* [PATCH v8 0/4] i.MX7 PCI support
@ 2017-03-28 15:42 Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 1/4] PCI: imx6: Add code to support i.MX7D Andrey Smirnov
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Andrey Smirnov @ 2017-03-28 15:42 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Andrey Smirnov, linux-pci, yurovsky, Lucas Stach, Fabio Estevam,
Dong Aisheng, Rob Herring, linux-arm-kernel, linux-kernel
Hello, everyone:
This is a eightth iteration of the code that adds PCI-subsystem bits
necessary for enabling PCI support on i.MX7.
NOTE: To test this patchset with real i.MX7 hardware, additional
patches, that are being upstreamed via different trees, are needed. Full
working tree is availible at:
https://github.com/ndreys/linux/tree/imx7d/pcie-support-v8
Changes since v7 (can be found at [version7]):
- Collected Reviewed-by for the whole series from Lucas
Changes since v6 (can be found at [version6]):
- Rebased against latest changes in 'next' of PCI subsystem
git tree
Chagnes since v5 (can be found at [version5]):
- Collected ACKs from Lee and Rob
Changes since v4 (can be found at [version4]):
- Dropped typo-fix patch (originally patch #1 of the
series).
- Added patch with workaround to address speed change false
failures (I kept it as a separate patch to better document
exchange with NXP/Freescale that lead to that patch)
- Added patch to avoid speed change on links configured Gen1
only (Let me know if that is a terrible idea)
- Addressed section mismatch problem by moving call to
hook_fault_code to happend before driver registration.
Changes since v3 (can be found at [version3]):
- Move all of the reset_control_assert's into imx6_pcie_assert_core_reset
- Documented required reset and power domain DT bindings
Changes since v2 (can be found at [version2]):
- Collected Reviewed-by for patch #2 from Lucas
- Reset logic implementation moved out into a reset controller
driver (see [reset1])
- Removed unused leftover code
Changes since v1 (can be found at [version1]):
- All GPC related code moved into a separate driver (see [gpc1])
- Removed GPIO probe deferral logging
- Fixed section mismatch warning
- Minor reformatting of fsl,imx6q-pcie.txt(as per Rob
Herring's request)
[version7] https://lkml.org/lkml/2017/3/21/331
[version6] https://lkml.org/lkml/2017/3/14/584
[version5] https://lkml.org/lkml/2017/2/20/376
[version4] https://lkml.org/lkml/2017/2/7/478
[version3] https://lkml.org/lkml/2017/2/6/565
[version2] https://lkml.org/lkml/2017/2/1/510
[version1] https://lkml.org/lkml/2017/1/19/488
[gpc1] https://lkml.org/lkml/2017/2/6/551
[reset1] https://lkml.org/lkml/2017/2/6/554
Andrey Smirnov (4):
PCI: imx6: Add code to support i.MX7D
PCI: imx6: Allow probe deferal by reset GPIO
PCI: imx6: Do not wait for speed change on i.MX7
PCI: imx6: Do not switch speed if Gen2 is disabled
.../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 13 +-
drivers/pci/dwc/pci-imx6.c | 198 +++++++++++++++------
include/linux/mfd/syscon/imx7-iomuxc-gpr.h | 4 +
3 files changed, 160 insertions(+), 55 deletions(-)
--
2.9.3
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v8 1/4] PCI: imx6: Add code to support i.MX7D
2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
@ 2017-03-28 15:42 ` Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 2/4] PCI: imx6: Allow probe deferal by reset GPIO Andrey Smirnov
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Andrey Smirnov @ 2017-03-28 15:42 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Andrey Smirnov, yurovsky, Lucas Stach, Rob Herring, Mark Rutland,
Lee Jones, Fabio Estevam, Dong Aisheng, linux-arm-kernel,
devicetree, linux-pci, linux-kernel
Add various bits of code needed to support i.MX7D variant of the IP.
Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
.../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 13 ++-
drivers/pci/dwc/pci-imx6.c | 120 ++++++++++++++++-----
include/linux/mfd/syscon/imx7-iomuxc-gpr.h | 4 +
3 files changed, 111 insertions(+), 26 deletions(-)
diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index 83aeb1f..11db2ab 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -4,7 +4,11 @@ This PCIe host controller is based on the Synopsis Designware PCIe IP
and thus inherits all the common properties defined in designware-pcie.txt.
Required properties:
-- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie", "fsl,imx6qp-pcie"
+- compatible:
+ - "fsl,imx6q-pcie"
+ - "fsl,imx6sx-pcie",
+ - "fsl,imx6qp-pcie"
+ - "fsl,imx7d-pcie"
- reg: base address and length of the PCIe controller
- interrupts: A list of interrupt outputs of the controller. Must contain an
entry for each entry in the interrupt-names property.
