PCI: brcmstb: Do not assume that reg field starts at LSB

When setting a register field it was assumed that the field started at the
lsb of the register.  Although the masks do indeed start at the lsb, and
this will probably not change, it is prudent to use a method that makes no
assumption about the mask's placement in the register.

The uXXp_replace_bits() calls are used since they are already prevalent
in this driver.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>

Author: jamesequinlan

drivers/pci/controller/pcie-brcmstb.c

@@ -415,10 +415,10 @@ static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
 	u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
 	u32 lnkcap = readl(pcie->base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
 
-	lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
+	u32p_replace_bits(&lnkcap, gen, PCI_EXP_LNKCAP_SLS);
 	writel(lnkcap, pcie->base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
 
-	lnkctl2 = (lnkctl2 & ~0xf) | gen;
+	u16p_replace_bits(&lnkctl2, gen, PCI_EXP_LNKCTL2_TLS);
 	writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
 }