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linux-next/drivers/ata/ahci_brcmstb.c
Danesh Petigara fb32963355 drivers: ata: wake port before DMA stop for ALPM 
The AHCI driver code stops and starts port DMA engines at will
without considering the power state of the particular port. The
AHCI specification isn't very clear on how to handle this scenario,
leaving implementation open to interpretation.

Broadcom's STB SATA host controller is unable to handle port DMA
controller restarts when the port in question is in low power mode.
When a port enters partial or slumber mode, its PHY is powered down.
When a controller restart is requested, the controller's internal
state machine expects the PHY to be brought back up by software which
never happens in this case, resulting in failures.

To avoid this situation, logic is added to manually wake up the port
just before its DMA engine is stopped, if the port happens to be in
a low power state. HBA initiated power management ensures that the port
eventually returns to its configured low power state, when the link is
idle (as per the conditions listed in the spec). A new host flag is also
added to ensure this logic is only exercised for hosts with the above
limitation.

tj: Formatting changes.

Signed-off-by: Danesh Petigara <dpetigara@broadcom.com>
Reviewed-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-01-25 15:20:44 -05:00

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/*
* Broadcom SATA3 AHCI Controller Driver
*
* Copyright © 2009-2015 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/ahci_platform.h>
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/libata.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include "ahci.h"
#define DRV_NAME "brcm-ahci"
#define SATA_TOP_CTRL_VERSION 0x0
#define SATA_TOP_CTRL_BUS_CTRL 0x4
#define MMIO_ENDIAN_SHIFT 0 /* CPU->AHCI */
#define DMADESC_ENDIAN_SHIFT 2 /* AHCI->DDR */
#define DMADATA_ENDIAN_SHIFT 4 /* AHCI->DDR */
#define PIODATA_ENDIAN_SHIFT 6
#define ENDIAN_SWAP_NONE 0
#define ENDIAN_SWAP_FULL 2
#define OVERRIDE_HWINIT BIT(16)
#define SATA_TOP_CTRL_TP_CTRL 0x8
#define SATA_TOP_CTRL_PHY_CTRL 0xc
#define SATA_TOP_CTRL_PHY_CTRL_1 0x0
#define SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE BIT(14)
#define SATA_TOP_CTRL_PHY_CTRL_2 0x4
#define SATA_TOP_CTRL_2_SW_RST_MDIOREG BIT(0)
#define SATA_TOP_CTRL_2_SW_RST_OOB BIT(1)
#define SATA_TOP_CTRL_2_SW_RST_RX BIT(2)
#define SATA_TOP_CTRL_2_SW_RST_TX BIT(3)
#define SATA_TOP_CTRL_2_PHY_GLOBAL_RESET BIT(14)
#define SATA_TOP_CTRL_PHY_OFFS 0x8
#define SATA_TOP_MAX_PHYS 2
#define SATA_FIRST_PORT_CTRL 0x700
#define SATA_NEXT_PORT_CTRL_OFFSET 0x80
#define SATA_PORT_PCTRL6(reg_base) (reg_base + 0x18)
/* On big-endian MIPS, buses are reversed to big endian, so switch them back */
#if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
#define DATA_ENDIAN 2 /* AHCI->DDR inbound accesses */
#define MMIO_ENDIAN 2 /* CPU->AHCI outbound accesses */
#else
#define DATA_ENDIAN 0
#define MMIO_ENDIAN 0
#endif
#define BUS_CTRL_ENDIAN_CONF \
((DATA_ENDIAN << DMADATA_ENDIAN_SHIFT) | \
(DATA_ENDIAN << DMADESC_ENDIAN_SHIFT) | \
(MMIO_ENDIAN << MMIO_ENDIAN_SHIFT))
enum brcm_ahci_quirks {
BRCM_AHCI_QUIRK_NO_NCQ = BIT(0),
BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE = BIT(1),
};
struct brcm_ahci_priv {
struct device *dev;
void __iomem *top_ctrl;
u32 port_mask;
u32 quirks;
};
static const struct ata_port_info ahci_brcm_port_info = {
.flags = AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM,
.link_flags = ATA_LFLAG_NO_DB_DELAY,
.pio_mask = ATA_PIO4,
.udma_mask = ATA_UDMA6,
.port_ops = &ahci_platform_ops,
};
