在 2016/11/23 10:08, Brian Norris 写道:
On Wed, Nov 23, 2016 at 09:19:13AM +0800, Shawn Lin wrote:
This patch adds system PM support for Rockchip's RC.
For pre S3, the EP is configured into D3 state which guarantees
the link state should be in L1. So we could send PME_Turn_Off message
to the EP and wait for its ACK to make the link state into L2 or L3
without the aux-supply. This could help save more power which I think
should be very important for mobile devices.
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/pci/host/pcie-rockchip.c | 90 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 89 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index 71d056d..720535b 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -20,6 +20,7 @@
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
+#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
@@ -55,6 +56,10 @@
#define PCIE_CLIENT_MODE_RC HIWORD_UPDATE_BIT(0x0040)
#define PCIE_CLIENT_GEN_SEL_1 HIWORD_UPDATE(0x0080, 0)
#define PCIE_CLIENT_GEN_SEL_2 HIWORD_UPDATE_BIT(0x0080)
+#define PCIE_CLIENT_DEBUG_OUT_0 (PCIE_CLIENT_BASE + 0x3c)
+#define PCIE_CLIENT_DEBUG_LTSSM_MASK GENMASK(5, 0)
+#define PCIE_CLIENT_DEBUG_LTSSM_L1 0x18
+#define PCIE_CLIENT_DEBUG_LTSSM_L2 0x19
#define PCIE_CLIENT_BASIC_STATUS1 (PCIE_CLIENT_BASE + 0x48)
#define PCIE_CLIENT_LINK_STATUS_UP 0x00300000
#define PCIE_CLIENT_LINK_STATUS_MASK 0x00300000
@@ -173,6 +178,7 @@
#define MAX_AXI_IB_ROOTPORT_REGION_NUM 3
#define MIN_AXI_ADDR_BITS_PASSED 8
+#define PCIE_RC_SEND_PME_OFF 0x11960
#define ROCKCHIP_VENDOR_ID 0x1d87
#define PCIE_ECAM_BUS(x) (((x) & 0xff) << 20)
#define PCIE_ECAM_DEV(x) (((x) & 0x1f) << 15)
@@ -181,6 +187,9 @@
#define PCIE_ECAM_ADDR(bus, dev, func, reg) \
(PCIE_ECAM_BUS(bus) | PCIE_ECAM_DEV(dev) | \
PCIE_ECAM_FUNC(func) | PCIE_ECAM_REG(reg))
+#define PCIE_LINK_IS_L2(x) \
+ ((x & PCIE_CLIENT_DEBUG_LTSSM_MASK) == \
Wrap the 'x' in parentheses, for safety in case the caller passes
something complicated.
Will fix.
+ PCIE_CLIENT_DEBUG_LTSSM_L2)
#define RC_REGION_0_ADDR_TRANS_H 0x00000000
#define RC_REGION_0_ADDR_TRANS_L 0x00000000
@@ -1205,9 +1214,80 @@ static int rockchip_cfg_atu(struct rockchip_pcie *rockchip)
AXI_WRAPPER_NOR_MSG,
20 - 1, 0, 0);
rockchip->msg_region = ioremap(rockchip->mem_bus_addr +
- ((reg_no - 1) << 20), SZ_1M);
+ ((reg_no + offset) << 20), SZ_1M);
^^^ You're leaking this, now that you call rockchip_cfg_atu() every
time you resume.
return err;
}
+
+static int rockchip_pcie_wait_l2(struct rockchip_pcie *rockchip)
+{
+ u32 value;
+ int err;
+
+ /* send PME_TURN_OFF message */
+ writel(0x0, rockchip->msg_region + PCIE_RC_SEND_PME_OFF);
+
+ /* read LTSSM and wait for falling into L2 link state */
+ err = readl_poll_timeout(rockchip->apb_base + PCIE_CLIENT_DEBUG_OUT_0,
+ value, PCIE_LINK_IS_L2(value), 20,
+ jiffies_to_usecs(5 * HZ));
You really want to wait a whole 5 seconds for this? Last I saw, you were
doing testing with about 500ms or less. As I read the spec, there's cap
on per-device time to ACK the request, and I recall that was on the
order of 10s of milliseconds. But technically that can add up if you
have a large hierarchy of devices attached...
I have no very clear thought about how long we should set up the
timeout for PME_ACK. As you point out that a large hierarchy of devices
need quite a long time I guess.
A possible work for PCIe core is walk through the hierarchy of devices
and calculate the max ACK timeout(including the latency of HUB).. But
I guess ACPI-base platforms don't need linux-pci to handle L2 stuff at
S3 at all, instead it will be handled by firmware, so still I don't
know how they will calculate it.
+ if (err) {
+ dev_err(rockchip->dev, "PCIe link enter L2 timeout!\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static int rockchip_pcie_suspend_noirq(struct device *dev)
+{
+ struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+ int ret;
+
+ /* disable core and cli int since we don't need to ack PME_ACK */
+ rockchip_pcie_write(rockchip, (PCIE_CLIENT_INT_CLI << 16) |
+ PCIE_CLIENT_INT_CLI, PCIE_CLIENT_INT_MASK);
+ rockchip_pcie_write(rockchip, (u32)PCIE_CORE_INT, PCIE_CORE_INT_MASK);
+
+ ret = rockchip_pcie_wait_l2(rockchip);
+ if (ret)
+ return ret;
You leave core and client interrupts masked if you timeout here?
Woops, will fix it.
Brian
+
+ phy_power_off(rockchip->phy);
+ phy_exit(rockchip->phy);
+
+ clk_disable_unprepare(rockchip->clk_pcie_pm);
+ clk_disable_unprepare(rockchip->hclk_pcie);
+ clk_disable_unprepare(rockchip->aclk_perf_pcie);
+ clk_disable_unprepare(rockchip->aclk_pcie);
+
+ return ret;
+}
+
+static int rockchip_pcie_resume_noirq(struct device *dev)
+{
+ struct rockchip_pcie *rockchip = dev_get_drvdata(dev);
+ int err;
+
+ clk_prepare_enable(rockchip->clk_pcie_pm);
+ clk_prepare_enable(rockchip->hclk_pcie);
+ clk_prepare_enable(rockchip->aclk_perf_pcie);
+ clk_prepare_enable(rockchip->aclk_pcie);
+
+ err = rockchip_pcie_init_port(rockchip);
+ if (err)
+ return err;
+
+ err = rockchip_cfg_atu(rockchip);
+ if (err)
+ return err;
+
+ /* Need this to enter L1 again */
+ rockchip_pcie_update_txcredit_mui(rockchip);
+ rockchip_pcie_enable_interrupts(rockchip);
+
+ return 0;
+}
+
static int rockchip_pcie_probe(struct platform_device *pdev)
{
struct rockchip_pcie *rockchip;
@@ -1228,6 +1308,8 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
if (!rockchip)
return -ENOMEM;
+ platform_set_drvdata(pdev, rockchip);
+
rockchip->dev = dev;
err = rockchip_pcie_parse_dt(rockchip);
@@ -1352,6 +1434,11 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
return err;
}
+static const struct dev_pm_ops rockchip_pcie_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_pcie_suspend_noirq,
+ rockchip_pcie_resume_noirq)
+};
+
static const struct of_device_id rockchip_pcie_of_match[] = {
{ .compatible = "rockchip,rk3399-pcie", },
{}
@@ -1361,6 +1448,7 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
.driver = {
.name = "rockchip-pcie",
.of_match_table = rockchip_pcie_of_match,
+ .pm = &rockchip_pcie_pm_ops,
},
.probe = rockchip_pcie_probe,
--
1.9.1
--
Best Regards
Shawn Lin
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