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Message-ID: <1501985190.8058.20.camel@mtkswgap22>
Date: Sun, 6 Aug 2017 10:06:30 +0800
From: Ryder Lee <ryder.lee@...iatek.com>
To: <honghui.zhang@...iatek.com>
CC: <bhelgaas@...gle.com>, <robh@...enl.org>, <matthias.bgg@...il.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>, <linux-pci@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
<yingjoe.chen@...iatek.com>, <eddie.huang@...iatek.com>,
<hongkun.cao@...iatek.com>, <youlin.pei@...iatek.com>,
<yong.wu@...iatek.com>, <yt.shen@...iatek.com>,
<sean.wang@...iatek.com>, <xinping.qian@...iatek.com>
Subject: Re: [PATCH v3 5/6] PCI: mediatek: Add new generation controller
support
Hi Honghui,
If you plan to send next version, then I would suggest some minor
changes.
On Fri, 2017-08-04 at 20:06 +0800, honghui.zhang@...iatek.com wrote:
> +#define PCIE_CRSTB BIT(3)
> +#define PCIE_PERSTB BIT(8)
> +#define PCI_LINKDOWN_RST_EN GENMASK(15, 13)
PCIE_LINKDOWN_RST_EN
> +#define PCIE_LINK_STATUS_V2 0x804
> +#define PCIE_PORT_LINKUP_V2 BIT(10)
> +
> +
> +static int mtk_pcie_hw_rd_cfg(struct mtk_pcie_port *port, u32 bus, u32 devfn,
> + int where, int size, u32 *val)
> +{
> + int reg, shift = 8 * (where & 3);
int reg => u32
> + /* Write PCIe Configuration Transaction Header for cfgrd */
> + writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_RD_FMT),
> + port->base + PCIE_CFG_HEADER0);
> + writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
> + writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
> + port->base + PCIE_CFG_HEADER2);
> +
> + /* Trigger h/w to transmit Cfgrd TLP */
> + reg = readl(port->base + PCIE_APP_TLP_REQ);
> + writel(reg | APP_CFG_REQ, port->base + PCIE_APP_TLP_REQ);
> +
> + /* Check completion status */
> + if (mtk_pcie_check_cfg_cpld(port))
> + return PCIBIOS_SET_FAILED;
> +
> + /* Read cpld payload of Cfgrd */
> + *val = readl(port->base + PCIE_CFG_RDATA);
> +
> + switch (size) {
> + case 4:
> + break;
> + case 3:
> + *val = (*val >> shift) & 0xffffff;
> + break;
> + case 2:
> + *val = (*val >> shift) & 0xffff;
> + break;
> + case 1:
> + *val = (*val >> shift) & 0xff;
> + break;
> + default:
> + return PCIBIOS_BAD_REGISTER_NUMBER;
> + }
Do we really need case 3? I guess case 1, 2 or 4 should be enough.
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int mtk_pcie_hw_wr_cfg(struct mtk_pcie_port *port, u32 bus, u32 devfn,
> + int where, int size, u32 val)
> +{
> + /* Write PCIe Configuration Transaction Header for Cfgwr */
> + writel(CFG_HEADER_DW0(CFG_WRRD_TYPE_0, CFG_WR_FMT),
> + port->base + PCIE_CFG_HEADER0);
> + writel(CFG_HEADER_DW1(where, size), port->base + PCIE_CFG_HEADER1);
> + writel(CFG_HEADER_DW2(where, PCI_FUNC(devfn), PCI_SLOT(devfn), bus),
> + port->base + PCIE_CFG_HEADER2);
> +
> + /* Write cfgwr data */
> + val = val << 8 * (where & 3);
> + writel(val, port->base + PCIE_CFG_WDATA);
> +
> + /* Trigger h/w to transmit Cfgwr TLP */
> + val = readl(port->base + PCIE_APP_TLP_REQ);
> + val |= APP_CFG_REQ;
> + writel(val, port->base + PCIE_APP_TLP_REQ);
> +
> + /* Check completion status */
> + return mtk_pcie_check_cfg_cpld(port);
> +}
> +
> +static int mtk_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 *val)
> +{
> + struct mtk_pcie_port *port = NULL, *iter, *tmp;
> + struct mtk_pcie *pcie = bus->sysdata;
> + u32 bn = bus->number;
> + int ret;
> +
> + list_for_each_entry_safe(iter, tmp, &pcie->ports, list)
> + if (iter->index == PCI_SLOT(devfn)) {
> + port = iter;
> + break;
> + }
> +
> + if (!port) {
> + *val = ~0;
> + return PCIBIOS_DEVICE_NOT_FOUND;
> + }
list_for_each_entry(), since you don't really remove or free something.