@@ -34,6 +38,13 @@ Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
- "pcie_inbound_axi"
+Additional required properties for imx7d-pcie:
+- power-domains: Must be set to a phandle pointing to PCIE_PHY power domain
+- resets: Must contain phandles to PCIE related reset lines exposed by SRC IP block
+- reset-names: Must contain the following entires:
+ - "pciephy"
+ - "apps"
+
Example:
pcie@0x01000000 {
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 801e46c..e0c36d6 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/mfd/syscon/imx7-iomuxc-gpr.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/of_device.h>
@@ -27,6 +28,7 @@
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/interrupt.h>
+#include <linux/reset.h>
#include "pcie-designware.h"
@@ -36,6 +38,7 @@ enum imx6_pcie_variants {
IMX6Q,
IMX6SX,
IMX6QP,
+ IMX7D,
};
struct imx6_pcie {
@@ -47,6 +50,8 @@ struct imx6_pcie {
struct clk *pcie_inbound_axi;
struct clk *pcie;
struct regmap *iomuxc_gpr;
+ struct reset_control *pciephy_reset;
+ struct reset_control *apps_reset;
enum imx6_pcie_variants variant;
u32 tx_deemph_gen1;
u32 tx_deemph_gen2_3p5db;
@@ -56,6 +61,11 @@ struct imx6_pcie {
int link_gen;
};
+/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
+#define PHY_PLL_LOCK_WAIT_MAX_RETRIES 2000
+#define PHY_PLL_LOCK_WAIT_USLEEP_MIN 50
+#define PHY_PLL_LOCK_WAIT_USLEEP_MAX 200
+
/* PCIe Root Complex registers (memory-mapped) */
#define PCIE_RC_LCR 0x7c
#define PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN1 0x1
@@ -248,6 +258,10 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
{
switch (imx6_pcie->variant) {
+ case IMX7D:
+ reset_control_assert(imx6_pcie->pciephy_reset);
+ reset_control_assert(imx6_pcie->apps_reset);
+ break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_TEST_POWERDOWN,
@@ -303,11 +317,32 @@ static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1,
IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16);
break;
+ case IMX7D:
+ break;
}
return ret;
}
+static void imx7d_pcie_wait_for_phy_pll_lock(struct imx6_pcie *imx6_pcie)
+{
+ u32 val;
+ unsigned int retries;
+ struct device *dev = imx6_pcie->pci->dev;
+
+ for (retries = 0; retries < PHY_PLL_LOCK_WAIT_MAX_RETRIES; retries++) {
+ regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR22, &val);
+
+ if (val & IMX7D_GPR22_PCIE_PHY_PLL_LOCKED)
+ return;
+
+ usleep_range(PHY_PLL_LOCK_WAIT_USLEEP_MIN,
+ PHY_PLL_LOCK_WAIT_USLEEP_MAX);
+ }
+
+ dev_err(dev, "PCIe PLL lock timeout\n");
+}
+
static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
{
struct dw_pcie *pci = imx6_pcie->pci;
@@ -351,6 +386,10 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
}
switch (imx6_pcie->variant) {
+ case IMX7D:
+ reset_control_deassert(imx6_pcie->pciephy_reset);
+ imx7d_pcie_wait_for_phy_pll_lock(imx6_pcie);
+ break;
case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR5,
IMX6SX_GPR5_PCIE_BTNRST_RESET, 0);
@@ -377,35 +416,44 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie *imx6_pcie)
static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
{
- if (imx6_pcie->variant == IMX6SX)
+ switch (imx6_pcie->variant) {
+ case IMX7D:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX7D_GPR12_PCIE_PHY_REFCLK_SEL, 0);
+ break;
+ case IMX6SX:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6SX_GPR12_PCIE_RX_EQ_MASK,
IMX6SX_GPR12_PCIE_RX_EQ_2);
+ /* FALLTHROUGH */
+ default:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_PCIE_CTL_2, 0 << 10);
+ /* configure constant input signal to the pcie ctrl and phy */
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
+
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN1,
+ imx6_pcie->tx_deemph_gen1 << 0);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
+ imx6_pcie->tx_deemph_gen2_3p5db << 6);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
+ imx6_pcie->tx_deemph_gen2_6db << 12);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_SWING_FULL,
+ imx6_pcie->tx_swing_full << 18);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
+ IMX6Q_GPR8_TX_SWING_LOW,
+ imx6_pcie->tx_swing_low << 25);
+ break;
+ }
- /* configure constant input signal to the pcie ctrl and phy */
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX6Q_GPR12_DEVICE_TYPE, PCI_EXP_TYPE_ROOT_PORT << 12);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_LOS_LEVEL, 9 << 4);
-
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN1,
- imx6_pcie->tx_deemph_gen1 << 0);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN2_3P5DB,
- imx6_pcie->tx_deemph_gen2_3p5db << 6);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_DEEMPH_GEN2_6DB,
