[PATCH v2 4/6] PCI: brcmstb: add Broadcom STB PCIe host controller driver

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: andrew.murray@arm.com, maz@kernel.org,
	linux-kernel@vger.kernel.org,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Eric Anholt <eric@anholt.net>, Stefan Wahren <wahrenst@gmx.net>,
	Florian Fainelli <f.fainelli@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com
Cc: james.quinlan@broadcom.com, mbrugger@suse.com,
	phil@raspberrypi.org, jeremy.linton@arm.com,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-pci@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 4/6] PCI: brcmstb: add Broadcom STB PCIe host controller driver
Date: Tue, 12 Nov 2019 16:59:23 +0100	[thread overview]
Message-ID: <20191112155926.16476-5-nsaenzjulienne@suse.de> (raw)
In-Reply-To: <20191112155926.16476-1-nsaenzjulienne@suse.de>

From: Jim Quinlan <james.quinlan@broadcom.com>

This commit adds the basic Broadcom STB PCIe controller.  Missing is the
ability to process MSI. This functionality is added in a subsequent
commit.

The PCIe block contains an MDIO interface.  This is a local interface
only accessible by the PCIe controller.  It cannot be used or shared
by any other HW.  As such, the small amount of code for this
controller is included in this driver as there is little upside to put
it elsewhere.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v1:
  - Fix Kconfig
  - Remove pci domain check
  - Remove all MSI related code
  - Remove supend/resume code
  - Simplify link state wait routine
  - Prefix all functions
  - Use of_device_get_match_data()
  - Use devm_clk_get_optional()
  - Get rid of irq variable
  - Use STB all over the driver
  - Fix license mismatch
  - Remove unused register definitions
  - Small cleanups, spell errors

NOTE: I decided to remove the suspend/resume routines for now. The
      RPi4 doesn't need it, and we where having issues with the
      specifics of the resume function on devices we yet don't support.
      We'll deal with this in the future.

This is based on Jim's original submission[1] but adapted and tailored
specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
the rest of the brcmstb family will soon follow once we get support for
multiple dma-ranges in dma/direct.

[1] https://patchwork.kernel.org/patch/10605959/

 drivers/pci/controller/Kconfig        |   8 +
 drivers/pci/controller/Makefile       |   1 +
 drivers/pci/controller/pcie-brcmstb.c | 855 ++++++++++++++++++++++++++
 3 files changed, 864 insertions(+)
 create mode 100644 drivers/pci/controller/pcie-brcmstb.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index f5de9119e8d3..486d4d570233 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -281,6 +281,14 @@ config VMD
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmd.
 
+config PCIE_BRCMSTB
+	bool "Broadcom Brcmstb PCIe host controller"
+	depends on ARCH_BCM2835 || COMPILE_TEST
+	depends on OF
+	help
+	  Say Y here to enable PCIe host controller support for
+	  Broadcom STB based SoCs, like the Raspberry Pi 4.
+
 config PCI_HYPERV_INTERFACE
 	tristate "Hyper-V PCI Interface"
 	depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index a2a22c9d91af..3fc0b0cf5b5b 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
 obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
 obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
 obj-$(CONFIG_VMD) += vmd.o
+obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
 obj-y				+= dwc/
 
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
new file mode 100644
index 000000000000..8d81c5ab5979
--- /dev/null
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -0,0 +1,855 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2009 - 2019 Broadcom */
+
+#include <linux/clk.h>
+#include <linux/compiler.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/printk.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "../pci.h"
+
+/* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
+#define BRCM_PCIE_CAP_REGS				0x00ac
+
+/*
+ * Broadcom STB PCIe Register Offsets. The names are from the chip's RDB and we
+ * use them here so that a script can correlate this code and the RDB to
+ * prevent discrepancies.
