[PATCH v8 1/2] pinctrl: pinctrl-loongson2: add pinctrl driver support

[Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>]

The Loongson-2 SoC has a few pins that can be used as GPIOs or take
multiple other functions. Add a driver for the pinmuxing.

There is currently no support for GPIO pin pull-up and pull-down.

Signed-off-by: zhanghongchen <zhanghongchen@xxxxxxxxxxx>
Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
---
Change in v8:
		1. Add #include <linux/pinctrl/pinctrl.h>.
		2. Add #include <linux/seq_file.h>. 
Change in v7:
		1. Add all history change log information.
Change in v6:
		1. Add #include <asm-generic/io.h>.
Change in v5:
		1. NO change, but other patch in this series of patches set has
		   change.
Change in v4:
		1. Replace Loongson2/loongson2 with Loongson-2/loongson-2/LOONGSON-2
		   but except c file.
		2. Add a helper combining two calls and that helper is
		   "devm_platform_ioremap_resource". 
Change in v3:
		1. NO change, but other patch in this series of patches set has
		   change.
Change in v2:
		1. Add "depends LOONGARCH || COMPILE_TEST" in Kconfig.
		2. Fixup the odd indentation in Kconfig.
		3. Make coma goes to previous line. in Kconfig.
		4. Add items in alphabetical order in Makefile. 
		5. Add const type for loongson2_pmx_functions.
		6. Add static for loongson2_pmx_ops.
		7. Replace sizeof(struct loongson2_pinctrl) with sizeof(*pctrl).
		8. Use dev_err_probe as helper to replace "dev_err" and 
		   "return PTR_ERR()".
		9. Replace raw spinlock with ordinary spinlock.

 MAINTAINERS                         |   7 +
 drivers/pinctrl/Kconfig             |  11 +
 drivers/pinctrl/Makefile            |   1 +
 drivers/pinctrl/pinctrl-loongson2.c | 331 ++++++++++++++++++++++++++++
 4 files changed, 350 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-loongson2.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 6234b5c57a9a..7c71cf2a6ddd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12036,6 +12036,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/timer/loongson,ls2k-hpet.yaml
 F:	drivers/clocksource/loongson2_hpet.c
 
+LOONGSON-2 SOC SERIES PINCTRL DRIVER
+M:	zhanghongchen <zhanghongchen@xxxxxxxxxxx>
+M:	Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
+L:	linux-gpio@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	drivers/pinctrl/pinctrl-loongson2.c
+
 LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
 M:	Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
 M:	Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index f71fefff400f..a053952e2482 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -512,6 +512,17 @@ config PINCTRL_ZYNQMP
 	  This driver can also be built as a module. If so, the module
 	  will be called pinctrl-zynqmp.
 
