset;
u16 flags;
struct clk *clk;
struct clk_gate gate;
static struct lpc18xx_clk_branch clk_branches[] = {
{"base_apb3_clk", "apb3_bus", CLK_APB3_BUS, CCU_BRANCH_IS_BUS},
{"base_apb3_clk", "apb3_i2c1", CLK_APB3_I2C1, 0},
{"base_apb3_clk", "apb3_dac", CLK_APB3_DAC, 0},
{"base_apb3_clk", "apb3_adc0", CLK_APB3_ADC0, 0},
{"base_apb3_clk", "apb3_adc1", CLK_APB3_ADC1, 0},
{"base_apb3_clk", "apb3_can0", CLK_APB3_CAN0, 0},
{"base_apb1_clk", "apb1_bus", CLK_APB1_BUS, CCU_BRANCH_IS_BUS},
{"base_apb1_clk", "apb1_mc_pwm", CLK_APB1_MOTOCON_PWM, 0},
{"base_apb1_clk", "apb1_i2c0", CLK_APB1_I2C0, 0},
{"base_apb1_clk", "apb1_i2s", CLK_APB1_I2S, 0},
{"base_apb1_clk", "apb1_can1", CLK_APB1_CAN1, 0},
{"base_spifi_clk", "spifi", CLK_SPIFI, 0},
{"base_cpu_clk", "cpu_bus", CLK_CPU_BUS, CCU_BRANCH_IS_BUS},
{"base_cpu_clk", "cpu_spifi", CLK_CPU_SPIFI, 0},
{"base_cpu_clk", "cpu_gpio", CLK_CPU_GPIO, 0},
{"base_cpu_clk", "cpu_lcd", CLK_CPU_LCD, 0},
{"base_cpu_clk", "cpu_ethernet", CLK_CPU_ETHERNET, 0},
{"base_cpu_clk", "cpu_usb0", CLK_CPU_USB0, 0},
{"base_cpu_clk", "cpu_emc", CLK_CPU_EMC, 0},
{"base_cpu_clk", "cpu_sdio", CLK_CPU_SDIO, 0},
{"base_cpu_clk", "cpu_dma", CLK_CPU_DMA, 0},
{"base_cpu_clk", "cpu_core", CLK_CPU_CORE, 0},
{"base_cpu_clk", "cpu_sct", CLK_CPU_SCT, 0},
{"base_cpu_clk", "cpu_usb1", CLK_CPU_USB1, 0},
{"base_cpu_clk", "cpu_emcdiv", CLK_CPU_EMCDIV, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_flasha", CLK_CPU_FLASHA, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_flashb", CLK_CPU_FLASHB, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_m0app", CLK_CPU_M0APP, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_adchs", CLK_CPU_ADCHS, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_eeprom", CLK_CPU_EEPROM, CCU_BRANCH_HAVE_DIV2},
{"base_cpu_clk", "cpu_wwdt", CLK_CPU_WWDT, 0},
{"base_cpu_clk", "cpu_uart0", CLK_CPU_UART0, 0},
{"base_cpu_clk", "cpu_uart1", CLK_CPU_UART1, 0},
{"base_cpu_clk", "cpu_ssp0", CLK_CPU_SSP0, 0},
{"base_cpu_clk", "cpu_timer0", CLK_CPU_TIMER0, 0},
{"base_cpu_clk", "cpu_timer1", CLK_CPU_TIMER1, 0},
{"base_cpu_clk", "cpu_scu", CLK_CPU_SCU, 0},
{"base_cpu_clk", "cpu_creg", CLK_CPU_CREG, 0},
{"base_cpu_clk", "cpu_ritimer", CLK_CPU_RITIMER, 0},
{"base_cpu_clk", "cpu_uart2", CLK_CPU_UART2, 0},
{"base_cpu_clk", "cpu_uart3", CLK_CPU_UART3, 0},
{"base_cpu_clk", "cpu_timer2", CLK_CPU_TIMER2, 0},
{"base_cpu_clk", "cpu_timer3", CLK_CPU_TIMER3, 0},
{"base_cpu_clk", "cpu_ssp1", CLK_CPU_SSP1, 0},
{"base_cpu_clk", "cpu_qei", CLK_CPU_QEI, 0},
{"base_periph_clk", "periph_bus", CLK_PERIPH_BUS, CCU_BRANCH_IS_BUS},
{"base_periph_clk", "periph_core", CLK_PERIPH_CORE, 0},
{"base_periph_clk", "periph_sgpio", CLK_PERIPH_SGPIO, 0},
{"base_usb0_clk", "usb0", CLK_USB0, 0},
{"base_usb1_clk", "usb1", CLK_USB1, 0},
{"base_spi_clk", "spi", CLK_SPI, 0},
{"base_adchs_clk", "adchs", CLK_ADCHS, 0},
{"base_audio_clk", "audio", CLK_AUDIO, 0},
{"base_uart3_clk", "apb2_uart3", CLK_APB2_UART3, 0},
{"base_uart2_clk", "apb2_uart2", CLK_APB2_UART2, 0},