+ */
+#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1		0x0188
+#define PCIE_RC_CFG_PRIV1_ID_VAL3			0x043c
+#define PCIE_RC_DL_MDIO_ADDR				0x1100
+#define PCIE_RC_DL_MDIO_WR_DATA				0x1104
+#define PCIE_RC_DL_MDIO_RD_DATA				0x1108
+#define PCIE_MISC_MISC_CTRL				0x4008
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO		0x400c
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI		0x4010
+#define PCIE_MISC_RC_BAR1_CONFIG_LO			0x402c
+#define PCIE_MISC_RC_BAR2_CONFIG_LO			0x4034
+#define PCIE_MISC_RC_BAR2_CONFIG_HI			0x4038
+#define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
+#define PCIE_MISC_PCIE_CTRL				0x4064
+#define PCIE_MISC_PCIE_STATUS				0x4068
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT	0x4070
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI		0x4080
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI		0x4084
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG			0x4204
+#define PCIE_INTR2_CPU_BASE				0x4300
+
+/*
+ * Broadcom STB PCIe Register Field shift and mask info. The names are from the
+ * chip's RDB and we use them here so that a script can correlate this code and
+ * the RDB to prevent discrepancies.
+ */
+#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK	0xc
+#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_SHIFT	0x2
+#define PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK		0xffffff
+#define PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_SHIFT		0x0
+#define PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK			0x1000
+#define PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_SHIFT			0xc
+#define PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK		0x2000
+#define PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_SHIFT		0xd
+#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK			0x300000
+#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_SHIFT		0x14
+#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK			0xf8000000
+#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_SHIFT			0x1b
+#define PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK			0x1f
+#define PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_SHIFT			0x0
+#define PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK			0x1f
+#define PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_SHIFT			0x0
+#define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK			0x1f
+#define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_SHIFT			0x0
+#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK		0x1
+#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_SHIFT		0x0
+#define PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK			0x80
+#define PCIE_MISC_PCIE_STATUS_PCIE_PORT_SHIFT			0x7
+#define PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK		0x20
+#define PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_SHIFT		0x5
+#define PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK		0x10
+#define PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_SHIFT		0x4
+#define PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK		0x40
+#define PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_SHIFT		0x6
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK	0xfff00000
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_SHIFT	0x14
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK	0xfff0
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_SHIFT	0x4
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS	0xc
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK		0xff
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_SHIFT	0x0
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK	0xff
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_SHIFT	0x0
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK	0x2
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_SHIFT 0x1
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK		0x08000000
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_SHIFT	0x1b
+#define PCIE_RGR1_SW_INIT_1_PERST_MASK				0x1
