PCI: mobiveil: Make some register updates more readable

To make some register updates more readable use a temporary
value to hold the register value and carry out the update.

Change the register update sequence to:

- Read out the original value from the target register
- Update the value
- Program the updated value back to the register

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>

diff --git a/drivers/pci/controller/pcie-mobiveil.c b/drivers/pci/controller/pcie-mobiveil.c
index 0767f1906fe69d18e1d2cf805770dd53fa1b08bd..906299b0d10ef2c4382c5c271a94d9ad9e8df151 100644 (file)
--- a/drivers/pci/controller/pcie-mobiveil.c
+++ b/drivers/pci/controller/pcie-mobiveil.c
@@ -299,6 +299,7 @@ static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
                                           unsigned int devfn, int where)
 {
        struct mobiveil_pcie *pcie = bus->sysdata;
+       u32 value;
 
        if (!mobiveil_pcie_valid_device(bus, devfn))
                return NULL;
@@ -313,10 +314,12 @@ static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
         * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
         * Relies on pci_lock serialization
         */
-       csr_writel(pcie, bus->number << PAB_BUS_SHIFT |
-                  PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
-                  PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT,
-                  PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
+       value = bus->number << PAB_BUS_SHIFT |
+               PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
+               PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT;
+
+       csr_writel(pcie, value, PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
+
        return pcie->config_axi_slave_base + where;
 }
 
@@ -463,19 +466,20 @@ static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
        }
 
        pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
-       csr_writel(pcie, pio_ctrl_val | (1 << PIO_ENABLE_SHIFT),
-                  PAB_PEX_PIO_CTRL);
-       amap_ctrl_dw = csr_readl(pcie, PAB_PEX_AMAP_CTRL(win_num));
-       amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
-       amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
+       pio_ctrl_val |= 1 << PIO_ENABLE_SHIFT;
+       csr_writel(pcie, pio_ctrl_val, PAB_PEX_PIO_CTRL);
 
-       csr_writel(pcie, amap_ctrl_dw | lower_32_bits(size64),
-                  PAB_PEX_AMAP_CTRL(win_num));
+       amap_ctrl_dw = csr_readl(pcie, PAB_PEX_AMAP_CTRL(win_num));
+       amap_ctrl_dw |= (type << AMAP_CTRL_TYPE_SHIFT) |
+                       (1 << AMAP_CTRL_EN_SHIFT) |
+                       lower_32_bits(size64);
+       csr_writel(pcie, amap_ctrl_dw, PAB_PEX_AMAP_CTRL(win_num));
 
        csr_writel(pcie, upper_32_bits(size64),
                   PAB_EXT_PEX_AMAP_SIZEN(win_num));
 
        csr_writel(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
+
        csr_writel(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
        csr_writel(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
 }
@@ -575,16 +579,16 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
         * Space
         */
        value = csr_readl(pcie, PCI_COMMAND);
-       csr_writel(pcie, value | PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
-                  PCI_COMMAND_MASTER, PCI_COMMAND);
+       value |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
+       csr_writel(pcie, value, PCI_COMMAND);
 
        /*
         * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
         * register
         */
        pab_ctrl = csr_readl(pcie, PAB_CTRL);
-       csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
-                  (1 << PEX_PIO_ENABLE_SHIFT), PAB_CTRL);
+       pab_ctrl |= (1 << AMBA_PIO_ENABLE_SHIFT) | (1 << PEX_PIO_ENABLE_SHIFT);
+       csr_writel(pcie, pab_ctrl, PAB_CTRL);
 
        csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
                   PAB_INTP_AMBA_MISC_ENB);
@@ -594,7 +598,8 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
         * PAB_AXI_PIO_CTRL Register
         */
        value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
-       csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
+       value |= APIO_EN_MASK;
+       csr_writel(pcie, value, PAB_AXI_PIO_CTRL);
 
        /*
         * we'll program one outbound window for config reads and
@@ -649,7 +654,8 @@ static void mobiveil_mask_intx_irq(struct irq_data *data)
        mask = 1 << ((data->hwirq + PAB_INTX_START) - 1);
        raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
        shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
-       csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
+       shifted_val &= ~mask;
+       csr_writel(pcie, shifted_val, PAB_INTP_AMBA_MISC_ENB);
        raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
 }
 
@@ -664,7 +670,8 @@ static void mobiveil_unmask_intx_irq(struct irq_data *data)
        mask = 1 << ((data->hwirq + PAB_INTX_START) - 1);
        raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
        shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
-       csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
+       shifted_val |= mask;
+       csr_writel(pcie, shifted_val, PAB_INTP_AMBA_MISC_ENB);
        raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
 }