+config PINCTRL_LOONGSON2
+	tristate "Pinctrl driver for the Loongson-2 SoC"
+	depends on LOONGARCH || COMPILE_TEST
+	select PINMUX
+	select GENERIC_PINCONF
+	help
+	  This selects pin control driver for the Loongson-2 SoC. It
+	  provides pin config functions multiplexing.  GPIO pin pull-up,
+	  pull-down functions are not supported. Say yes to enable
+	  pinctrl for Loongson-2 SoC.
+
 source "drivers/pinctrl/actions/Kconfig"
 source "drivers/pinctrl/aspeed/Kconfig"
 source "drivers/pinctrl/bcm/Kconfig"
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 89bfa01b5231..37b1f9bb85e5 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_PINCTRL_KEEMBAY)	+= pinctrl-keembay.o
 obj-$(CONFIG_PINCTRL_LANTIQ)	+= pinctrl-lantiq.o
 obj-$(CONFIG_PINCTRL_FALCON)	+= pinctrl-falcon.o
 obj-$(CONFIG_PINCTRL_XWAY)	+= pinctrl-xway.o
+obj-$(CONFIG_PINCTRL_LOONGSON2) += pinctrl-loongson2.o
 obj-$(CONFIG_PINCTRL_LPC18XX)	+= pinctrl-lpc18xx.o
 obj-$(CONFIG_PINCTRL_MAX77620)	+= pinctrl-max77620.o
 obj-$(CONFIG_PINCTRL_MCP23S08_I2C)	+= pinctrl-mcp23s08_i2c.o
diff --git a/drivers/pinctrl/pinctrl-loongson2.c b/drivers/pinctrl/pinctrl-loongson2.c
new file mode 100644
index 000000000000..8d2813cb60cf
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-loongson2.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: zhanghongchen <zhanghongchen@xxxxxxxxxxx>
+ *         Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/seq_file.h>
+#include <asm-generic/io.h>
+#include "core.h"
+#include "pinctrl-utils.h"
+
+#define PMX_GROUP(grp, offset, bitv)					\
+	{								\
+		.name = #grp,						\
+		.pins = grp ## _pins,					\
+		.num_pins = ARRAY_SIZE(grp ## _pins),			\
+		.reg = offset,						\
+		.bit = bitv,						\
+	}
+
+#define SPECIFIC_GROUP(group)						\
+	static const char * const group##_groups[] = {			\
+		#group							\
+	}
+
+#define FUNCTION(fn)							\
+	{								\
+		.name = #fn,						\
+		.groups = fn ## _groups,				\
+		.num_groups = ARRAY_SIZE(fn ## _groups),		\
+	}
+
+struct loongson2_pinctrl {
+	struct device *dev;
+	struct pinctrl_dev *pcdev;
+	struct pinctrl_desc desc;
+	struct device_node *of_node;
+	spinlock_t lock;
+	void * __iomem reg_base;
+};
+
+struct loongson2_pmx_group {
+	const char *name;
+	const unsigned int *pins;
+	unsigned int num_pins;
+	unsigned int reg;
+	unsigned int bit;
+};
+
+struct loongson2_pmx_func {
+	const char *name;
+	const char * const *groups;
+	unsigned int num_groups;
+};
+
+#define LOONGSON2_PIN(x) PINCTRL_PIN(x, "gpio"#x)
+static const struct pinctrl_pin_desc loongson2_pctrl_pins[] = {
+	LOONGSON2_PIN(0),  LOONGSON2_PIN(1),  LOONGSON2_PIN(2),  LOONGSON2_PIN(3),
+	LOONGSON2_PIN(4),  LOONGSON2_PIN(5),  LOONGSON2_PIN(6),  LOONGSON2_PIN(7),
+	LOONGSON2_PIN(8),  LOONGSON2_PIN(9),  LOONGSON2_PIN(10), LOONGSON2_PIN(11),
+	LOONGSON2_PIN(12), LOONGSON2_PIN(13), LOONGSON2_PIN(14),
+	LOONGSON2_PIN(16), LOONGSON2_PIN(17), LOONGSON2_PIN(18), LOONGSON2_PIN(19),
+	LOONGSON2_PIN(20), LOONGSON2_PIN(21), LOONGSON2_PIN(22), LOONGSON2_PIN(23),
+	LOONGSON2_PIN(24), LOONGSON2_PIN(25), LOONGSON2_PIN(26), LOONGSON2_PIN(27),
+	LOONGSON2_PIN(28), LOONGSON2_PIN(29), LOONGSON2_PIN(30),
+	LOONGSON2_PIN(32), LOONGSON2_PIN(33), LOONGSON2_PIN(34), LOONGSON2_PIN(35),
+	LOONGSON2_PIN(36), LOONGSON2_PIN(37), LOONGSON2_PIN(38), LOONGSON2_PIN(39),
+	LOONGSON2_PIN(40), LOONGSON2_PIN(41),
+	LOONGSON2_PIN(44), LOONGSON2_PIN(45), LOONGSON2_PIN(46), LOONGSON2_PIN(47),
+	LOONGSON2_PIN(48), LOONGSON2_PIN(49), LOONGSON2_PIN(50), LOONGSON2_PIN(51),
+	LOONGSON2_PIN(52), LOONGSON2_PIN(53), LOONGSON2_PIN(54), LOONGSON2_PIN(55),
+	LOONGSON2_PIN(56), LOONGSON2_PIN(57), LOONGSON2_PIN(58), LOONGSON2_PIN(59),