+#define PCIE_RGR1_SW_INIT_1_PERST_SHIFT				0x0
+
+#define BRCM_NUM_PCIE_OUT_WINS		0x4
+
+#define BURST_SIZE_128			0
+
+/* Offsets from PCIE_INTR2_CPU_BASE */
+#define STATUS                          0x0
+#define CLR				0x8
+#define MASK_SET			0x10
+#define MASK_CLR			0x14
+
+#define PCIE_BUSNUM_SHIFT		20
+#define PCIE_SLOT_SHIFT			15
+#define PCIE_FUNC_SHIFT			12
+
+#if defined(__BIG_ENDIAN)
+#define	DATA_ENDIAN			2	/* PCIe->DDR inbound traffic */
+#define MMIO_ENDIAN			2	/* CPU->PCIe outbound traffic */
+#else
+#define	DATA_ENDIAN			0
+#define MMIO_ENDIAN			0
+#endif
+
+#define MDIO_PORT0			0x0
+#define MDIO_DATA_MASK			0x7fffffff
+#define MDIO_DATA_SHIFT			0x0
+#define MDIO_PORT_MASK			0xf0000
+#define MDIO_PORT_SHIFT			0x16
+#define MDIO_REGAD_MASK			0xffff
+#define MDIO_REGAD_SHIFT		0x0
+#define MDIO_CMD_MASK			0xfff00000
+#define MDIO_CMD_SHIFT			0x14
+#define MDIO_CMD_READ			0x1
+#define MDIO_CMD_WRITE			0x0
+#define MDIO_DATA_DONE_MASK		0x80000000
+#define MDIO_RD_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
+#define MDIO_WT_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
+#define SSC_REGS_ADDR			0x1100
+#define SET_ADDR_OFFSET			0x1f
+#define SSC_CNTL_OFFSET			0x2
+#define SSC_CNTL_OVRD_EN_MASK		0x8000
+#define SSC_CNTL_OVRD_EN_SHIFT		0xf
+#define SSC_CNTL_OVRD_VAL_MASK		0x4000
+#define SSC_CNTL_OVRD_VAL_SHIFT		0xe
+#define SSC_STATUS_OFFSET		0x1
+#define SSC_STATUS_SSC_MASK		0x400
+#define SSC_STATUS_SSC_SHIFT		0xa
+#define SSC_STATUS_PLL_LOCK_MASK	0x800
+#define SSC_STATUS_PLL_LOCK_SHIFT	0xb
+
+#define BRCM_PCIE_IDX_ADDR(pcie)	\
+	((pcie)->reg_offsets[EXT_CFG_INDEX])
+#define BRCM_PCIE_DATA_ADDR(pcie)	\
+	((pcie)->reg_offsets[EXT_CFG_DATA])
+#define BRCM_PCIE_RGR1_SW_INIT_1(pcie) \
+	((pcie)->reg_offsets[RGR1_SW_INIT_1])
+
+enum {
+	RGR1_SW_INIT_1,
+	EXT_CFG_INDEX,
+	EXT_CFG_DATA,
+};
+
+enum {
+	RGR1_SW_INIT_1_INIT_MASK,
+	RGR1_SW_INIT_1_INIT_SHIFT,
+	RGR1_SW_INIT_1_PERST_MASK,
+	RGR1_SW_INIT_1_PERST_SHIFT,
+};
+
+enum pcie_type {
+	BCM2711,
+};
+
+struct brcm_window {
+	dma_addr_t pcie_addr;
+	phys_addr_t cpu_addr;
+	dma_addr_t size;
+};
+
+/* Internal PCIe Host Controller Information.*/
+struct brcm_pcie {
+	struct device		*dev;
+	void __iomem		*base;
+	struct clk		*clk;
+	struct pci_bus		*root_bus;
+	struct device_node	*np;
+	bool			ssc;
+	int			gen;
+	struct brcm_window	out_wins[BRCM_NUM_PCIE_OUT_WINS];
+	const int		*reg_offsets;
+	const int		*reg_field_info;
+	enum pcie_type		type;
+};
+
+struct pcie_cfg_data {
+	const int		*reg_field_info;
+	const int		*offsets;
+	const enum pcie_type	type;
+};
+
+static const int pcie_reg_field_info[] = {
+	[RGR1_SW_INIT_1_INIT_MASK] = 0x2,
+	[RGR1_SW_INIT_1_INIT_SHIFT] = 0x1,
+};
+
+static const int pcie_offset_bcm2711[] = {
+	[RGR1_SW_INIT_1] = 0x9210,
+	[EXT_CFG_INDEX]  = 0x9000,
+	[EXT_CFG_DATA]   = 0x8000,
+};
+
+static const struct pcie_cfg_data bcm2711_cfg = {
+	.reg_field_info	= pcie_reg_field_info,
+	.offsets	= pcie_offset_bcm2711,
+	.type		= BCM2711,
+};
+
+static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
+					int where);
+
+static struct pci_ops brcm_pcie_ops = {
+	.map_bus = brcm_pcie_map_conf,
+	.read = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+#define bcm_readl(a)		readl(a)
+#define bcm_writel(d, a)	writel(d, a)
+#define bcm_readw(a)		readw(a)
+#define bcm_writew(d, a)	writew(d, a)
+
+/* These macros extract/insert fields to host controller's register set. */
+#define RD_FLD(base, reg, field) \
+	brcm_pcie_rd_fld((base) + reg, reg##_##field##_MASK, \
+			 reg##_##field##_SHIFT)
+#define WR_FLD(base, reg, field, val) \
+	brcm_pcie_wr_fld((base) + reg, reg##_##field##_MASK, \
+		    reg##_##field##_SHIFT, val)
+#define WR_FLD_RB(base, reg, field, val) \
+	brcm_pcie_wr_fld_rb((base) + reg, reg##_##field##_MASK, \
+		reg##_##field##_SHIFT, val)
+#define WR_FLD_WITH_OFFSET(base, off, reg, field, val) \
+	brcm_pcie_wr_fld((base) + reg + (off), reg##_##field##_MASK, \
+	       reg##_##field##_SHIFT, val)
+#define EXTRACT_FIELD(val, reg, field) \
