diff mbox

[v4,5/6] gpio: Add gpio driver support for ThunderX and OCTEON-TX

Message ID 1487206866-4011-6-git-send-email-david.daney@cavium.com
State New
Headers show

Commit Message

David Daney Feb. 16, 2017, 1:01 a.m. UTC
Cavium ThunderX and OCTEON-TX are arm64 based SoCs.  Add driver for
the on-chip GPIO pins.

Signed-off-by: David Daney <david.daney@cavium.com>
---
 drivers/gpio/Kconfig         |   8 +
 drivers/gpio/Makefile        |   1 +
 drivers/gpio/gpio-thunderx.c | 490 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 499 insertions(+)
 create mode 100644 drivers/gpio/gpio-thunderx.c

Comments

Linus Walleij Feb. 23, 2017, 1:46 p.m. UTC | #1
On Thu, Feb 16, 2017 at 2:01 AM, David Daney <david.daney@cavium.com> wrote:

> Cavium ThunderX and OCTEON-TX are arm64 based SoCs.  Add driver for
> the on-chip GPIO pins.
>
> Signed-off-by: David Daney <david.daney@cavium.com>

Hm due to an API change in the upstream kernel you will still have
to respin this driver, but I'm sure you will fix it in 5 minutes.

> +#define  GPIO_BIT_CFG_FIL_CNT_SHIFT    4
> +#define  GPIO_BIT_CFG_FIL_SEL_SHIFT    8
(...)
> +#define GLITCH_FILTER_400NS ((4ull << GPIO_BIT_CFG_FIL_SEL_SHIFT) | \
> +                            (9ull << GPIO_BIT_CFG_FIL_CNT_SHIFT))

This is what we call debounce in the API I think.

You can consider implementing it below in the .set_config()
function:

> +/*
> + * Weird, setting open-drain mode causes signal inversion.  Note this
> + * so we can compensate in the dir_out function.
> + */
> +static int thunderx_gpio_set_single_ended(struct gpio_chip *chip,
> +                                         unsigned int line,
> +                                         enum single_ended_mode mode)


This function is renamed .set_config() in v4.11.

This can also be used for setting debounce for the line, and
you proabably at some point want to add support for using the
more elaborate settings in the glitch filter for that.

> +       chip->label = KBUILD_MODNAME;
> +       chip->parent = dev;
> +       chip->owner = THIS_MODULE;
> +       chip->base = -1; /* System allocated */
> +       chip->can_sleep = false;
> +       chip->ngpio = ngpio;
> +       chip->direction_input = thunderx_gpio_dir_in;
> +       chip->get = thunderx_gpio_get;
> +       chip->direction_output = thunderx_gpio_dir_out;
> +       chip->set = thunderx_gpio_set;
> +       chip->set_multiple = thunderx_gpio_set_multiple;
> +       chip->set_single_ended = thunderx_gpio_set_single_ended;

So .set_config() is what we call this now. See converted drivers like
gpio-wcove.c etc for examples.

Hm no .get_direction() callback? I suggest to add that. It is useful
for the userspace ABI and more.

You could also add a ->names array with names for all the
lines if you like. This is also nice for userspace and for PCI-based
drivers that is the only way to insert line names for the chip.

Yours,
Linus Walleij
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diff mbox

Patch

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d5d3654..3da33ae 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -421,6 +421,14 @@  config GPIO_TS4800
 	help
 	  This driver support TS-4800 FPGA GPIO controllers.
 
