diff mbox series

[net-next,v9,6/9] net: txgbe: Support GPIO to SFP socket

Message ID 20230524091722.522118-7-jiawenwu@trustnetic.com
State Superseded
Headers show
Series TXGBE PHYLINK support | expand

Commit Message

Jiawen Wu May 24, 2023, 9:17 a.m. UTC
Register GPIO chip and handle GPIO IRQ for SFP socket.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
 drivers/net/ethernet/wangxun/Kconfig          |   2 +
 drivers/net/ethernet/wangxun/libwx/wx_lib.c   |   3 +-
 drivers/net/ethernet/wangxun/libwx/wx_type.h  |   3 +
 .../net/ethernet/wangxun/txgbe/txgbe_main.c   |  20 +-
 .../net/ethernet/wangxun/txgbe/txgbe_phy.c    | 248 ++++++++++++++++++
 .../net/ethernet/wangxun/txgbe/txgbe_type.h   |  23 ++
 6 files changed, 280 insertions(+), 19 deletions(-)

Comments

Andrew Lunn May 24, 2023, 12:51 p.m. UTC | #1
> +static void txgbe_toggle_trigger(struct gpio_chip *gc, unsigned int offset)
> +{
> +	struct wx *wx = gpiochip_get_data(gc);
> +	u32 pol, val;
> +
> +	pol = rd32(wx, WX_GPIO_POLARITY);
> +	val = rd32(wx, WX_GPIO_EXT);
> +
> +	if (val & BIT(offset))
> +		pol &= ~BIT(offset);
> +	else
> +		pol |= BIT(offset);
> +
> +	wr32(wx, WX_GPIO_POLARITY, pol);
> +}

So you look at the current state of the GPIO and set the polarity to
trigger an interrupt when it changes.

This is not race free. And if it does race, at best you loose an
interrupt. The worst is your hardware locks up because that interrupt
was missed and it cannot continue until some action is taken.

Is there any other GPIO driver doing this?

I think you would be better indicating you don't support
IRQ_TYPE_EDGE_BOTH.

	Andrew
Russell King (Oracle) May 24, 2023, 1:07 p.m. UTC | #2
On Wed, May 24, 2023 at 02:51:25PM +0200, Andrew Lunn wrote:
> > +static void txgbe_toggle_trigger(struct gpio_chip *gc, unsigned int offset)
> > +{
> > +	struct wx *wx = gpiochip_get_data(gc);
> > +	u32 pol, val;
> > +
> > +	pol = rd32(wx, WX_GPIO_POLARITY);
> > +	val = rd32(wx, WX_GPIO_EXT);
> > +
> > +	if (val & BIT(offset))
> > +		pol &= ~BIT(offset);
> > +	else
> > +		pol |= BIT(offset);
> > +
> > +	wr32(wx, WX_GPIO_POLARITY, pol);
> > +}
> 
> So you look at the current state of the GPIO and set the polarity to
> trigger an interrupt when it changes.
> 
> This is not race free. And if it does race, at best you loose an
> interrupt. The worst is your hardware locks up because that interrupt
> was missed and it cannot continue until some action is taken.
> 
> Is there any other GPIO driver doing this?
> 
> I think you would be better indicating you don't support
> IRQ_TYPE_EDGE_BOTH.

... which will make the whole point of having interrupt support for this
driver moot, and the SFP code will then poll the GPIOs which will
probably more reliably detect changes.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/wangxun/Kconfig b/drivers/net/ethernet/wangxun/Kconfig
index 90812d76181d..73f4492928c0 100644
--- a/drivers/net/ethernet/wangxun/Kconfig
+++ b/drivers/net/ethernet/wangxun/Kconfig
@@ -41,6 +41,8 @@  config TXGBE
 	tristate "Wangxun(R) 10GbE PCI Express adapters support"
 	depends on PCI
 	select I2C_DESIGNWARE_PLATFORM
+	select GPIOLIB_IRQCHIP
+	select GPIOLIB
 	select REGMAP
 	select COMMON_CLK
 	select LIBWX
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_lib.c b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
index 1e8d8b7b0c62..590215303d45 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_lib.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
@@ -1348,7 +1348,8 @@  void wx_free_irq(struct wx *wx)
 		free_irq(entry->vector, q_vector);
 	}
 