+	(((val) & reg##_##field##_MASK) >> reg##_##field##_SHIFT)
+#define INSERT_FIELD(val, reg, field, field_val) \
+	(((val) & ~reg##_##field##_MASK) | \
+	 (reg##_##field##_MASK & (field_val << reg##_##field##_SHIFT)))
+
+static u32 brcm_pcie_rd_fld(void __iomem *p, u32 mask, int shift)
+{
+	return (bcm_readl(p) & mask) >> shift;
+}
+
+static void brcm_pcie_wr_fld(void __iomem *p, u32 mask, int shift, u32 val)
+{
+	u32 reg = bcm_readl(p);
+
+	reg = (reg & ~mask) | ((val << shift) & mask);
+	bcm_writel(reg, p);
+}
+
+static void brcm_pcie_wr_fld_rb(void __iomem *p, u32 mask, int shift, u32 val)
+{
+	brcm_pcie_wr_fld(p, mask, shift, val);
+	(void)bcm_readl(p);
+}
+
+/*
+ * This is to convert the size of the inbound "BAR" region to the
+ * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
+ */
+int brcm_pcie_encode_ibar_size(u64 size)
+{
+	int log2_in = ilog2(size);
+
+	if (log2_in >= 12 && log2_in <= 15)
+		/* Covers 4KB to 32KB (inclusive) */
+		return (log2_in - 12) + 0x1c;
+	else if (log2_in >= 16 && log2_in <= 35)
+		/* Covers 64KB to 32GB, (inclusive) */
+		return log2_in - 15;
+	/* Something is awry so disable */
+	return 0;
+}
+
+static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
+{
+	u32 pkt = 0;
+
+	pkt |= (port << MDIO_PORT_SHIFT) & MDIO_PORT_MASK;
+	pkt |= (regad << MDIO_REGAD_SHIFT) & MDIO_REGAD_MASK;
+	pkt |= (cmd << MDIO_CMD_SHIFT) & MDIO_CMD_MASK;
+
+	return pkt;
+}
+
+/* negative return value indicates error */
+static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad)
+{
+	int tries;
+	u32 data;
+
+	bcm_writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
+		   base + PCIE_RC_DL_MDIO_ADDR);
+	bcm_readl(base + PCIE_RC_DL_MDIO_ADDR);
+
+	data = bcm_readl(base + PCIE_RC_DL_MDIO_RD_DATA);
+	for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
+		udelay(10);
+		data = bcm_readl(base + PCIE_RC_DL_MDIO_RD_DATA);
+	}
+
+	return MDIO_RD_DONE(data)
+		? (data & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT
+		: -EIO;
+}
+
+/* negative return value indicates error */
+static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
+				u8 regad, u16 wrdata)
+{
+	int tries;
+	u32 data;
+
+	bcm_writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
+		   base + PCIE_RC_DL_MDIO_ADDR);
+	bcm_readl(base + PCIE_RC_DL_MDIO_ADDR);
+	bcm_writel(MDIO_DATA_DONE_MASK | wrdata,
+		   base + PCIE_RC_DL_MDIO_WR_DATA);
+
+	data = bcm_readl(base + PCIE_RC_DL_MDIO_WR_DATA);
+	for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
+		udelay(10);
+		data = bcm_readl(base + PCIE_RC_DL_MDIO_WR_DATA);
+	}
+
+	return MDIO_WT_DONE(data) ? 0 : -EIO;
+}
+
+/*
+ * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
+ * return value indicates error.
+ */
+static int brcm_pcie_set_ssc(void __iomem *base)
+{
+	int pll, ssc;
+	u16 wrdata;
+	int tmp;
+
+	tmp = brcm_pcie_mdio_write(base, MDIO_PORT0, SET_ADDR_OFFSET,
+				   SSC_REGS_ADDR);
+	if (tmp < 0)
+		return tmp;
+
+	tmp = brcm_pcie_mdio_read(base, MDIO_PORT0, SSC_CNTL_OFFSET);
+	if (tmp < 0)
+		return tmp;
+
+	wrdata = INSERT_FIELD(tmp, SSC_CNTL_OVRD, EN, 1);
+	wrdata = INSERT_FIELD(wrdata, SSC_CNTL_OVRD, VAL, 1);
+	tmp = brcm_pcie_mdio_write(base, MDIO_PORT0, SSC_CNTL_OFFSET, wrdata);
+	if (tmp < 0)
+		return tmp;
+
+	usleep_range(1000, 2000);
+	tmp = brcm_pcie_mdio_read(base, MDIO_PORT0, SSC_STATUS_OFFSET);
+	if (tmp < 0)
+		return tmp;
+
+	ssc = EXTRACT_FIELD(tmp, SSC_STATUS, SSC);
+	pll = EXTRACT_FIELD(tmp, SSC_STATUS, PLL_LOCK);
+
+	return (ssc && pll) ? 0 : -EIO;
+}
+
+/* Limits operation to a specific generation (1, 2, or 3) */
+static void brcm_pcie_set_gen(void __iomem *base, int gen)
+{
+	u32 lnkcap = bcm_readl(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
+	u16 lnkctl2 = bcm_readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
+
+	lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
+	bcm_writel(lnkcap, base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
+
+	lnkctl2 = (lnkctl2 & ~0xf) | gen;
+	bcm_writew(lnkctl2, base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
