diff options
Diffstat (limited to 'drivers/clk/nxp/clk-lpc18xx-ccu.c')
| -rw-r--r-- | drivers/clk/nxp/clk-lpc18xx-ccu.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/drivers/clk/nxp/clk-lpc18xx-ccu.c b/drivers/clk/nxp/clk-lpc18xx-ccu.c new file mode 100644 index 000000000..27781b49e --- /dev/null +++ b/drivers/clk/nxp/clk-lpc18xx-ccu.c @@ -0,0 +1,307 @@ +/* + * Clk driver for NXP LPC18xx/LPC43xx Clock Control Unit (CCU) + * + * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com> + * + * 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) +#define LPC18XX_CCU_DIVSTAT BIT(27) + +/* CCU branch feature bits */ +#define CCU_BRANCH_IS_BUS BIT(0) +#define CCU_BRANCH_HAVE_DIV2 BIT(1) + +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) + continue; + + 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) +{ + const struct clk_hw *parent; + + /* + * The branch clock registers are only accessible + * if the base (parent) clock is enabled. Register + * access with a disabled base clock will hang the + * system. + */ + parent = clk_hw_get_parent(hw); + if (!parent) + return 0; + + if (!clk_hw_is_enabled(parent)) + return 0; + + return clk_gate_ops.is_enabled(hw); +} + +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) + return; + + div->reg = branch->offset + reg_base; + div->flags = CLK_DIVIDER_READ_ONLY; + div->shift = 27; + div->width = 1; + + div_hw = &div->hw; + div_ops = &clk_divider_ro_ops; + } + + branch->gate.reg = branch->offset + reg_base; + branch->gate.bit_idx = 0; + + branch->clk = clk_register_composite(NULL, branch->name, &parent, 1, + NULL, NULL, + div_hw, div_ops, + &branch->gate.hw, &lpc18xx_ccu_gate_ops, 0); + if (IS_ERR(branch->clk)) { + kfree(div); + pr_warn("%s: failed to register %s\n", __func__, branch->name); + return; + } + + /* Grab essential branch clocks for CPU and SDRAM */ + switch (branch->offset) { + case CLK_CPU_EMC: + case CLK_CPU_CORE: + case CLK_CPU_CREG: + case CLK_CPU_EMCDIV: + clk_prepare_enable(branch->clk); + } +} + +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)) + continue; + + lpc18xx_ccu_register_branch_gate_div(&clk_branches[i], reg_base, + parent); + + 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__); + return; + } + + clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL); + if (!clk_data) { + iounmap(reg_base); + return; + } + + 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) { + iounmap(reg_base); + kfree(clk_data); + return; + } + + for (i = 0; i < clk_data->num; i++) { + ret = of_property_read_string_index(np, "clock-names", i, + &clk_data->name[i]); + if (ret) { + pr_warn("%s: failed to get clock name at idx %d\n", + __func__, i); + continue; + } + + 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); |