-	free_irq(wx->msix_entries[vector].vector, wx);
+	if (wx->mac.type == wx_mac_em)
+		free_irq(wx->msix_entries[vector].vector, wx);
 }
 EXPORT_SYMBOL(wx_free_irq);
 
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_type.h b/drivers/net/ethernet/wangxun/libwx/wx_type.h
index f59066d7375c..297c389fa890 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_type.h
+++ b/drivers/net/ethernet/wangxun/libwx/wx_type.h
@@ -79,7 +79,9 @@ 
 #define WX_GPIO_INTMASK              0x14834
 #define WX_GPIO_INTTYPE_LEVEL        0x14838
 #define WX_GPIO_POLARITY             0x1483C
+#define WX_GPIO_INTSTATUS            0x14844
 #define WX_GPIO_EOI                  0x1484C
+#define WX_GPIO_EXT                  0x14850
 
 /*********************** Transmit DMA registers **************************/
 /* transmit global control */
@@ -643,6 +645,7 @@  struct wx {
 	bool wol_enabled;
 	bool ncsi_enabled;
 	bool gpio_ctrl;
+	raw_spinlock_t gpio_lock;
 
 	/* Tx fast path data */
 	int num_tx_queues;
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
index e10296abf5b4..ded04e9e136f 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
@@ -82,6 +82,8 @@  static int txgbe_enumerate_functions(struct wx *wx)
  **/
 static void txgbe_irq_enable(struct wx *wx, bool queues)
 {
+	wr32(wx, WX_PX_MISC_IEN, TXGBE_PX_MISC_IEN_MASK);
+
 	/* unmask interrupt */
 	wx_intr_enable(wx, TXGBE_INTR_MISC(wx));
 	if (queues)
@@ -129,17 +131,6 @@  static irqreturn_t txgbe_intr(int __always_unused irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t txgbe_msix_other(int __always_unused irq, void *data)
-{
-	struct wx *wx = data;
-
-	/* re-enable the original interrupt state */
-	if (netif_running(wx->netdev))
-		txgbe_irq_enable(wx, false);
-
-	return IRQ_HANDLED;
-}
-
 /**
  * txgbe_request_msix_irqs - Initialize MSI-X interrupts
  * @wx: board private structure
@@ -171,13 +162,6 @@  static int txgbe_request_msix_irqs(struct wx *wx)
 		}
 	}
 
-	err = request_irq(wx->msix_entries[vector].vector,
-			  txgbe_msix_other, 0, netdev->name, wx);
-	if (err) {
-		wx_err(wx, "request_irq for msix_other failed: %d\n", err);
-		goto free_queue_irqs;
-	}
-
 	return 0;
 
 free_queue_irqs:
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c
index 3da5f5538f34..6aba22a4fc5e 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c
@@ -2,6 +2,8 @@ 
 /* Copyright (c) 2015 - 2023 Beijing WangXun Technology Co., Ltd. */
 
 #include <linux/platform_device.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/driver.h>
 #include <linux/gpio/property.h>
 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
@@ -10,6 +12,7 @@ 
 #include <linux/pci.h>
 
 #include "../libwx/wx_type.h"
+#include "../libwx/wx_hw.h"
 #include "txgbe_type.h"
 #include "txgbe_phy.h"
 
@@ -74,6 +77,245 @@  static int txgbe_swnodes_register(struct txgbe *txgbe)
 	return software_node_register_node_group(nodes->group);
 }
 