static inline u32 brcm_sata_readreg(void __iomem *addr)
{
/*
* MIPS endianness is configured by boot strap, which also reverses all
* bus endianness (i.e., big-endian CPU + big endian bus ==> native
* endian I/O).
*
* Other architectures (e.g., ARM) either do not support big endian, or
* else leave I/O in little endian mode.
*/
if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
return __raw_readl(addr);
else
return readl_relaxed(addr);
}
static inline void brcm_sata_writereg(u32 val, void __iomem *addr)
{
/* See brcm_sata_readreg() comments */
if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
__raw_writel(val, addr);
else
writel_relaxed(val, addr);
}
static void brcm_sata_alpm_init(struct ahci_host_priv *hpriv)
{
struct brcm_ahci_priv *priv = hpriv->plat_data;
u32 bus_ctrl, port_ctrl, host_caps;
int i;
/* Enable support for ALPM */
bus_ctrl = brcm_sata_readreg(priv->top_ctrl +
SATA_TOP_CTRL_BUS_CTRL);
brcm_sata_writereg(bus_ctrl | OVERRIDE_HWINIT,
priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL);
host_caps = readl(hpriv->mmio + HOST_CAP);
writel(host_caps | HOST_CAP_ALPM, hpriv->mmio);
brcm_sata_writereg(bus_ctrl, priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL);
/*
* Adjust timeout to allow PLL sufficient time to lock while waking
* up from slumber mode.
*/
for (i = 0, port_ctrl = SATA_FIRST_PORT_CTRL;
i < SATA_TOP_MAX_PHYS;
i++, port_ctrl += SATA_NEXT_PORT_CTRL_OFFSET) {
if (priv->port_mask & BIT(i))
writel(0xff1003fc,
hpriv->mmio + SATA_PORT_PCTRL6(port_ctrl));
}
}
static void brcm_sata_phy_enable(struct brcm_ahci_priv *priv, int port)
{
void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
(port * SATA_TOP_CTRL_PHY_OFFS);
void __iomem *p;
u32 reg;
if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
return;
/* clear PHY_DEFAULT_POWER_STATE */
p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
reg = brcm_sata_readreg(p);
reg &= ~SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
brcm_sata_writereg(reg, p);
/* reset the PHY digital logic */
p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
reg = brcm_sata_readreg(p);
reg &= ~(SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
SATA_TOP_CTRL_2_SW_RST_RX);
reg |= SATA_TOP_CTRL_2_SW_RST_TX;
brcm_sata_writereg(reg, p);
reg = brcm_sata_readreg(p);
reg |= SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
brcm_sata_writereg(reg, p);
reg = brcm_sata_readreg(p);
reg &= ~SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
brcm_sata_writereg(reg, p);
(void)brcm_sata_readreg(p);
}
static void brcm_sata_phy_disable(struct brcm_ahci_priv *priv, int port)
{
void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
(port * SATA_TOP_CTRL_PHY_OFFS);
void __iomem *p;
u32 reg;
if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
return;
/* power-off the PHY digital logic */
p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
reg = brcm_sata_readreg(p);
reg |= (SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
SATA_TOP_CTRL_2_SW_RST_RX | SATA_TOP_CTRL_2_SW_RST_TX |
SATA_TOP_CTRL_2_PHY_GLOBAL_RESET);
brcm_sata_writereg(reg, p);
/* set PHY_DEFAULT_POWER_STATE */
p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
reg = brcm_sata_readreg(p);
reg |= SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
brcm_sata_writereg(reg, p);
}
static void brcm_sata_phys_enable(struct brcm_ahci_priv *priv)
{
int i;
for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
if (priv->port_mask & BIT(i))
brcm_sata_phy_enable(priv, i);
}
static void brcm_sata_phys_disable(struct brcm_ahci_priv *priv)
{
int i;
for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
if (priv->port_mask & BIT(i))
brcm_sata_phy_disable(priv, i);
}