{"base_uart1_clk", "apb0_uart1", CLK_APB0_UART1, 0},
{"base_uart0_clk", "apb0_uart0", CLK_APB0_UART0, 0},
{"base_ssp1_clk", "apb2_ssp1", CLK_APB2_SSP1, 0},
{"base_ssp0_clk", "apb0_ssp0", CLK_APB0_SSP0, 0},
{"base_sdio_clk", "sdio", CLK_SDIO, 0},
static struct clk *lpc18xx_ccu_branch_clk_get(struct of_phandle_args *clkspec,
void *data)
struct lpc18xx_branch_clk_data *clk_data = data;
unsigned int offset = clkspec->args[0];
int i, j;
for (i = 0; i < ARRAY_SIZE(clk_branches); i++) {
if (clk_branches[i].offset != offset)
for (j = 0; j < clk_data->num; j++) {
if (!strcmp(clk_branches[i].base_name, clk_data->name[j]))
return clk_branches[i].clk;
pr_err("%s: invalid clock offset %d\n", __func__, offset);
return ERR_PTR(-EINVAL);
static int lpc18xx_ccu_gate_endisable(struct clk_hw *hw, bool enable)
struct clk_gate *gate = to_clk_gate(hw);
u32 val;
* Divider field is write only, so divider stat field must
* be read so divider field can be set accordingly.
val = clk_readl(gate->reg);
if (val & LPC18XX_CCU_DIVSTAT)
val |= LPC18XX_CCU_DIV;
if (enable) {
val |= LPC18XX_CCU_RUN;
} else {
* To safely disable a branch clock a squence of two separate
* writes must be used. First write should set the AUTO bit
* and the next write should clear the RUN bit.
val |= LPC18XX_CCU_AUTO;
clk_writel(val, gate->reg);
val &= ~LPC18XX_CCU_RUN;
clk_writel(val, gate->reg);
return 0;
static int lpc18xx_ccu_gate_enable(struct clk_hw *hw)
return lpc18xx_ccu_gate_endisable(hw, true);
static void lpc18xx_ccu_gate_disable(struct clk_hw *hw)
lpc18xx_ccu_gate_endisable(hw, false);
static int lpc18xx_ccu_gate_is_enabled(struct clk_hw *hw)
struct clk_gate *gate = to_clk_gate(hw);
return clk_readl(gate->reg) & LPC18XX_CCU_RUN;
static const struct clk_ops lpc18xx_ccu_gate_ops = {
.enable = lpc18xx_ccu_gate_enable,
.disable = lpc18xx_ccu_gate_disable,
.is_enabled = lpc18xx_ccu_gate_is_enabled,
static void lpc18xx_ccu_register_branch_gate_div(struct lpc18xx_clk_branch *branch,
void __iomem *reg_base,
const char *parent)
const struct clk_ops *div_ops = NULL;
struct clk_divider *div = NULL;
struct clk_hw *div_hw = NULL;
if (branch->flags & CCU_BRANCH_HAVE_DIV2) {
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
div->reg = branch->offset + reg_base;
div->shift = 27;
div->width = 1;
div_hw = &div->hw;
div_ops = &clk_divider_ops;
branch->gate.reg = branch->offset + reg_base;
branch->gate.bit_idx = 0;
branch->clk = clk_register_composite(NULL, branch->name, &parent, 1,
div_hw, div_ops,
&branch->gate.hw, &lpc18xx_ccu_gate_ops, 0);
if (IS_ERR(branch->clk)) {
pr_warn("%s: failed to register %s\n", __func__, branch->name);
/* Grab essential branch clocks for CPU and SDRAM */
switch (branch->offset) {
static void lpc18xx_ccu_register_branch_clks(void __iomem *reg_base,
const char *base_name)
const char *parent = base_name;
int i;
for (i = 0; i < ARRAY_SIZE(clk_branches); i++) {
if (strcmp(clk_branches[i].base_name, base_name))
lpc18xx_ccu_register_branch_gate_div(&clk_branches[i], reg_base,