+config GPIO_THUNDERX
+	tristate "Cavium ThunderX/OCTEON-TX GPIO"
+	depends on ARCH_THUNDER || (64BIT && COMPILE_TEST)
+	depends on PCI_MSI && IRQ_DOMAIN_HIERARCHY
+	help
+	  Say yes here to support the on-chip GPIO lines on the ThunderX
+	  and OCTEON-TX families of SoCs.
+
 config GPIO_TZ1090
 	bool "Toumaz Xenif TZ1090 GPIO support"
 	depends on SOC_TZ1090
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index a7676b8..c62bc72 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -108,6 +108,7 @@  obj-$(CONFIG_GPIO_SYSCON)	+= gpio-syscon.o
 obj-$(CONFIG_GPIO_TB10X)	+= gpio-tb10x.o
 obj-$(CONFIG_GPIO_TC3589X)	+= gpio-tc3589x.o
 obj-$(CONFIG_GPIO_TEGRA)	+= gpio-tegra.o
+obj-$(CONFIG_GPIO_THUNDERX)	+= gpio-thunderx.o
 obj-$(CONFIG_GPIO_TIMBERDALE)	+= gpio-timberdale.o
 obj-$(CONFIG_GPIO_PALMAS)	+= gpio-palmas.o
 obj-$(CONFIG_GPIO_TPIC2810)	+= gpio-tpic2810.o
diff --git a/drivers/gpio/gpio-thunderx.c b/drivers/gpio/gpio-thunderx.c
new file mode 100644
index 0000000..6afebc9
--- /dev/null
+++ b/drivers/gpio/gpio-thunderx.c
@@ -0,0 +1,490 @@ 
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2016, 2017 Cavium Inc.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+
+
+#define GPIO_RX_DAT	0x0
+#define GPIO_TX_SET	0x8
+#define GPIO_TX_CLR	0x10
+#define GPIO_CONST	0x90
+#define  GPIO_CONST_GPIOS_MASK 0xff
+#define GPIO_BIT_CFG	0x400
+#define  GPIO_BIT_CFG_TX_OE		BIT(0)
+#define  GPIO_BIT_CFG_PIN_XOR		BIT(1)
+#define  GPIO_BIT_CFG_INT_EN		BIT(2)
+#define  GPIO_BIT_CFG_INT_TYPE		BIT(3)
+#define  GPIO_BIT_CFG_FIL_CNT_SHIFT	4
+#define  GPIO_BIT_CFG_FIL_SEL_SHIFT	8
+#define  GPIO_BIT_CFG_TX_OD		BIT(12)
+#define  GPIO_BIT_CFG_PIN_SEL_MASK	GENMASK(25, 16)
+#define GPIO_INTR	0x800
+#define  GPIO_INTR_INTR			BIT(0)
+#define  GPIO_INTR_INTR_W1S		BIT(1)
+#define  GPIO_INTR_ENA_W1C		BIT(2)
+#define  GPIO_INTR_ENA_W1S		BIT(3)
+#define GPIO_2ND_BANK	0x1400
+
+#define GLITCH_FILTER_400NS ((4ull << GPIO_BIT_CFG_FIL_SEL_SHIFT) | \
+			     (9ull << GPIO_BIT_CFG_FIL_CNT_SHIFT))
+
+struct thunderx_gpio;
+
+struct thunderx_line {
+	struct thunderx_gpio	*txgpio;
+	unsigned int		line;
+};
+
+struct thunderx_gpio {
+	struct gpio_chip	chip;
+	u8 __iomem		*register_base;
+	struct irq_domain	*irqd;
+	struct msix_entry	*msix_entries;	/* per line MSI-X */
+	struct thunderx_line	*line_entries;	/* per line irq info */
+	raw_spinlock_t		lock;
+	unsigned long		invert_mask[2];
+	unsigned long		od_mask[2];
+	int			base_msi;
+};
+
+static unsigned int bit_cfg_reg(unsigned int line)
+{
+	return 8 * line + GPIO_BIT_CFG;
+}
+
+static unsigned int intr_reg(unsigned int line)
+{
+	return 8 * line + GPIO_INTR;
+}
+
+/*
+ * Check (and WARN) that the pin is available for GPIO.  We will not
+ * allow modification of the state of non-GPIO pins from this driver.
+ */
+static bool thunderx_gpio_is_gpio(struct thunderx_gpio *txgpio,
+				  unsigned int line)
+{
+	u64 bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
+	bool rv = (bit_cfg & GPIO_BIT_CFG_PIN_SEL_MASK) == 0;
+
+	WARN_RATELIMIT(!rv, "Pin %d not available for GPIO\n", line);
+
+	return rv;
+}
+
+static int thunderx_gpio_dir_in(struct gpio_chip *chip, unsigned int line)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+
+	if (!thunderx_gpio_is_gpio(txgpio, line))
+		return -EIO;
+
+	raw_spin_lock(&txgpio->lock);
+	clear_bit(line, txgpio->invert_mask);
+	clear_bit(line, txgpio->od_mask);
+	writeq(GLITCH_FILTER_400NS, txgpio->register_base + bit_cfg_reg(line));
+	raw_spin_unlock(&txgpio->lock);
+	return 0;
+}
+
+static void thunderx_gpio_set(struct gpio_chip *chip, unsigned int line,
