[PATCH v5 2/5] PCI: designware: refactor MSI code to work with v3.65 dw hardware

[Murali Karicheri]

Keystone PCI controller is based on v3.65 version of the DW
PCI h/w that implements MSI controller registers in application
space compared to the newer version. This requires updates to
the DW core API to support the PCI controller driver based on
this old DW hardware. Add msi_irq_set()/clear() API functions to
allow Set/Clear MSI IRQ enable bit in the application register.
Also the old h/w uses MSI_IRQ register in application register
space to raise MSI IRQ to the RC from EP. Current code uses the
standard mechanism as per PCI spec. So add another API get_msi_data()
to get the address of this register so that common code can be
re-used on old h/w.

Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
Acked-by: Mohit Kumar <mohit.kumar at st.com>
Acked-by: Jingoo Han <jg1.han at samsung.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar at ti.com>

CC: Russell King <linux at arm.linux.org.uk>
CC: Grant Likely <grant.likely at linaro.org>
CC: Rob Herring <robh+dt at kernel.org>
CC: Bjorn Helgaas <bhelgaas at google.com>
CC: Pratyush Anand <pratyush.anand at st.com>
CC: Richard Zhu <r65037 at freescale.com>
CC: Kishon Vijay Abraham I <kishon at ti.com>
CC: Marek Vasut <marex at denx.de>
CC: Arnd Bergmann <arnd at arndb.de>
CC: Pawel Moll <pawel.moll at arm.com>
CC: Mark Rutland <mark.rutland at arm.com>
CC: Ian Campbell <ijc+devicetree at hellion.org.uk>
CC: Kumar Gala <galak at codeaurora.org>
CC: Randy Dunlap <rdunlap at infradead.org>
CC: Grant Likely <grant.likely at linaro.org>
---
 drivers/pci/host/pcie-designware.c |   50 ++++++++++++++++++++++++++----------
 drivers/pci/host/pcie-designware.h |    3 +++
 2 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index d8f3af7..905941c 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -217,27 +217,47 @@ static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0)
 	return 0;
 }
 
+static void dw_pcie_msi_clear_irq(struct pcie_port *pp, int irq)
+{
+	unsigned int res, bit, val;
+
+	res = (irq / 32) * 12;
+	bit = irq % 32;
+	dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
+	val &= ~(1 << bit);
+	dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+}
+
 static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
 			    unsigned int nvec, unsigned int pos)
 {
-	unsigned int i, res, bit, val;
+	unsigned int i;
 
 	for (i = 0; i < nvec; i++) {
 		irq_set_msi_desc_off(irq_base, i, NULL);
 		clear_bit(pos + i, pp->msi_irq_in_use);
 		/* Disable corresponding interrupt on MSI controller */
-		res = ((pos + i) / 32) * 12;
-		bit = (pos + i) % 32;
-		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
-		val &= ~(1 << bit);
-		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+		if (pp->ops->msi_clear_irq)
+			pp->ops->msi_clear_irq(pp, pos + i);
+		else
+			dw_pcie_msi_clear_irq(pp, pos + i);
 	}
 }
 
+static void dw_pcie_msi_set_irq(struct pcie_port *pp, int irq)
+{
+	unsigned int res, bit, val;
+
+	res = (irq / 32) * 12;
+	bit = irq % 32;
+	dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
+	val |= 1 << bit;
+	dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+}
+
 static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
 {
-	int res, bit, irq, pos0, pos1, i;
-	u32 val;
+	int irq, pos0, pos1, i;
 	struct pcie_port *pp = sys_to_pcie(desc->dev->bus->sysdata);
 
 	if (!pp) {
@@ -281,11 +301,10 @@ static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
 		}
 		set_bit(pos0 + i, pp->msi_irq_in_use);
 		/*Enable corresponding interrupt in MSI interrupt controller */
-		res = ((pos0 + i) / 32) * 12;
-		bit = (pos0 + i) % 32;
-		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val);
-		val |= 1 << bit;
-		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val);
+		if (pp->ops->msi_set_irq)
+			pp->ops->msi_set_irq(pp, pos0 + i);
+		else
+			dw_pcie_msi_set_irq(pp, pos0 + i);
 	}
 
 	*pos = pos0;
@@ -353,7 +372,10 @@ static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
 	 */
 	desc->msi_attrib.multiple = msgvec;
 
-	msg.address_lo = virt_to_phys((void *)pp->msi_data);
+	if (pp->ops->get_msi_data)
+		msg.address_lo = pp->ops->get_msi_data(pp);
+	else
+		msg.address_lo = virt_to_phys((void *)pp->msi_data);
 	msg.address_hi = 0x0;
 	msg.data = pos;
 	write_msi_msg(irq, &msg);
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index 8121901..387f69e 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -67,6 +67,9 @@ struct pcie_host_ops {
 			unsigned int devfn, int where, int size, u32 val);
 	int (*link_up)(struct pcie_port *pp);
 	void (*host_init)(struct pcie_port *pp);
+	void (*msi_set_irq)(struct pcie_port *pp, int irq);
+	void (*msi_clear_irq)(struct pcie_port *pp, int irq);
+	u32 (*get_msi_data)(struct pcie_port *pp);
 };
 
 int dw_pcie_cfg_read(void __iomem *addr, int where, int size, u32 *val);
-- 
1.7.9.5