+	LOONGSON2_PIN(60), LOONGSON2_PIN(61), LOONGSON2_PIN(62), LOONGSON2_PIN(63),
+};
+
+static const unsigned int gpio_pins[] = {0, 1, 2, 3, 4, 5, 6, 7,
+					 8, 9, 10, 11, 12, 13, 14,
+					 16, 17, 18, 19, 20, 21, 22, 23,
+					 24, 25, 26, 27, 28, 29, 30,
+					 32, 33, 34, 35, 36, 37, 38, 39,
+					 40,         43, 44, 45, 46, 47,
+					 48, 49, 50, 51, 52, 53, 46, 55,
+					 56, 57, 58, 59, 60, 61, 62, 63};
+static const unsigned int sdio_pins[] = {36, 37, 38, 39, 40, 41};
+static const unsigned int can1_pins[] = {34, 35};
+static const unsigned int can0_pins[] = {32, 33};
+static const unsigned int pwm3_pins[] = {23};
+static const unsigned int pwm2_pins[] = {22};
+static const unsigned int pwm1_pins[] = {21};
+static const unsigned int pwm0_pins[] = {20};
+static const unsigned int i2c1_pins[] = {18, 19};
+static const unsigned int i2c0_pins[] = {16, 17};
+static const unsigned int nand_pins[] = {44, 45, 46, 47, 48, 49, 50, 51,
+					 52, 53, 54, 55, 56, 57, 58, 59, 60,
+					 61, 62, 63};
+static const unsigned int sata_led_pins[] = {14};
+static const unsigned int lio_pins[]    = {};
+static const unsigned int i2s_pins[]    = {24, 25, 26, 27, 28};
+static const unsigned int hda_pins[]    = {24, 25, 26, 27, 28, 29, 30};
+static const unsigned int uart2_pins[]  = {};
+static const unsigned int uart1_pins[]  = {};
+static const unsigned int camera_pins[] = {};
+static const unsigned int dvo1_pins[]   = {};
+static const unsigned int dvo0_pins[]   = {};
+
+static struct loongson2_pmx_group loongson2_pmx_groups[] = {
+	PMX_GROUP(gpio, 0x0, 64),
+	PMX_GROUP(sdio, 0x0, 20),
+	PMX_GROUP(can1, 0x0, 17),
+	PMX_GROUP(can0, 0x0, 16),
+	PMX_GROUP(pwm3, 0x0, 15),
+	PMX_GROUP(pwm2, 0x0, 14),
+	PMX_GROUP(pwm1, 0x0, 13),
+	PMX_GROUP(pwm0, 0x0, 12),
+	PMX_GROUP(i2c1, 0x0, 11),
+	PMX_GROUP(i2c0, 0x0, 10),
+	PMX_GROUP(nand, 0x0, 9),
+	PMX_GROUP(sata_led, 0x0, 8),
+	PMX_GROUP(lio, 0x0, 7),
+	PMX_GROUP(i2s, 0x0, 6),
+	PMX_GROUP(hda, 0x0, 4),
+	PMX_GROUP(uart2, 0x8, 13),
+	PMX_GROUP(uart1, 0x8, 12),
+	PMX_GROUP(camera, 0x10, 5),
+	PMX_GROUP(dvo1, 0x10, 4),
+	PMX_GROUP(dvo0, 0x10, 1),
+
+};
+
+SPECIFIC_GROUP(sdio);
+SPECIFIC_GROUP(can1);
+SPECIFIC_GROUP(can0);
+SPECIFIC_GROUP(pwm3);
+SPECIFIC_GROUP(pwm2);
+SPECIFIC_GROUP(pwm1);
+SPECIFIC_GROUP(pwm0);
+SPECIFIC_GROUP(i2c1);
+SPECIFIC_GROUP(i2c0);
+SPECIFIC_GROUP(nand);
+SPECIFIC_GROUP(sata_led);
+SPECIFIC_GROUP(lio);
+SPECIFIC_GROUP(i2s);
+SPECIFIC_GROUP(hda);
+SPECIFIC_GROUP(uart2);
+SPECIFIC_GROUP(uart1);
+SPECIFIC_GROUP(camera);
+SPECIFIC_GROUP(dvo1);
+SPECIFIC_GROUP(dvo0);
+
+static const char * const gpio_groups[] = {
+	"sdio", "can1", "can0", "pwm3", "pwm2", "pwm1", "pwm0", "i2c1",
+	"i2c0", "nand", "sata_led", "lio", "i2s", "hda", "uart2", "uart1",
+	"camera", "dvo1", "dvo0"
+};
+
+static const struct loongson2_pmx_func loongson2_pmx_functions[] = {
+	FUNCTION(gpio),
+	FUNCTION(sdio),
+	FUNCTION(can1),
+	FUNCTION(can0),
+	FUNCTION(pwm3),
+	FUNCTION(pwm2),
+	FUNCTION(pwm1),
+	FUNCTION(pwm0),
+	FUNCTION(i2c1),
+	FUNCTION(i2c0),
+	FUNCTION(nand),
+	FUNCTION(sata_led),
+	FUNCTION(lio),
+	FUNCTION(i2s),
+	FUNCTION(hda),
+	FUNCTION(uart2),
+	FUNCTION(uart1),
+	FUNCTION(camera),
+	FUNCTION(dvo1),
+	FUNCTION(dvo0),
+};
+
+static int loongson2_get_groups_count(struct pinctrl_dev *pcdev)
+{
+	return ARRAY_SIZE(loongson2_pmx_groups);
+}
+
+static const char *loongson2_get_group_name(struct pinctrl_dev *pcdev,
+					unsigned int selector)
+{
+	return loongson2_pmx_groups[selector].name;
+}
+
+static int loongson2_get_group_pins(struct pinctrl_dev *pcdev, unsigned int selector,
+			const unsigned int **pins, unsigned int *num_pins)
+{
+	*pins = loongson2_pmx_groups[selector].pins;