+			      int value)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+	int bank = line / 64;
+	int bank_bit = line % 64;
+
+	void __iomem *reg = txgpio->register_base +
+		(bank * GPIO_2ND_BANK) + (value ? GPIO_TX_SET : GPIO_TX_CLR);
+
+	writeq(BIT_ULL(bank_bit), reg);
+}
+
+static int thunderx_gpio_dir_out(struct gpio_chip *chip, unsigned int line,
+				 int value)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+	u64 bit_cfg = GPIO_BIT_CFG_TX_OE;
+
+	if (!thunderx_gpio_is_gpio(txgpio, line))
+		return -EIO;
+
+	raw_spin_lock(&txgpio->lock);
+
+	thunderx_gpio_set(chip, line, value);
+
+	if (test_bit(line, txgpio->invert_mask))
+		bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
+
+	if (test_bit(line, txgpio->od_mask))
+		bit_cfg |= GPIO_BIT_CFG_TX_OD;
+
+	writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(line));
+
+	raw_spin_unlock(&txgpio->lock);
+	return 0;
+}
+
+/*
+ * Weird, setting open-drain mode causes signal inversion.  Note this
+ * so we can compensate in the dir_out function.
+ */
+static int thunderx_gpio_set_single_ended(struct gpio_chip *chip,
+					  unsigned int line,
+					  enum single_ended_mode mode)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+
+	if (mode == LINE_MODE_OPEN_SOURCE)
+		return -ENOTSUPP;
+
+	if (!thunderx_gpio_is_gpio(txgpio, line))
+		return -EIO;
+
+	raw_spin_lock(&txgpio->lock);
+	if (mode == LINE_MODE_OPEN_DRAIN) {
+		set_bit(line, txgpio->invert_mask);
+		set_bit(line, txgpio->od_mask);
+	} else {
+		clear_bit(line, txgpio->invert_mask);
+		clear_bit(line, txgpio->od_mask);
+	}
+	raw_spin_unlock(&txgpio->lock);
+
+	return 0;
+}
+
+static int thunderx_gpio_get(struct gpio_chip *chip, unsigned int line)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+	int bank = line / 64;
+	int bank_bit = line % 64;
+	u64 read_bits = readq(txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_RX_DAT);
+	u64 masked_bits = read_bits & BIT_ULL(bank_bit);
+
+	if (test_bit(line, txgpio->invert_mask))
+		return masked_bits == 0;
+	else
+		return masked_bits != 0;
+}
+
+static void thunderx_gpio_set_multiple(struct gpio_chip *chip,
+				       unsigned long *mask,
+				       unsigned long *bits)
+{
+	int bank;
+	u64 set_bits, clear_bits;
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+
+	for (bank = 0; bank <= chip->ngpio / 64; bank++) {
+		set_bits = bits[bank] & mask[bank];
+		clear_bits = ~bits[bank] & mask[bank];
+		writeq(set_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET);
+		writeq(clear_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_CLR);
+	}
+}
+
+static void thunderx_gpio_irq_ack(struct irq_data *data)
+{
+	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
+
+	writeq(GPIO_INTR_INTR,
+	       txline->txgpio->register_base + intr_reg(txline->line));
+}
+
+static void thunderx_gpio_irq_mask(struct irq_data *data)
+{
+	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
+
+	writeq(GPIO_INTR_ENA_W1C,
+	       txline->txgpio->register_base + intr_reg(txline->line));
+}
+
+static void thunderx_gpio_irq_mask_ack(struct irq_data *data)
+{
+	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
+
+	writeq(GPIO_INTR_ENA_W1C | GPIO_INTR_INTR,
+	       txline->txgpio->register_base + intr_reg(txline->line));
+}
+
+static void thunderx_gpio_irq_unmask(struct irq_data *data)
+{
+	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
+
+	writeq(GPIO_INTR_ENA_W1S,
+	       txline->txgpio->register_base + intr_reg(txline->line));
+}
+
+static int thunderx_gpio_irq_set_type(struct irq_data *data,