if (clk_branches[i].flags & CCU_BRANCH_IS_BUS)
parent = clk_branches[i].name;
static void __init lpc18xx_ccu_init(struct device_node *np)
struct lpc18xx_branch_clk_data *clk_data;
void __iomem *reg_base;
int i, ret;
reg_base = of_iomap(np, 0);
if (!reg_base) {
pr_warn("%s: failed to map address range\n", __func__);
clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
if (!clk_data)
clk_data->num = of_property_count_strings(np, "clock-names");
clk_data->name = kcalloc(clk_data->num, sizeof(char *), GFP_KERNEL);
if (!clk_data->name) {
for (i = 0; i < clk_data->num; i++) {
ret = of_property_read_string_index(np, "clock-names", i,
if (ret) {
pr_warn("%s: failed to get clock name at idx %d\n",
__func__, i);
lpc18xx_ccu_register_branch_clks(reg_base, clk_data->name[i]);
of_clk_add_provider(np, lpc18xx_ccu_branch_clk_get, clk_data);
CLK_OF_DECLARE(lpc18xx_ccu, "nxp,lpc1850-ccu", lpc18xx_ccu_init);
* Copyright (c) 2015 Joachim Eastwood <>
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
* Released under the terms of 3-clause BSD License
* Released under the terms of GNU General Public License Version 2.0
/* Clock Control Unit 1 (CCU1) clock offsets */
#define CLK_APB3_BUS 0x100
#define CLK_APB3_I2C1 0x108
#define CLK_APB3_DAC 0x110
#define CLK_APB3_ADC0 0x118
#define CLK_APB3_ADC1 0x120
#define CLK_APB3_CAN0 0x128
#define CLK_APB1_BUS 0x200
#define CLK_APB1_MOTOCON_PWM 0x208
#define CLK_APB1_I2C0 0x210
#define CLK_APB1_I2S 0x218
#define CLK_APB1_CAN1 0x220
#define CLK_SPIFI 0x300
#define CLK_CPU_BUS 0x400
#define CLK_CPU_SPIFI 0x408
#define CLK_CPU_GPIO 0x410
#define CLK_CPU_LCD 0x418
#define CLK_CPU_ETHERNET 0x420
#define CLK_CPU_USB0 0x428
#define CLK_CPU_EMC 0x430
#define CLK_CPU_SDIO 0x438
#define CLK_CPU_DMA 0x440
#define CLK_CPU_CORE 0x448
#define CLK_CPU_SCT 0x468
#define CLK_CPU_USB1 0x470
#define CLK_CPU_EMCDIV 0x478
#define CLK_CPU_FLASHA 0x480
#define CLK_CPU_FLASHB 0x488
#define CLK_CPU_M0APP 0x490
#define CLK_CPU_ADCHS 0x498
#define CLK_CPU_EEPROM 0x4a0
#define CLK_CPU_WWDT 0x500
#define CLK_CPU_UART0 0x508
#define CLK_CPU_UART1 0x510
#define CLK_CPU_SSP0 0x518
#define CLK_CPU_TIMER0 0x520
#define CLK_CPU_TIMER1 0x528
#define CLK_CPU_SCU 0x530
#define CLK_CPU_CREG 0x538
#define CLK_CPU_RITIMER 0x600
#define CLK_CPU_UART2 0x608
#define CLK_CPU_UART3 0x610
#define CLK_CPU_TIMER2 0x618
#define CLK_CPU_TIMER3 0x620
#define CLK_CPU_SSP1 0x628
#define CLK_CPU_QEI 0x630
#define CLK_PERIPH_BUS 0x700
#define CLK_PERIPH_CORE 0x710
#define CLK_PERIPH_SGPIO 0x718
#define CLK_USB0 0x800
#define CLK_USB1 0x900
#define CLK_SPI 0xA00
#define CLK_ADCHS 0xB00
/* Clock Control Unit 2 (CCU2) clock offsets */
#define CLK_AUDIO 0x100
#define CLK_APB2_UART3 0x200
#define CLK_APB2_UART2 0x300
#define CLK_APB0_UART1 0x400
#define CLK_APB0_UART0 0x500
#define CLK_APB2_SSP1 0x600
#define CLK_APB0_SSP0 0x700
#define CLK_SDIO 0x800
Markdown is supported
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment