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PCI: tegra: Add loadable kernel module support

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Implement remove callback function for Tegra PCIe driver to add
loadable kernel module support.

Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port should broadcast PME_Turn_Off
message before PCIe link goes to L2. PME_Turn_Off broadcast mechanism is
implemented in AFI module. Each Tegra PCIe root port has its own
PME_Turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
register to broadcast PME_Turn_Off message.

Once PME_TO_Ack is recieved driver will turn OFF PCIe clock, power gate
PCIe partition and turn OFF regulators.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Manikanta Maddireddy 2018-02-28 15:30:33 +05:30 committed by Lorenzo Pieralisi
parent 527557a44c
commit 662b94c319
1 changed files with 100 additions and 3 deletions
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103
drivers/pci/host/pci-tegra.c
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@ -18,10 +18,12 @@
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@ -139,6 +141,8 @@
#define AFI_INTR_EN_FPCI_TIMEOUT (1 << 7)
#define AFI_INTR_EN_PRSNT_SENSE (1 << 8)
#define AFI_PCIE_PME 0xf0
#define AFI_PCIE_CONFIG 0x0f8
#define AFI_PCIE_CONFIG_PCIE_DISABLE(x) (1 << ((x) + 1))
#define AFI_PCIE_CONFIG_PCIE_DISABLE_ALL 0xe
@ -219,6 +223,8 @@
#define PADS_REFCLK_CFG_PREDI_SHIFT 8 /* 11:8 */
#define PADS_REFCLK_CFG_DRVI_SHIFT 12 /* 15:12 */
#define PME_ACK_TIMEOUT 10000
struct tegra_msi {
struct msi_controller chip;
DECLARE_BITMAP(used, INT_PCI_MSI_NR);
@ -230,8 +236,16 @@ struct tegra_msi {
};
/* used to differentiate between Tegra SoC generations */
struct tegra_pcie_port_soc {
struct {
u8 turnoff_bit;
u8 ack_bit;
} pme;
};
struct tegra_pcie_soc {
unsigned int num_ports;
const struct tegra_pcie_port_soc *ports;
unsigned int msi_base_shift;
u32 pads_pll_ctl;
u32 tx_ref_sel;
@ -1344,6 +1358,32 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
return 0;
}
static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
{
struct tegra_pcie *pcie = port->pcie;
const struct tegra_pcie_soc *soc = pcie->soc;
int err;
u32 val;
u8 ack_bit;
val = afi_readl(pcie, AFI_PCIE_PME);
val |= (0x1 << soc->ports[port->index].pme.turnoff_bit);
afi_writel(pcie, val, AFI_PCIE_PME);
ack_bit = soc->ports[port->index].pme.ack_bit;
err = readl_poll_timeout(pcie->afi + AFI_PCIE_PME, val,
val & (0x1 << ack_bit), 1, PME_ACK_TIMEOUT);
if (err)
dev_err(pcie->dev, "PME Ack is not received on port: %d\n",
port->index);
usleep_range(10000, 11000);
val = afi_readl(pcie, AFI_PCIE_PME);
val &= ~(0x1 << soc->ports[port->index].pme.turnoff_bit);
afi_writel(pcie, val, AFI_PCIE_PME);
}
static int tegra_msi_alloc(struct tegra_msi *chip)
{
int msi;
@ -2089,8 +2129,14 @@ static void tegra_pcie_disable_ports(struct tegra_pcie *pcie)
}
}
static const struct tegra_pcie_port_soc tegra20_pcie_ports[] = {
{ .pme.turnoff_bit = 0, .pme.ack_bit = 5 },
{ .pme.turnoff_bit = 8, .pme.ack_bit = 10 },
};
static const struct tegra_pcie_soc tegra20_pcie = {
.num_ports = 2,
.ports = tegra20_pcie_ports,
.msi_base_shift = 0,
.pads_pll_ctl = PADS_PLL_CTL_TEGRA20,
.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_DIV10,