+				      unsigned int flow_type)
+{
+	struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
+	struct thunderx_gpio *txgpio = txline->txgpio;
+	u64 bit_cfg;
+
+	irqd_set_trigger_type(data, flow_type);
+
+	bit_cfg = GLITCH_FILTER_400NS | GPIO_BIT_CFG_INT_EN;
+
+	if (flow_type & IRQ_TYPE_EDGE_BOTH) {
+		irq_set_handler_locked(data, handle_fasteoi_edge_irq);
+		bit_cfg |= GPIO_BIT_CFG_INT_TYPE;
+	} else {
+		irq_set_handler_locked(data, handle_fasteoi_level_irq);
+	}
+
+	raw_spin_lock(&txgpio->lock);
+	if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_LEVEL_LOW)) {
+		bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
+		set_bit(txline->line, txgpio->invert_mask);
+	} else {
+		clear_bit(txline->line, txgpio->invert_mask);
+	}
+	clear_bit(txline->line, txgpio->od_mask);
+	writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(txline->line));
+	raw_spin_unlock(&txgpio->lock);
+
+	return IRQ_SET_MASK_OK;
+}
+
+static void thunderx_gpio_irq_enable(struct irq_data *data)
+{
+	irq_chip_enable_parent(data);
+	thunderx_gpio_irq_unmask(data);
+}
+
+static void thunderx_gpio_irq_disable(struct irq_data *data)
+{
+	thunderx_gpio_irq_mask(data);
+	irq_chip_disable_parent(data);
+}
+
+/*
+ * Interrupts are chained from underlying MSI-X vectors.  We have
+ * these irq_chip functions to be able to handle level triggering
+ * semantics and other acknowledgment tasks associated with the GPIO
+ * mechanism.
+ */
+static struct irq_chip thunderx_gpio_irq_chip = {
+	.name			= "GPIO",
+	.irq_enable		= thunderx_gpio_irq_enable,
+	.irq_disable		= thunderx_gpio_irq_disable,
+	.irq_ack		= thunderx_gpio_irq_ack,
+	.irq_mask		= thunderx_gpio_irq_mask,
+	.irq_mask_ack		= thunderx_gpio_irq_mask_ack,
+	.irq_unmask		= thunderx_gpio_irq_unmask,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+	.irq_set_type		= thunderx_gpio_irq_set_type,
+
+	.flags			= IRQCHIP_SET_TYPE_MASKED
+};
+
+static int thunderx_gpio_irq_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
+{
+	irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);
+	return 0;
+}
+
+static int thunderx_gpio_irq_translate(struct irq_domain *d,
+				       struct irq_fwspec *fwspec,
+				       irq_hw_number_t *hwirq,
+				       unsigned int *type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+	*hwirq = fwspec->param[0];
+	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+
+static int thunderx_gpio_irq_alloc(struct irq_domain *d, unsigned int virq,
+				   unsigned int nr_irqs, void *arg)
+{
+	struct thunderx_line *txline = arg;
+
+	return irq_domain_set_hwirq_and_chip(d, virq, txline->line,
+					     &thunderx_gpio_irq_chip, txline);
+}
+
+static const struct irq_domain_ops thunderx_gpio_irqd_ops = {
+	.map		= thunderx_gpio_irq_map,
+	.alloc		= thunderx_gpio_irq_alloc,
+	.translate	= thunderx_gpio_irq_translate
+};
+
+static int thunderx_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
+
+	return irq_find_mapping(txgpio->irqd, offset);
+}
+
+static int thunderx_gpio_probe(struct pci_dev *pdev,
+			       const struct pci_device_id *id)
+{
+	void __iomem * const *tbl;
+	struct device *dev = &pdev->dev;
+	struct thunderx_gpio *txgpio;
+	struct gpio_chip *chip;
+	int ngpio, i;
+	int err = 0;
+
+	txgpio = devm_kzalloc(dev, sizeof(*txgpio), GFP_KERNEL);
+	if (!txgpio)
+		return -ENOMEM;
+
+	raw_spin_lock_init(&txgpio->lock);
+	chip = &txgpio->chip;
+
+	pci_set_drvdata(pdev, txgpio);
+
+	err = pcim_enable_device(pdev);
+	if (err) {
+		dev_err(dev, "Failed to enable PCI device: err %d\n", err);
