Commit d785ed94 authored by Jinjian Song's avatar Jinjian Song Committed by David S. Miller
Browse files

net: wwan: t7xx: PCIe reset rescan 

WWAN device is programmed to boot in normal mode or fastboot mode,
when triggering a device reset through ACPI call or fastboot switch
command. Maintain state machine synchronization and reprobe logic
after a device reset.

The PCIe device reset triggered by several ways.
E.g.:
 - fastboot: echo "fastboot_switching" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - reset: echo "reset" > /sys/bus/pci/devices/${bdf}/t7xx_mode.
 - IRQ: PCIe device request driver to reset itself by an interrupt request.

Use pci_reset_function() as a generic way to reset device, save and
restore the PCIe configuration before and after reset device to ensure
the reprobe process.

Suggestion from Bjorn:
Link: https://lore.kernel.org/all/20230127133034.GA1364550@bhelgaas/



Signed-off-by: default avatarJinjian Song <jinjian.song@fibocom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4d36b2b1

drivers/net/wwan/t7xx/t7xx_modem_ops.c

+40 −7
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ 


#define RGU_RESET_DELAY_MS	10

#define PORT_RESET_DELAY_MS	2000

#define FASTBOOT_RESET_DELAY_MS	2000

#define EX_HS_TIMEOUT_MS	5000

#define EX_HS_POLL_DELAY_MS	10
@@ -167,19 +168,52 @@ static int t7xx_acpi_reset(struct t7xx_pci_dev *t7xx_dev, char *fn_name) 
	}



	kfree(buffer.pointer);

#else

	struct device *dev = &t7xx_dev->pdev->dev;

	int ret;



	ret = pci_reset_function(t7xx_dev->pdev);

	if (ret) {

		dev_err(dev, "Failed to reset device, error:%d\n", ret);

		return ret;

	}

#endif

	return 0;

}



int t7xx_acpi_fldr_func(struct t7xx_pci_dev *t7xx_dev)

static void t7xx_host_event_notify(struct t7xx_pci_dev *t7xx_dev, unsigned int event_id)

{

	return t7xx_acpi_reset(t7xx_dev, "_RST");

	u32 value;



	value = ioread32(IREG_BASE(t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);

	value &= ~HOST_EVENT_MASK;

	value |= FIELD_PREP(HOST_EVENT_MASK, event_id);

	iowrite32(value, IREG_BASE(t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);

}



int t7xx_acpi_pldr_func(struct t7xx_pci_dev *t7xx_dev)

int t7xx_reset_device(struct t7xx_pci_dev *t7xx_dev, enum reset_type type)

{

	return t7xx_acpi_reset(t7xx_dev, "MRST._RST");

	int ret = 0;



	pci_save_state(t7xx_dev->pdev);

	t7xx_pci_reprobe_early(t7xx_dev);

	t7xx_mode_update(t7xx_dev, T7XX_RESET);



	if (type == FLDR) {

		ret = t7xx_acpi_reset(t7xx_dev, "_RST");

	} else if (type == PLDR) {

		ret = t7xx_acpi_reset(t7xx_dev, "MRST._RST");

	} else if (type == FASTBOOT) {

		t7xx_host_event_notify(t7xx_dev, FASTBOOT_DL_NOTIFY);

		t7xx_mhccif_h2d_swint_trigger(t7xx_dev, H2D_CH_DEVICE_RESET);

		msleep(FASTBOOT_RESET_DELAY_MS);

	}



	pci_restore_state(t7xx_dev->pdev);

	if (ret)

		return ret;



	return t7xx_pci_reprobe(t7xx_dev, true);

}



static void t7xx_reset_device_via_pmic(struct t7xx_pci_dev *t7xx_dev)
@@ -188,16 +222,15 @@ static void t7xx_reset_device_via_pmic(struct t7xx_pci_dev *t7xx_dev) 


	val = ioread32(IREG_BASE(t7xx_dev) + T7XX_PCIE_MISC_DEV_STATUS);

	if (val & MISC_RESET_TYPE_PLDR)

		t7xx_acpi_reset(t7xx_dev, "MRST._RST");

		t7xx_reset_device(t7xx_dev, PLDR);

	else if (val & MISC_RESET_TYPE_FLDR)

		t7xx_acpi_fldr_func(t7xx_dev);

		t7xx_reset_device(t7xx_dev, FLDR);

}



static irqreturn_t t7xx_rgu_isr_thread(int irq, void *data)

{

	struct t7xx_pci_dev *t7xx_dev = data;



	t7xx_mode_update(t7xx_dev, T7XX_RESET);

	msleep(RGU_RESET_DELAY_MS);

	t7xx_reset_device_via_pmic(t7xx_dev);

	return IRQ_HANDLED;

drivers/net/wwan/t7xx/t7xx_modem_ops.h

+7 −2
Original line number Diff line number Diff line
@@ -78,14 +78,19 @@ struct t7xx_modem { 
	spinlock_t			exp_lock; /* Protects exception events */

};



enum reset_type {

	FLDR,

	PLDR,

	FASTBOOT,

};



void t7xx_md_exception_handshake(struct t7xx_modem *md);

void t7xx_md_event_notify(struct t7xx_modem *md, enum md_event_id evt_id);

int t7xx_md_reset(struct t7xx_pci_dev *t7xx_dev);

int t7xx_md_init(struct t7xx_pci_dev *t7xx_dev);

void t7xx_md_exit(struct t7xx_pci_dev *t7xx_dev);

void t7xx_clear_rgu_irq(struct t7xx_pci_dev *t7xx_dev);

int t7xx_acpi_fldr_func(struct t7xx_pci_dev *t7xx_dev);

int t7xx_acpi_pldr_func(struct t7xx_pci_dev *t7xx_dev);

int t7xx_reset_device(struct t7xx_pci_dev *t7xx_dev, enum reset_type type);

int t7xx_pci_mhccif_isr(struct t7xx_pci_dev *t7xx_dev);