+}
+
+static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
+				       unsigned int win, phys_addr_t cpu_addr,
+				       dma_addr_t  pcie_addr, dma_addr_t size)
+{
+	phys_addr_t cpu_addr_mb, limit_addr_mb;
+	void __iomem *base = pcie->base;
+	u32 tmp;
+
+	/* Set the base of the pcie_addr window */
+	bcm_writel(lower_32_bits(pcie_addr) + MMIO_ENDIAN,
+		   base + PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + (win * 8));
+	bcm_writel(upper_32_bits(pcie_addr),
+		   base + PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + (win * 8));
+
+	cpu_addr_mb = cpu_addr >> 20;
+	limit_addr_mb = (cpu_addr + size - 1) >> 20;
+
+	/* Write the addr base low register */
+	WR_FLD_WITH_OFFSET(base, (win * 4),
+			   PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT,
+			   BASE, cpu_addr_mb);
+	/* Write the addr limit low register */
+	WR_FLD_WITH_OFFSET(base, (win * 4),
+			   PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT,
+			   LIMIT, limit_addr_mb);
+
+	/* Write the cpu addr high register */
+	tmp = (u32)(cpu_addr_mb >>
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS);
+	WR_FLD_WITH_OFFSET(base, (win * 8),
+			   PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI,
+			   BASE, tmp);
+	/* Write the cpu limit high register */
+	tmp = (u32)(limit_addr_mb >>
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS);
+	WR_FLD_WITH_OFFSET(base, (win * 8),
+			   PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI,
+			   LIMIT, tmp);
+}
+
+/* Configuration space read/write support */
+static int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
+{
+	return ((PCI_SLOT(devfn) & 0x1f) << PCIE_SLOT_SHIFT)
+		| ((PCI_FUNC(devfn) & 0x07) << PCIE_FUNC_SHIFT)
+		| (busnr << PCIE_BUSNUM_SHIFT)
+		| (reg & ~3);
+}
+
+/* The controller is capable of serving in both RC and EP roles */
+static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	u32 val = bcm_readl(base + PCIE_MISC_PCIE_STATUS);
+
+	return !!EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_PORT);
+}
+
+static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	u32 val = bcm_readl(base + PCIE_MISC_PCIE_STATUS);
+	u32 dla = EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_DL_ACTIVE);
+	u32 plu = EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_PHYLINKUP);
+
+	return  (dla && plu) ? true : false;
+}
+
+static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
+					int where)
+{
+	struct brcm_pcie *pcie = bus->sysdata;
+	void __iomem *base = pcie->base;
+	int idx;
+
+	/* Accesses to the RC go right to the RC registers if slot==0 */
+	if (pci_is_root_bus(bus))
+		return PCI_SLOT(devfn) ? NULL : base + where;
+
+	/* For devices, write to the config space index register */
+	idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
+	bcm_writel(idx, pcie->base + BRCM_PCIE_IDX_ADDR(pcie));
+	return base + BRCM_PCIE_DATA_ADDR(pcie) + where;
+}
+
+static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie,
+						unsigned int val)
+{
+	unsigned int shift = pcie->reg_field_info[RGR1_SW_INIT_1_INIT_SHIFT];
+	u32 mask =  pcie->reg_field_info[RGR1_SW_INIT_1_INIT_MASK];
+
+	brcm_pcie_wr_fld_rb(pcie->base + BRCM_PCIE_RGR1_SW_INIT_1(pcie),
+		       mask, shift, val);
+}
+
+static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie,
+				       unsigned int val)
+{
+	brcm_pcie_wr_fld_rb(pcie->base + BRCM_PCIE_RGR1_SW_INIT_1(pcie),
+		  PCIE_RGR1_SW_INIT_1_PERST_MASK,
+		  PCIE_RGR1_SW_INIT_1_PERST_SHIFT, val);
+}
+
+static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
+							u64 *rc_bar2_size,
+							u64 *rc_bar2_offset)
+{
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+	struct device *dev = pcie->dev;
+	struct resource_entry *entry;
+	u64 total_mem_size = 0;
+
+	*rc_bar2_offset = -1;
+
+	resource_list_for_each_entry(entry, &bridge->dma_ranges) {
+		/*
+		 * We're promised the RC will provide a contiguous view of
+		 * memory to downstream devices. We can then infer the
+		 * rc_bar2_offset from the lower available dma-range offset.