+static int txgbe_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct wx *wx = gpiochip_get_data(chip);
+	int val;
+
+	val = rd32m(wx, WX_GPIO_EXT, BIT(offset));
+
+	return !!(val & BIT(offset));
+}
+
+static int txgbe_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+	struct wx *wx = gpiochip_get_data(chip);
+	u32 val;
+
+	val = rd32(wx, WX_GPIO_DDR);
+	if (BIT(offset) & val)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int txgbe_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
+{
+	struct wx *wx = gpiochip_get_data(chip);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+	wr32m(wx, WX_GPIO_DDR, BIT(offset), 0);
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+
+	return 0;
+}
+
+static int txgbe_gpio_direction_out(struct gpio_chip *chip, unsigned int offset,
+				    int val)
+{
+	struct wx *wx = gpiochip_get_data(chip);
+	unsigned long flags;
+	u32 set;
+
+	set = val ? BIT(offset) : 0;
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+	wr32m(wx, WX_GPIO_DR, BIT(offset), set);
+	wr32m(wx, WX_GPIO_DDR, BIT(offset), BIT(offset));
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+
+	return 0;
+}
+
+static void txgbe_gpio_irq_ack(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	struct wx *wx = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+	wr32(wx, WX_GPIO_EOI, BIT(hwirq));
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+}
+
+static void txgbe_gpio_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	struct wx *wx = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	gpiochip_disable_irq(gc, hwirq);
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+	wr32m(wx, WX_GPIO_INTMASK, BIT(hwirq), BIT(hwirq));
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+}
+
+static void txgbe_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	struct wx *wx = gpiochip_get_data(gc);
+	unsigned long flags;
+
+	gpiochip_enable_irq(gc, hwirq);
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+	wr32m(wx, WX_GPIO_INTMASK, BIT(hwirq), 0);
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+}
+
+static void txgbe_toggle_trigger(struct gpio_chip *gc, unsigned int offset)
+{
+	struct wx *wx = gpiochip_get_data(gc);
+	u32 pol, val;
+
+	pol = rd32(wx, WX_GPIO_POLARITY);
+	val = rd32(wx, WX_GPIO_EXT);
+
+	if (val & BIT(offset))
+		pol &= ~BIT(offset);
+	else
+		pol |= BIT(offset);
+
+	wr32(wx, WX_GPIO_POLARITY, pol);
+}
+
+static int txgbe_gpio_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+	struct wx *wx = gpiochip_get_data(gc);
+	u32 level, polarity, mask;
+	unsigned long flags;
+
+	mask = BIT(hwirq);
+
+	if (type & IRQ_TYPE_LEVEL_MASK) {
+		level = 0;
+		irq_set_handler_locked(d, handle_level_irq);
+	} else {
+		level = mask;
+		irq_set_handler_locked(d, handle_edge_irq);
+	}
+
+	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
+		polarity = mask;
+	else
+		polarity = 0;
+
+	raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+
+	wr32m(wx, WX_GPIO_INTEN, mask, mask);
+	wr32m(wx, WX_GPIO_INTTYPE_LEVEL, mask, level);
+	if (type == IRQ_TYPE_EDGE_BOTH)
+		txgbe_toggle_trigger(gc, hwirq);
+	else
+		wr32m(wx, WX_GPIO_POLARITY, mask, polarity);
+
+	raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+
+	return 0;
+}
+
+static const struct irq_chip txgbe_gpio_irq_chip = {
+	.name = "txgbe_gpio_irq",
+	.irq_ack = txgbe_gpio_irq_ack,
+	.irq_mask = txgbe_gpio_irq_mask,
+	.irq_unmask = txgbe_gpio_irq_unmask,
+	.irq_set_type = txgbe_gpio_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static void txgbe_irq_handler(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct wx *wx = irq_desc_get_handler_data(desc);
+	struct txgbe *txgbe = wx->priv;
+	irq_hw_number_t hwirq;
+	unsigned long gpioirq;
+	struct gpio_chip *gc;
+	unsigned long flags;
+
+	chained_irq_enter(chip, desc);
+
+	gpioirq = rd32(wx, WX_GPIO_INTSTATUS);
+
+	gc = txgbe->gpio;
+	for_each_set_bit(hwirq, &gpioirq, gc->ngpio) {
+		int gpio = irq_find_mapping(gc->irq.domain, hwirq);
+		u32 irq_type = irq_get_trigger_type(gpio);
+
+		generic_handle_domain_irq(gc->irq.domain, hwirq);
+
+		if ((irq_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
+			raw_spin_lock_irqsave(&wx->gpio_lock, flags);
+			txgbe_toggle_trigger(gc, hwirq);
+			raw_spin_unlock_irqrestore(&wx->gpio_lock, flags);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+
+	/* unmask interrupt */
+	wx_intr_enable(wx, TXGBE_INTR_MISC(wx));
+}
+
+static int txgbe_gpio_init(struct txgbe *txgbe)
+{
+	struct gpio_irq_chip *girq;
+	struct gpio_chip *gc;
+	struct device *dev;
+	struct wx *wx;
+	int ret;
+
+	wx = txgbe->wx;
+	dev = &wx->pdev->dev;
+
+	raw_spin_lock_init(&wx->gpio_lock);
+
+	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+	if (!gc)
+		return -ENOMEM;
+
+	gc->label = devm_kasprintf(dev, GFP_KERNEL, "txgbe_gpio-%x",
+				   (wx->pdev->bus->number << 8) | wx->pdev->devfn);
+	gc->base = -1;
+	gc->ngpio = 6;
+	gc->owner = THIS_MODULE;
+	gc->parent = dev;
+	gc->fwnode = software_node_fwnode(txgbe->nodes.group[SWNODE_GPIO]);
+	gc->get = txgbe_gpio_get;
+	gc->get_direction = txgbe_gpio_get_direction;
+	gc->direction_input = txgbe_gpio_direction_in;
+	gc->direction_output = txgbe_gpio_direction_out;
+
+	girq = &gc->irq;
+	gpio_irq_chip_set_chip(girq, &txgbe_gpio_irq_chip);
+	girq->parent_handler = txgbe_irq_handler;
+	girq->parent_handler_data = wx;
+	girq->num_parents = 1;
+	girq->parents = devm_kcalloc(dev, girq->num_parents,
+				     sizeof(*girq->parents), GFP_KERNEL);
+	if (!girq->parents)
+		return -ENOMEM;
+	girq->parents[0] = wx->msix_entries[wx->num_q_vectors].vector;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_bad_irq;
+
+	ret = devm_gpiochip_add_data(dev, gc, wx);
+	if (ret)
+		return ret;
+
+	txgbe->gpio = gc;
+
+	return 0;
+}
+
 static int txgbe_clock_register(struct txgbe *txgbe)
 {
 	struct pci_dev *pdev = txgbe->wx->pdev;
@@ -187,6 +429,12 @@  int txgbe_init_phy(struct txgbe *txgbe)
 		return ret;
 	}
 