static u32 brcm_ahci_get_portmask(struct platform_device *pdev,
struct brcm_ahci_priv *priv)
{
void __iomem *ahci;
struct resource *res;
u32 impl;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ahci");
ahci = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(ahci))
return 0;
impl = readl(ahci + HOST_PORTS_IMPL);
if (fls(impl) > SATA_TOP_MAX_PHYS)
dev_warn(priv->dev, "warning: more ports than PHYs (%#x)\n",
impl);
else if (!impl)
dev_info(priv->dev, "no ports found\n");
devm_iounmap(&pdev->dev, ahci);
devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
return impl;
}
static void brcm_sata_init(struct brcm_ahci_priv *priv)
{
/* Configure endianness */
brcm_sata_writereg(BUS_CTRL_ENDIAN_CONF,
priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL);
}
#ifdef CONFIG_PM_SLEEP
static int brcm_ahci_suspend(struct device *dev)
{
struct ata_host *host = dev_get_drvdata(dev);
struct ahci_host_priv *hpriv = host->private_data;
struct brcm_ahci_priv *priv = hpriv->plat_data;
int ret;
ret = ahci_platform_suspend(dev);
brcm_sata_phys_disable(priv);
return ret;
}
static int brcm_ahci_resume(struct device *dev)
{
struct ata_host *host = dev_get_drvdata(dev);
struct ahci_host_priv *hpriv = host->private_data;
struct brcm_ahci_priv *priv = hpriv->plat_data;
brcm_sata_init(priv);
brcm_sata_phys_enable(priv);
brcm_sata_alpm_init(hpriv);
return ahci_platform_resume(dev);
}
#endif
static struct scsi_host_template ahci_platform_sht = {
AHCI_SHT(DRV_NAME),
};
static int brcm_ahci_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct brcm_ahci_priv *priv;
struct ahci_host_priv *hpriv;
struct resource *res;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "top-ctrl");
priv->top_ctrl = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->top_ctrl))
return PTR_ERR(priv->top_ctrl);
if (of_device_is_compatible(dev->of_node, "brcm,bcm7425-ahci")) {
priv->quirks |= BRCM_AHCI_QUIRK_NO_NCQ;
priv->quirks |= BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE;
}
brcm_sata_init(priv);
priv->port_mask = brcm_ahci_get_portmask(pdev, priv);
if (!priv->port_mask)
return -ENODEV;
brcm_sata_phys_enable(priv);
hpriv = ahci_platform_get_resources(pdev);
if (IS_ERR(hpriv))
return PTR_ERR(hpriv);
hpriv->plat_data = priv;
hpriv->flags = AHCI_HFLAG_WAKE_BEFORE_STOP;
brcm_sata_alpm_init(hpriv);
ret = ahci_platform_enable_resources(hpriv);
if (ret)
return ret;
if (priv->quirks & BRCM_AHCI_QUIRK_NO_NCQ)
hpriv->flags |= AHCI_HFLAG_NO_NCQ;
ret = ahci_platform_init_host(pdev, hpriv, &ahci_brcm_port_info,
&ahci_platform_sht);
if (ret)
return ret;
dev_info(dev, "Broadcom AHCI SATA3 registered\n");
return 0;
}
static int brcm_ahci_remove(struct platform_device *pdev)
{
struct ata_host *host = dev_get_drvdata(&pdev->dev);
struct ahci_host_priv *hpriv = host->private_data;
struct brcm_ahci_priv *priv = hpriv->plat_data;
int ret;
ret = ata_platform_remove_one(pdev);
if (ret)
return ret;
brcm_sata_phys_disable(priv);
return 0;
}
static const struct of_device_id ahci_of_match[] = {
{.compatible = "brcm,bcm7425-ahci"},
{.compatible = "brcm,bcm7445-ahci"},
{},
};
MODULE_DEVICE_TABLE(of, ahci_of_match);
static SIMPLE_DEV_PM_OPS(ahci_brcm_pm_ops, brcm_ahci_suspend, brcm_ahci_resume);
static struct platform_driver brcm_ahci_driver = {
.probe = brcm_ahci_probe,
.remove = brcm_ahci_remove,
.driver = {
.name = DRV_NAME,
.of_match_table = ahci_of_match,
.pm = &ahci_brcm_pm_ops,
},
};
module_platform_driver(brcm_ahci_driver);
MODULE_DESCRIPTION("Broadcom SATA3 AHCI Controller Driver");
MODULE_AUTHOR("Brian Norris");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:sata-brcmstb");
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