+		 */
+		if (entry->offset < *rc_bar2_offset)
+			*rc_bar2_offset = entry->offset;
+
+		total_mem_size += entry->res->end - entry->res->start + 1;
+	}
+
+	*rc_bar2_size = roundup_pow_of_two64(total_mem_size);
+
+	/*
+	 * Validate the results:
+	 *
+	 * The PCIe host controller by design must set the inbound viewport to
+	 * be a contiguous arrangement of all of the system's memory.  In
+	 * addition, its size mut be a power of two.  To further complicate
+	 * matters, the viewport must start on a pcie-address that is aligned
+	 * on a multiple of its size.  If a portion of the viewport does not
+	 * represent system memory -- e.g. 3GB of memory requires a 4GB
+	 * viewport -- we can map the outbound memory in or after 3GB and even
+	 * though the viewport will overlap the outbound memory the controller
+	 * will know to send outbound memory downstream and everything else
+	 * upstream.
+	 *
+	 * For example:
+	 *
+	 * - The best-case scenario, memory up to 3GB, is to place the inbound
+	 *   region in the first 4GB of pcie-space, as some legacy devices can
+	 *   only address 32bits. We would also like to put the MSI under 4GB
+	 *   as well, since some devices require a 32bit MSI target address.
+	 *
+	 * - If the system memory is 4GB or larger we cannot start the inbound
+	 *   region at location 0 (since we have to allow some space for
+	 *   outbound memory @ 3GB). So instead it will  start at the 1x
+	 *   multiple of its size
+	 */
+	if (!*rc_bar2_size || *rc_bar2_offset % *rc_bar2_size ||
+	    (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
+		dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
+			*rc_bar2_size, *rc_bar2_offset);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int brcm_pcie_setup(struct brcm_pcie *pcie)
+{
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+	u64 rc_bar2_offset, rc_bar2_size;
+	void __iomem *base = pcie->base;
+	struct device *dev = pcie->dev;
+	struct resource_entry *entry;
+	unsigned int scb_size_val;
+	bool ssc_good = false;
+	struct resource *res;
+	int num_out_wins = 0;
+	u16 nlw, cls, lnksta;
+	int i, ret;
+	u32 tmp;
+
+	/* Reset the bridge */
+	brcm_pcie_bridge_sw_init_set(pcie, 1);
+
+	usleep_range(100, 200);
+
+	/* Take the bridge out of reset */
+	brcm_pcie_bridge_sw_init_set(pcie, 0);
+
+	WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, SERDES_IDDQ, 0);
+	/* Wait for SerDes to be stable */
+	usleep_range(100, 200);
+
+	/* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
+	tmp = INSERT_FIELD(0, PCIE_MISC_MISC_CTRL, SCB_ACCESS_EN, 1);
+	tmp = INSERT_FIELD(tmp, PCIE_MISC_MISC_CTRL, CFG_READ_UR_MODE, 1);
+	tmp = INSERT_FIELD(tmp, PCIE_MISC_MISC_CTRL, MAX_BURST_SIZE,
+			   BURST_SIZE_128);
+	bcm_writel(tmp, base + PCIE_MISC_MISC_CTRL);
+
+	ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
+						    &rc_bar2_offset);
+	if (ret)
+		return ret;
+
+	tmp = lower_32_bits(rc_bar2_offset);
+	tmp = INSERT_FIELD(tmp, PCIE_MISC_RC_BAR2_CONFIG_LO, SIZE,
+			   brcm_pcie_encode_ibar_size(rc_bar2_size));
+	bcm_writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
+	bcm_writel(upper_32_bits(rc_bar2_offset),
+		   base + PCIE_MISC_RC_BAR2_CONFIG_HI);
+
+	scb_size_val = rc_bar2_size ?