+		goto out;
+	}
+
+	err = pcim_iomap_regions(pdev, 1 << 0, KBUILD_MODNAME);
+	if (err) {
+		dev_err(dev, "Failed to iomap PCI device: err %d\n", err);
+		goto out;
+	}
+
+	tbl = pcim_iomap_table(pdev);
+	txgpio->register_base = tbl[0];
+	if (!txgpio->register_base) {
+		dev_err(dev, "Cannot map PCI resource\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	if (pdev->subsystem_device == 0xa10a) {
+		/* CN88XX has no GPIO_CONST register*/
+		ngpio = 50;
+		txgpio->base_msi = 48;
+	} else {
+		u64 c = readq(txgpio->register_base + GPIO_CONST);
+
+		ngpio = c & GPIO_CONST_GPIOS_MASK;
+		txgpio->base_msi = (c >> 8) & 0xff;
+	}
+
+	txgpio->msix_entries = devm_kzalloc(dev,
+					  sizeof(struct msix_entry) * ngpio,
+					  GFP_KERNEL);
+	if (!txgpio->msix_entries) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	txgpio->line_entries = devm_kzalloc(dev,
+					    sizeof(struct thunderx_line) * ngpio,
+					    GFP_KERNEL);
+	if (!txgpio->line_entries) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0; i < ngpio; i++) {
+		txgpio->msix_entries[i].entry = txgpio->base_msi + (2 * i);
+		txgpio->line_entries[i].line = i;
+		txgpio->line_entries[i].txgpio = txgpio;
+	}
+
+
+	/* Enable all MSI-X for interrupts on all possible lines. */
+	err = pci_enable_msix(pdev, txgpio->msix_entries, ngpio);
+	if (err < 0)
+		goto out;
+
+	/*
+	 * Push GPIO specific irqdomain on hierarchy created as a side
+	 * effect of the pci_enable_msix()
+	 */
+	txgpio->irqd = irq_domain_create_hierarchy(irq_get_irq_data(txgpio->msix_entries[0].vector)->domain,
+						   0, 0, of_node_to_fwnode(dev->of_node),
+						   &thunderx_gpio_irqd_ops, txgpio);
+	if (!txgpio->irqd)
+		goto out;
+
+	/* Push on irq_data and the domain for each line. */
+	for (i = 0; i < ngpio; i++) {
+		err = irq_domain_push_irq(txgpio->irqd,
+					  txgpio->msix_entries[i].vector,
+					  &txgpio->line_entries[i]);
+		if (err < 0)
+			dev_err(dev, "irq_domain_push_irq: %d\n", err);
+	}
+
+	chip->label = KBUILD_MODNAME;
+	chip->parent = dev;
+	chip->owner = THIS_MODULE;
+	chip->base = -1; /* System allocated */
+	chip->can_sleep = false;
+	chip->ngpio = ngpio;
+	chip->direction_input = thunderx_gpio_dir_in;
+	chip->get = thunderx_gpio_get;
+	chip->direction_output = thunderx_gpio_dir_out;
+	chip->set = thunderx_gpio_set;
+	chip->set_multiple = thunderx_gpio_set_multiple;
+	chip->set_single_ended = thunderx_gpio_set_single_ended;
+	chip->to_irq = thunderx_gpio_to_irq;
+	err = devm_gpiochip_add_data(dev, chip, txgpio);
+	if (err)
+		goto out;
+
+	dev_info(dev, "ThunderX GPIO: %d lines with base %d.\n",
+		 ngpio, chip->base);
+	return 0;
+out:
+	pci_set_drvdata(pdev, NULL);
+	return err;
+}
+
+static void thunderx_gpio_remove(struct pci_dev *pdev)
+{
+	int i;
+	struct thunderx_gpio *txgpio = pci_get_drvdata(pdev);
+
+	for (i = 0; i < txgpio->chip.ngpio; i++)
+		irq_domain_pop_irq(txgpio->irqd,
+				   txgpio->msix_entries[i].vector);
+
+	irq_domain_remove(txgpio->irqd);
+
+	pci_set_drvdata(pdev, NULL);
+}
+
+static const struct pci_device_id thunderx_gpio_id_table[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xA00A) },
+	{ 0, }	/* end of table */
+};
+
+MODULE_DEVICE_TABLE(pci, thunderx_gpio_id_table);
+
+static struct pci_driver thunderx_gpio_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = thunderx_gpio_id_table,
+	.probe = thunderx_gpio_probe,
+	.remove = thunderx_gpio_remove,
+};
+
+module_pci_driver(thunderx_gpio_driver);
+
+MODULE_DESCRIPTION("Cavium Inc. ThunderX/OCTEON-TX GPIO Driver");
+MODULE_LICENSE("GPL");