@ -2104,8 +2150,15 @@ static const struct tegra_pcie_soc tegra20_pcie = {
.program_uphy = true,
};
static const struct tegra_pcie_port_soc tegra30_pcie_ports[] = {
{ .pme.turnoff_bit = 0, .pme.ack_bit = 5 },
{ .pme.turnoff_bit = 8, .pme.ack_bit = 10 },
{ .pme.turnoff_bit = 16, .pme.ack_bit = 18 },
};
static const struct tegra_pcie_soc tegra30_pcie = {
.num_ports = 3,
.ports = tegra30_pcie_ports,
.msi_base_shift = 8,
.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
@ -2122,6 +2175,7 @@ static const struct tegra_pcie_soc tegra30_pcie = {
static const struct tegra_pcie_soc tegra124_pcie = {
.num_ports = 2,
.ports = tegra20_pcie_ports,
.msi_base_shift = 8,
.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
@ -2137,6 +2191,7 @@ static const struct tegra_pcie_soc tegra124_pcie = {
static const struct tegra_pcie_soc tegra210_pcie = {
.num_ports = 2,
.ports = tegra20_pcie_ports,
.msi_base_shift = 8,
.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
@ -2150,8 +2205,15 @@ static const struct tegra_pcie_soc tegra210_pcie = {
.program_uphy = true,
};
static const struct tegra_pcie_port_soc tegra186_pcie_ports[] = {
{ .pme.turnoff_bit = 0, .pme.ack_bit = 5 },
{ .pme.turnoff_bit = 8, .pme.ack_bit = 10 },
{ .pme.turnoff_bit = 12, .pme.ack_bit = 14 },
};
static const struct tegra_pcie_soc tegra186_pcie = {
.num_ports = 3,
.ports = tegra186_pcie_ports,
.msi_base_shift = 8,
.pads_pll_ctl = PADS_PLL_CTL_TEGRA30,
.tx_ref_sel = PADS_PLL_CTL_TXCLKREF_BUF_EN,
@ -2263,6 +2325,12 @@ static const struct file_operations tegra_pcie_ports_ops = {
.release = seq_release,
};
static void tegra_pcie_debugfs_exit(struct tegra_pcie *pcie)
{
debugfs_remove_recursive(pcie->debugfs);
pcie->debugfs = NULL;
}
static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
{
struct dentry *file;
@ -2279,8 +2347,7 @@ static int tegra_pcie_debugfs_init(struct tegra_pcie *pcie)
return 0;
remove:
debugfs_remove_recursive(pcie->debugfs);
pcie->debugfs = NULL;
tegra_pcie_debugfs_exit(pcie);
return -ENOMEM;
}
@ -2298,6 +2365,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
pcie = pci_host_bridge_priv(host);
host->sysdata = pcie;
platform_set_drvdata(pdev, pcie);
pcie->soc = of_device_get_match_data(dev);
INIT_LIST_HEAD(&pcie->ports);
@ -2375,6 +2443,33 @@ put_resources:
return err;
}
static int tegra_pcie_remove(struct platform_device *pdev)
{
struct tegra_pcie *pcie = platform_get_drvdata(pdev);
struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
struct tegra_pcie_port *port;
if (IS_ENABLED(CONFIG_DEBUG_FS))
tegra_pcie_debugfs_exit(pcie);
pci_stop_root_bus(host->bus);
pci_remove_root_bus(host->bus);
list_for_each_entry(port, &pcie->ports, list)
tegra_pcie_pme_turnoff(port);
tegra_pcie_disable_ports(pcie);
if (IS_ENABLED(CONFIG_PCI_MSI))
tegra_pcie_disable_msi(pcie);
tegra_pcie_free_resources(pcie);
tegra_pcie_disable_controller(pcie);
tegra_pcie_put_resources(pcie);
return 0;
}
static struct platform_driver tegra_pcie_driver = {
.driver = {
.name = "tegra-pcie",
@ -2382,5 +2477,7 @@ static struct platform_driver tegra_pcie_driver = {
.suppress_bind_attrs = true,
},
.probe = tegra_pcie_probe,
.remove = tegra_pcie_remove,
};
builtin_platform_driver(tegra_pcie_driver);
module_platform_driver(tegra_pcie_driver);
MODULE_LICENSE("GPL");