+		       ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
+	WR_FLD(base, PCIE_MISC_MISC_CTRL, SCB0_SIZE, scb_size_val);
+
+	/* disable the PCIe->GISB memory window (RC_BAR1) */
+	WR_FLD(base, PCIE_MISC_RC_BAR1_CONFIG_LO, SIZE, 0);
+
+	/* disable the PCIe->SCB memory window (RC_BAR3) */
+	WR_FLD(base, PCIE_MISC_RC_BAR3_CONFIG_LO, SIZE, 0);
+
+	/* clear any interrupts we find on boot */
+	bcm_writel(0xffffffff, base + PCIE_INTR2_CPU_BASE + CLR);
+	(void)bcm_readl(base + PCIE_INTR2_CPU_BASE + CLR);
+
+	/* Mask all interrupts since we are not handling any yet */
+	bcm_writel(0xffffffff, base + PCIE_INTR2_CPU_BASE + MASK_SET);
+	(void)bcm_readl(base + PCIE_INTR2_CPU_BASE + MASK_SET);
+
+	if (pcie->gen)
+		brcm_pcie_set_gen(base, pcie->gen);
+
+	/* Unassert the fundamental reset */
+	brcm_pcie_perst_set(pcie, 0);
+
+	/*
+	 * Give the RC/EP time to wake up, before trying to configure RC.
+	 * Intermittently check status for link-up, up to a total of 100ms.
+	 */
+	for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
+		msleep(5);
+
+	if (!brcm_pcie_link_up(pcie)) {
+		dev_info(dev, "link down\n");
+		return -ENODEV;
+	}
+
+	if (!brcm_pcie_rc_mode(pcie)) {
+		dev_err(dev, "PCIe misconfigured; is in EP mode\n");
+		return -EINVAL;
+	}
+
+	resource_list_for_each_entry(entry, &bridge->windows) {
+		res = entry->res;
+
+		if (resource_type(res) != IORESOURCE_MEM)
+			continue;
+
+		if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
+			dev_err(pcie->dev, "too many outbound wins\n");
+			return -EINVAL;
+		}
+
+		brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
+					   res->start - entry->offset,
+					   res->end - res->start + 1);
+		num_out_wins++;
+	}
+
+	/*
+	 * For config space accesses on the RC, show the right class for
+	 * a PCIe-PCIe bridge (the default setting is to be EP mode).
+	 */
+	WR_FLD_RB(base, PCIE_RC_CFG_PRIV1_ID_VAL3, CLASS_CODE, 0x060400);
+
+	if (pcie->ssc) {
+		ret = brcm_pcie_set_ssc(base);
+		if (ret == 0)
+			ssc_good = true;
+		else
+			dev_err(dev, "failed attempt to enter ssc mode\n");
+	}
+
+	lnksta = bcm_readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
+	cls = lnksta & PCI_EXP_LNKSTA_CLS;
+	nlw = (lnksta & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT;
+	dev_info(dev, "link up, %s x%u %s\n",
+		 PCIE_SPEED2STR(cls + PCI_SPEED_133MHz_PCIX_533),
+		 nlw, ssc_good ? "(SSC)" : "(!SSC)");
+
+	/* PCIe->SCB endian mode for BAR */
+	/* field ENDIAN_MODE_BAR2 = DATA_ENDIAN */
+	WR_FLD_RB(base, PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1,
+		  ENDIAN_MODE_BAR2, DATA_ENDIAN);
+
+	/*
+	 * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
+	 * is enabled =>  setting the CLKREQ_DEBUG_ENABLE field to 1.
