[PATCH v2 3/4] clk: add lpc18xx ccu clk driver

Joachim Eastwood
2015-04-27T21:38:12Z

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: Joachim Eastwood <manabian@gmail.com>
---
drivers/clk/nxp/Makefile | 1 +
drivers/clk/nxp/clk-lpc18xx-ccu.c | 318 ++++++++++++++++++++++++++++++++
include/dt-bindings/clock/lpc18xx-ccu.h | 74 ++++++++
3 files changed, 393 insertions(+)
create mode 100644 drivers/clk/nxp/clk-lpc18xx-ccu.c
create mode 100644 include/dt-bindings/clock/lpc18xx-ccu.h

diff --git a/drivers/clk/nxp/Makefile b/drivers/clk/nxp/Makefile
index aca9d3e4f7fe..7f608b0ad7b4 100644
--- a/drivers/clk/nxp/Makefile
+++ b/drivers/clk/nxp/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_ARCH_LPC18XX) += clk-lpc18xx-cgu.o
+obj-$(CONFIG_ARCH_LPC18XX) += clk-lpc18xx-ccu.o
diff --git a/drivers/clk/nxp/clk-lpc18xx-ccu.c b/drivers/clk/nxp/clk-lpc18xx-ccu.c
new file mode 100644
index 000000000000..01130f31611c
--- /dev/null
+++ b/drivers/clk/nxp/clk-lpc18xx-ccu.c
@@ -0,0 +1,318 @@
+/*
+ * 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-cgu.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)
+
+#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
+
+struct lpc18xx_branch_clk_data {
+ int *base_ids;
+ int num_base_ids;
+};
+
+struct lpc18xx_clk_branch {
+ int base_id;
+ 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_motorcon_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 int of_clk_get_parent_arg(struct device_node *np, int index)
+{
+ struct of_phandle_args clkspec;
+ int rc;
+
+ if (index < 0)
+ return -EINVAL;
+
+ rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
+ &clkspec);
+ if (rc)
+ return -EINVAL;
+
+ return clkspec.args_count ? clkspec.args[0] : -EINVAL;
+}
+
+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_base_ids; j++) {
+ if (clk_data->base_ids[j] == clk_branches[i].base_id)
+ 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 *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 + base;
+ div->flags = CLK_DIVIDER_READ_ONLY;
+ div->shift = 27;
+ div->width = 1;
+
+ div_hw = &div->hw;
+ div_ops = &clk_divider_ops;
+ }
+
+ branch->gate.reg = branch->offset + 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 *base, int base_clk_id,
+ const char *parent)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(clk_branches); i++) {
+ if (clk_branches[i].base_id != base_clk_id)
+ continue;
+
+ lpc18xx_ccu_register_branch_gate_div(&clk_branches[i], 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;
+ int num_base_ids, *base_ids;
+ void __iomem *base;
+ const char *parent;
+ int base_clk_id;
+ int i;
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ pr_warn("%s: failed to map address range\n", __func__);
+ return;
+ }
+
+ clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+ if (!clk_data)
+ return;
+
+ num_base_ids = of_clk_get_parent_count(np);
+
+ base_ids = kcalloc(num_base_ids, sizeof(int), GFP_KERNEL);
+ if (!base_ids) {
+ kfree(clk_data);
+ return;
+ }
+
+ clk_data->base_ids = base_ids;
+ clk_data->num_base_ids = num_base_ids;
+
+ for (i = 0; i < num_base_ids; i++) {
+ parent = of_clk_get_parent_name(np, i);
+
+ base_clk_id = of_clk_get_parent_arg(np, i);
+ if (base_clk_id < 0 && base_clk_id >= BASE_CLK_MAX) {
+ pr_warn("%s: invalid base clk at idx %d\n", __func__, i);
+ base_ids[i] = -EINVAL;
+ continue;
+ }
+
+ clk_data->base_ids[i] = base_clk_id;
+ lpc18xx_ccu_register_branch_clks(base, base_clk_id, parent);
+ }
+
+ of_clk_add_provider(np, lpc18xx_ccu_branch_clk_get, clk_data);
+}
+CLK_OF_DECLARE(lpc18xx_ccu, "nxp,lpc1850-ccu", lpc18xx_ccu_init);
diff --git a/include/dt-bindings/clock/lpc18xx-ccu.h b/include/dt-bindings/clock/lpc18xx-ccu.h
new file mode 100644
index 000000000000..bbfe00b6ab7d
--- /dev/null
+++ b/include/dt-bindings/clock/lpc18xx-ccu.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * 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
--
1.8.0