+	*num_pins = loongson2_pmx_groups[selector].num_pins;
+
+	return 0;
+}
+
+static void loongson2_pin_dbg_show(struct pinctrl_dev *pcdev, struct seq_file *s,
+			       unsigned int offset)
+{
+	seq_printf(s, " %s", dev_name(pcdev->dev));
+}
+
+static const struct pinctrl_ops loongson2_pctrl_ops = {
+	.get_groups_count	= loongson2_get_groups_count,
+	.get_group_name		= loongson2_get_group_name,
+	.get_group_pins		= loongson2_get_group_pins,
+	.dt_node_to_map		= pinconf_generic_dt_node_to_map_all,
+	.dt_free_map		= pinctrl_utils_free_map,
+	.pin_dbg_show		= loongson2_pin_dbg_show,
+};
+
+static int loongson2_pmx_set_mux(struct pinctrl_dev *pcdev, unsigned int func_num,
+			      unsigned int group_num)
+{
+	struct loongson2_pinctrl *pctrl = pinctrl_dev_get_drvdata(pcdev);
+	unsigned long reg = (unsigned long)pctrl->reg_base +
+				loongson2_pmx_groups[group_num].reg;
+	unsigned int mux_bit = loongson2_pmx_groups[group_num].bit;
+	unsigned int val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pctrl->lock, flags);
+	val = readl((void *)reg);
+	if (func_num == 0)
+		val &= ~(1<<mux_bit);
+	else
+		val |= (1<<mux_bit);
+	writel(val, (void *)reg);
+	spin_unlock_irqrestore(&pctrl->lock, flags);
+
+	return 0;
+}
+
+static int loongson2_pmx_get_funcs_count(struct pinctrl_dev *pcdev)
+{
+	return ARRAY_SIZE(loongson2_pmx_functions);
+}
+
+static const char *loongson2_pmx_get_func_name(struct pinctrl_dev *pcdev,
+				    unsigned int selector)
+{
+	return loongson2_pmx_functions[selector].name;
+}
+
+static int loongson2_pmx_get_groups(struct pinctrl_dev *pcdev,
+			 unsigned int selector,
+			 const char * const **groups,
+			 unsigned int * const num_groups)
+{
+	*groups = loongson2_pmx_functions[selector].groups;
+	*num_groups = loongson2_pmx_functions[selector].num_groups;
+
+	return 0;
+}
+
+static const struct pinmux_ops loongson2_pmx_ops = {
+	.set_mux = loongson2_pmx_set_mux,
+	.get_functions_count = loongson2_pmx_get_funcs_count,
+	.get_function_name = loongson2_pmx_get_func_name,
+	.get_function_groups = loongson2_pmx_get_groups,
+};
+
+static int loongson2_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct loongson2_pinctrl *pctrl;
+
+	pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
+	if (!pctrl)
+		return -ENOMEM;
+
+	pctrl->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pctrl->reg_base))
+		return dev_err_probe(pctrl->dev, PTR_ERR(pctrl->reg_base),
+				     "unable to map I/O memory");
+
+	spin_lock_init(&pctrl->lock);
+
+	pctrl->dev = dev;
+	pctrl->desc.name	= "pinctrl-loongson2";
+	pctrl->desc.owner	= THIS_MODULE;
+	pctrl->desc.pctlops	= &loongson2_pctrl_ops;
+	pctrl->desc.pmxops	= &loongson2_pmx_ops;
+	pctrl->desc.confops	= NULL;
+	pctrl->desc.pins	= loongson2_pctrl_pins;
+	pctrl->desc.npins	= ARRAY_SIZE(loongson2_pctrl_pins);
+
+	pctrl->pcdev = devm_pinctrl_register(pctrl->dev, &pctrl->desc, pctrl);
+	if (IS_ERR(pctrl->pcdev))
+		return dev_err_probe(pctrl->dev, PTR_ERR(pctrl->pcdev),
+				     "can't register pinctrl device");
+
+	return 0;
+}
+
+static const struct of_device_id loongson2_pinctrl_dt_match[] = {
+	{
+		.compatible = "loongson,ls2k-pinctrl",
+	},
+	{ },
+};
+
+static struct platform_driver loongson2_pinctrl_driver = {
+	.probe		= loongson2_pinctrl_probe,
+	.driver = {
+		.name	= "loongson2-pinctrl",
+		.of_match_table = loongson2_pinctrl_dt_match,
+	},
+};
+
+static int __init loongson2_pinctrl_init(void)
+{
+	return platform_driver_register(&loongson2_pinctrl_driver);
+}
+arch_initcall(loongson2_pinctrl_init);
+
+static void __exit loongson2_pinctrl_exit(void)
+{
+	platform_driver_unregister(&loongson2_pinctrl_driver);
+}
+module_exit(loongson2_pinctrl_exit);
-- 
2.20.1