+	ret = txgbe_gpio_init(txgbe);
+	if (ret) {
+		wx_err(txgbe->wx, "failed to init gpio\n");
+		goto err_unregister_swnode;
+	}
+
 	ret = txgbe_clock_register(txgbe);
 	if (ret) {
 		wx_err(txgbe->wx, "failed to register clock: %d\n", ret);
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h b/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
index fc91e0fc37a6..6c903e4517c7 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_type.h
@@ -55,6 +55,28 @@ 
 #define TXGBE_TS_CTL                            0x10300
 #define TXGBE_TS_CTL_EVAL_MD                    BIT(31)
 
+/* GPIO register bit */
+#define TXGBE_GPIOBIT_0                         BIT(0) /* I:tx fault */
+#define TXGBE_GPIOBIT_1                         BIT(1) /* O:tx disabled */
+#define TXGBE_GPIOBIT_2                         BIT(2) /* I:sfp module absent */
+#define TXGBE_GPIOBIT_3                         BIT(3) /* I:rx signal lost */
+#define TXGBE_GPIOBIT_4                         BIT(4) /* O:rate select, 1G(0) 10G(1) */
+#define TXGBE_GPIOBIT_5                         BIT(5) /* O:rate select, 1G(0) 10G(1) */
+
+/* Extended Interrupt Enable Set */
+#define TXGBE_PX_MISC_ETH_LKDN                  BIT(8)
+#define TXGBE_PX_MISC_DEV_RST                   BIT(10)
+#define TXGBE_PX_MISC_ETH_EVENT                 BIT(17)
+#define TXGBE_PX_MISC_ETH_LK                    BIT(18)
+#define TXGBE_PX_MISC_ETH_AN                    BIT(19)
+#define TXGBE_PX_MISC_INT_ERR                   BIT(20)
+#define TXGBE_PX_MISC_GPIO                      BIT(26)
+#define TXGBE_PX_MISC_IEN_MASK                            \
+	(TXGBE_PX_MISC_ETH_LKDN | TXGBE_PX_MISC_DEV_RST | \
+	 TXGBE_PX_MISC_ETH_EVENT | TXGBE_PX_MISC_ETH_LK | \
+	 TXGBE_PX_MISC_ETH_AN | TXGBE_PX_MISC_INT_ERR |   \
+	 TXGBE_PX_MISC_GPIO)
+
 /* I2C registers */
 #define TXGBE_I2C_BASE                          0x14900
 
@@ -153,6 +175,7 @@  struct txgbe {
 	struct platform_device *i2c_dev;
 	struct clk_lookup *clock;
 	struct clk *clk;
+	struct gpio_chip *gpio;
 };
 
 #endif /* _TXGBE_TYPE_H_ */