#endif	/* __T7XX_MODEM_OPS_H__ */

drivers/net/wwan/t7xx/t7xx_pci.c

+43 −10
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ static ssize_t t7xx_mode_store(struct device *dev, 
{

	struct t7xx_pci_dev *t7xx_dev;

	struct pci_dev *pdev;

	enum t7xx_mode mode;

	int index = 0;



	pdev = to_pci_dev(dev);
@@ -76,12 +77,22 @@ static ssize_t t7xx_mode_store(struct device *dev, 
	if (!t7xx_dev)

		return -ENODEV;



	mode = READ_ONCE(t7xx_dev->mode);



	index = sysfs_match_string(t7xx_mode_names, buf);

	if (index == mode)

		return -EBUSY;



	if (index == T7XX_FASTBOOT_SWITCHING) {

		if (mode == T7XX_FASTBOOT_DOWNLOAD)

			return count;



		WRITE_ONCE(t7xx_dev->mode, T7XX_FASTBOOT_SWITCHING);

		pm_runtime_resume(dev);

		t7xx_reset_device(t7xx_dev, FASTBOOT);

	} else if (index == T7XX_RESET) {

		WRITE_ONCE(t7xx_dev->mode, T7XX_RESET);

		t7xx_acpi_pldr_func(t7xx_dev);

		pm_runtime_resume(dev);

		t7xx_reset_device(t7xx_dev, PLDR);

	}



	return count;
@@ -446,7 +457,7 @@ static int t7xx_pcie_reinit(struct t7xx_pci_dev *t7xx_dev, bool is_d3) 


	if (is_d3) {

		t7xx_mhccif_init(t7xx_dev);

		return t7xx_pci_pm_reinit(t7xx_dev);

		t7xx_pci_pm_reinit(t7xx_dev);

	}



	return 0;
@@ -481,6 +492,33 @@ static int t7xx_send_fsm_command(struct t7xx_pci_dev *t7xx_dev, u32 event) 
	return ret;

}



int t7xx_pci_reprobe_early(struct t7xx_pci_dev *t7xx_dev)

{

	enum t7xx_mode mode = READ_ONCE(t7xx_dev->mode);

	int ret;



	if (mode == T7XX_FASTBOOT_DOWNLOAD)

		pm_runtime_put_noidle(&t7xx_dev->pdev->dev);



	ret = t7xx_send_fsm_command(t7xx_dev, FSM_CMD_STOP);

	if (ret)

		return ret;



	return 0;

}



int t7xx_pci_reprobe(struct t7xx_pci_dev *t7xx_dev, bool boot)

{

	int ret;



	ret = t7xx_pcie_reinit(t7xx_dev, boot);

	if (ret)

		return ret;



	t7xx_clear_rgu_irq(t7xx_dev);

	return t7xx_send_fsm_command(t7xx_dev, FSM_CMD_START);

}



static int __t7xx_pci_pm_resume(struct pci_dev *pdev, bool state_check)

{

	struct t7xx_pci_dev *t7xx_dev;
@@ -507,16 +545,11 @@ static int __t7xx_pci_pm_resume(struct pci_dev *pdev, bool state_check) 
		if (prev_state == PM_RESUME_REG_STATE_L3 ||

		    (prev_state == PM_RESUME_REG_STATE_INIT &&

		     atr_reg_val == ATR_SRC_ADDR_INVALID)) {

			ret = t7xx_send_fsm_command(t7xx_dev, FSM_CMD_STOP);

			if (ret)

				return ret;



			ret = t7xx_pcie_reinit(t7xx_dev, true);

			ret = t7xx_pci_reprobe_early(t7xx_dev);

			if (ret)

				return ret;



			t7xx_clear_rgu_irq(t7xx_dev);

			return t7xx_send_fsm_command(t7xx_dev, FSM_CMD_START);

			return t7xx_pci_reprobe(t7xx_dev, true);

		}



		if (prev_state == PM_RESUME_REG_STATE_EXP ||

drivers/net/wwan/t7xx/t7xx_pci.h

+3 −0
Original line number Diff line number Diff line
@@ -133,4 +133,7 @@ int t7xx_pci_pm_entity_unregister(struct t7xx_pci_dev *t7xx_dev, struct md_pm_en 
void t7xx_pci_pm_init_late(struct t7xx_pci_dev *t7xx_dev);

void t7xx_pci_pm_exp_detected(struct t7xx_pci_dev *t7xx_dev);

void t7xx_mode_update(struct t7xx_pci_dev *t7xx_dev, enum t7xx_mode mode);

int t7xx_pci_reprobe(struct t7xx_pci_dev *t7xx_dev, bool boot);

int t7xx_pci_reprobe_early(struct t7xx_pci_dev *t7xx_dev);



#endif /* __T7XX_PCI_H__ */

drivers/net/wwan/t7xx/t7xx_port_proxy.c

+0 −1
Original line number Diff line number Diff line
@@ -553,7 +553,6 @@ static int t7xx_proxy_alloc(struct t7xx_modem *md) 


	md->port_prox = port_prox;

	port_prox->dev = dev;

	t7xx_port_proxy_set_cfg(md, PORT_CFG_ID_EARLY);



	return 0;

}