+	 */
+	WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, CLKREQ_DEBUG_ENABLE, 1);
+
+	return 0;
+}
+
+/* L23 is a low-power PCIe link state */
+static void brcm_pcie_enter_l23(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	int l23, i;
+
+	/* assert request for L23 */
+	WR_FLD_RB(base, PCIE_MISC_PCIE_CTRL, PCIE_L23_REQUEST, 1);
+
+	/* Wait up to 36 msec for L23 */
+	l23 = RD_FLD(base, PCIE_MISC_PCIE_STATUS, PCIE_LINK_IN_L23);
+	for (i = 0; i < 15 && !l23; i++) {
+		usleep_range(2000, 2400);
+		l23 = RD_FLD(base, PCIE_MISC_PCIE_STATUS, PCIE_LINK_IN_L23);
+	}
+
+	if (!l23)
+		dev_err(pcie->dev, "failed to enter low-power link state\n");
+}
+
+static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+
+	if (brcm_pcie_link_up(pcie))
+		brcm_pcie_enter_l23(pcie);
+	/* Assert fundamental reset */
+	brcm_pcie_perst_set(pcie, 1);
+	/* Deassert request for L23 in case it was asserted */
+	WR_FLD_RB(base, PCIE_MISC_PCIE_CTRL, PCIE_L23_REQUEST, 0);
+	/* Turn off SerDes */
+	WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, SERDES_IDDQ, 1);
+	/* Shutdown PCIe bridge */
+	brcm_pcie_bridge_sw_init_set(pcie, 1);
+}
+
+static void __brcm_pcie_remove(struct brcm_pcie *pcie)
+{
+	brcm_pcie_turn_off(pcie);
+	clk_disable_unprepare(pcie->clk);
+	clk_put(pcie->clk);
+}
+
+static int brcm_pcie_remove(struct platform_device *pdev)
+{
+	struct brcm_pcie *pcie = platform_get_drvdata(pdev);
+
+	pci_stop_root_bus(pcie->root_bus);
+	pci_remove_root_bus(pcie->root_bus);
+	__brcm_pcie_remove(pcie);
+
+	return 0;
+}
+
+static const struct of_device_id brcm_pcie_match[] = {
+	{ .compatible = "brcm,bcm2711-pcie", .data = &bcm2711_cfg },
+	{},
+};
+MODULE_DEVICE_TABLE(of, brcm_pcie_match);
+
+static int brcm_pcie_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const struct pcie_cfg_data *data;
+	struct pci_host_bridge *bridge;
+	struct brcm_pcie *pcie;
+	struct pci_bus *child;
+	struct resource *res;
+	int ret;
+
+	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
+	if (!bridge)
+		return -ENOMEM;
+
+	pcie = pci_host_bridge_priv(bridge);
+
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data) {
+		dev_err(&pdev->dev, "failed to look up compatible string\n");
+		return -EINVAL;
+	}
+
+	pcie->reg_offsets = data->offsets;
+	pcie->reg_field_info = data->reg_field_info;
+	pcie->type = data->type;
+	pcie->np = np;
+	pcie->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcie->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pcie->base))
+		return PTR_ERR(pcie->base);
+
+	pcie->clk = devm_clk_get_optional(&pdev->dev, "sw_pcie");
+	if (IS_ERR(pcie->clk))
+		return PTR_ERR(pcie->clk);
+
+	ret = of_pci_get_max_link_speed(np);
+	pcie->gen = (ret < 0) ? 0 : ret;
+
+	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
+
+	ret = pci_parse_request_of_pci_ranges(pcie->dev, &bridge->windows,
+					      &bridge->dma_ranges, NULL);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(pcie->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "could not enable clock\n");
+		return ret;
+	}
+
+	ret = brcm_pcie_setup(pcie);
+	if (ret)
+		goto fail;
+
+	bridge->dev.parent = &pdev->dev;
+	bridge->busnr = 0;
+	bridge->ops = &brcm_pcie_ops;
+	bridge->sysdata = pcie;
+	bridge->map_irq = of_irq_parse_and_map_pci;
+	bridge->swizzle_irq = pci_common_swizzle;
+
+	ret = pci_scan_root_bus_bridge(bridge);
+	if (ret < 0) {
+		dev_err(pcie->dev, "Scanning root bridge failed\n");
+		goto fail;
+	}
+
+	pci_assign_unassigned_bus_resources(bridge->bus);
+	list_for_each_entry(child, &bridge->bus->children, node)
+		pcie_bus_configure_settings(child);
+	pci_bus_add_devices(bridge->bus);
+	platform_set_drvdata(pdev, pcie);
+	pcie->root_bus = bridge->bus;
+
+	return 0;
+fail:
+	__brcm_pcie_remove(pcie);
+	return ret;
+}
+
+static struct platform_driver brcm_pcie_driver = {
+	.probe = brcm_pcie_probe,
+	.remove = brcm_pcie_remove,
+	.driver = {
+		.name = "brcm-pcie",
+		.of_match_table = brcm_pcie_match,
+	},
+};
+
+module_platform_driver(brcm_pcie_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
+MODULE_AUTHOR("Broadcom");
-- 
2.24.0