I know you need to find port->base to write/read configuration space. I
think it's better to move this part to another function. You can take a
look at pci-mvebu.c mvebu_pcie_find_portmvebu().
> + ret = mtk_pcie_hw_rd_cfg(port, bn, devfn, where, size, val);
> + if (ret)
> + *val = ~0;
> +
> + return ret;
> +}
> +
> +static int mtk_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
> + int where, int size, u32 val)
> +{
> + struct mtk_pcie_port *port = NULL, *iter, *tmp;
> + struct mtk_pcie *pcie = bus->sysdata;
> + u32 bn = bus->number;
> +
> + list_for_each_entry_safe(iter, tmp, &pcie->ports, list)
> + if (iter->index == PCI_SLOT(devfn)) {
> + port = iter;
> + break;
> + }
> +
> + if (!port)
> + return PCIBIOS_DEVICE_NOT_FOUND;
Ditto.
> + return mtk_pcie_hw_wr_cfg(port, bn, devfn, where, size, val);
> +}
> +
> +static struct pci_ops mtk_pcie_ops_v2 = {
> + .read = mtk_pcie_config_read,
> + .write = mtk_pcie_config_write,
> +};
> +
> +static int mtk_pcie_startup_ports_v2(struct mtk_pcie_port *port)
> +{
> + struct mtk_pcie *pcie = port->pcie;
> + struct resource *mem = &pcie->mem;
> + u32 val;
> + size_t size;
> + int err;
> +
> + /* mt7622 platforms need to enable LTSSM and ASPM from PCIe subsys */
> + if (pcie->base) {
> + val = readl(pcie->base + PCIE_SYS_CFG_V2);
> + val |= PCIE_CSR_LTSSM_EN(port->index) |
> + PCIE_CSR_ASPM_L1_EN(port->index);
> + writel(val, pcie->base + PCIE_SYS_CFG_V2);
> + }
> +
> + /* Assert all reset signals */
> + writel(0, port->base + PCIE_RST_CTRL);
> +
> + /*
> + * Enable PCIe link down reset, if link status changed from link up to
> + * link down, this will reset MAC control registers and configuration
> + * space.
> + */
> + writel(PCI_LINKDOWN_RST_EN, port->base + PCIE_RST_CTRL);
> +
> + /* De-assert PHY, PE, PIPE, MAC and configuration reset */
> + val = readl(port->base + PCIE_RST_CTRL);
> + val |= PCIE_PHY_RSTB | PCIE_PERSTB | PCIE_PIPE_SRSTB |
> + PCIE_MAC_SRSTB | PCIE_CRSTB;
> + writel(val, port->base + PCIE_RST_CTRL);
> +
> + /* PCIe v2.0 need at least 100ms delay to train from Gen1 to Gen2 */
/* 100ms timeout value should be enough for Gen1/2 training */ for
consistency.
> + err = readl_poll_timeout(port->base + PCIE_LINK_STATUS_V2, val,
> + !!(val & PCIE_PORT_LINKUP_V2), 20,
> + 100 * USEC_PER_MSEC);
> + if (err)
> + return -ETIMEDOUT;
> +
> + /* Set INTx mask */
> + val = readl(port->base + PCIE_INT_MASK);
> + val &= ~INTX_MASK;
> + writel(val, port->base + PCIE_INT_MASK);
> +
> + /* Set AHB to PCIe translation windows */
> + size = mem->end - mem->start;
> + val = AHB2PCIE_BASEL(mem->start) | AHB2PCIE_SIZE(fls(size));
> + writel(val, port->base + PCIE_AHB_TRANS_BASE0_L);
> +
> + val = AHB2PCIE_BASEH(mem->start);
> + writel(val, port->base + PCIE_AHB_TRANS_BASE0_H);
> +
> + /* Set PCIe to AXI translation memory space.*/
> + val = fls(0xffffffff) | WIN_ENABLE;
> + writel(val, port->base + PCIE_AXI_WINDOW0);
> +
> + return 0;
> +}
Ryder
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