- imx6_pcie->tx_deemph_gen2_6db << 12);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_SWING_FULL,
- imx6_pcie->tx_swing_full << 18);
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR8,
- IMX6Q_GPR8_TX_SWING_LOW,
- imx6_pcie->tx_swing_low << 25);
}
static int imx6_pcie_wait_for_link(struct imx6_pcie *imx6_pcie)
@@ -469,8 +517,11 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
/* Start LTSSM. */
- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
- IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
+ if (imx6_pcie->variant == IMX7D)
+ reset_control_deassert(imx6_pcie->apps_reset);
+ else
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6Q_GPR12_PCIE_CTL_2, 1 << 10);
ret = imx6_pcie_wait_for_link(imx6_pcie);
if (ret)
@@ -653,13 +704,31 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
return PTR_ERR(imx6_pcie->pcie);
}
- if (imx6_pcie->variant == IMX6SX) {
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
imx6_pcie->pcie_inbound_axi = devm_clk_get(dev,
"pcie_inbound_axi");
if (IS_ERR(imx6_pcie->pcie_inbound_axi)) {
dev_err(dev, "pcie_inbound_axi clock missing or invalid\n");
return PTR_ERR(imx6_pcie->pcie_inbound_axi);
}
+ break;
+ case IMX7D:
+ imx6_pcie->pciephy_reset = devm_reset_control_get(dev,
+ "pciephy");
+ if (IS_ERR(imx6_pcie->pciephy_reset)) {
+ dev_err(dev, "Failed to get PCIEPHY reset contol\n");
+ return PTR_ERR(imx6_pcie->pciephy_reset);
+ }
+
+ imx6_pcie->apps_reset = devm_reset_control_get(dev, "apps");
+ if (IS_ERR(imx6_pcie->apps_reset)) {
+ dev_err(dev, "Failed to get PCIE APPS reset contol\n");
+ return PTR_ERR(imx6_pcie->apps_reset);
+ }
+ break;
+ default:
+ break;
}
/* Grab GPR config register range */
@@ -718,6 +787,7 @@ static const struct of_device_id imx6_pcie_of_match[] = {
{ .compatible = "fsl,imx6q-pcie", .data = (void *)IMX6Q, },
{ .compatible = "fsl,imx6sx-pcie", .data = (void *)IMX6SX, },
{ .compatible = "fsl,imx6qp-pcie", .data = (void *)IMX6QP, },
+ { .compatible = "fsl,imx7d-pcie", .data = (void *)IMX7D, },
{},
};
diff --git a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
index 4585d61..abbd524 100644
--- a/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
+++ b/include/linux/mfd/syscon/imx7-iomuxc-gpr.h
@@ -44,4 +44,8 @@
#define IMX7D_GPR5_CSI_MUX_CONTROL_MIPI (0x1 << 4)
+#define IMX7D_GPR12_PCIE_PHY_REFCLK_SEL BIT(5)
+
+#define IMX7D_GPR22_PCIE_PHY_PLL_LOCKED BIT(31)
+
#endif /* __LINUX_IMX7_IOMUXC_GPR_H */
--
2.9.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v8 2/4] PCI: imx6: Allow probe deferal by reset GPIO
2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 1/4] PCI: imx6: Add code to support i.MX7D Andrey Smirnov
@ 2017-03-28 15:42 ` Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 3/4] PCI: imx6: Do not wait for speed change on i.MX7 Andrey Smirnov
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Andrey Smirnov @ 2017-03-28 15:42 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Andrey Smirnov, yurovsky, Lucas Stach, Fabio Estevam,
Dong Aisheng, linux-pci, linux-arm-kernel, linux-kernel
Some designs implement reset GPIO via a GPIO expander connected to a
peripheral bus. One such example would be i.MX7 Sabre board where said
GPIO is provided by SPI shift register connected to a bitbanged SPI
bus. In order to support such designs allow reset GPIO request to defer
probing of the driver.
Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
drivers/pci/dwc/pci-imx6.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index e0c36d6..64de9bb 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -595,8 +595,8 @@ static struct dw_pcie_host_ops imx6_pcie_host_ops = {
.host_init = imx6_pcie_host_init,
};
-static int __init imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
- struct platform_device *pdev)
+static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
+ struct platform_device *pdev)
{
struct dw_pcie *pci = imx6_pcie->pci;
struct pcie_port *pp = &pci->pp;
@@ -636,7 +636,7 @@ static const struct dw_pcie_ops dw_pcie_ops = {
.link_up = imx6_pcie_link_up,
};
-static int __init imx6_pcie_probe(struct platform_device *pdev)
+static int imx6_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct dw_pcie *pci;
@@ -660,10 +660,6 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
imx6_pcie->variant =
(enum imx6_pcie_variants)of_device_get_match_data(dev);
- /* Added for PCI abort handling */
- hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
- "imprecise external abort");
-
dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pci->dbi_base = devm_ioremap_resource(dev, dbi_base);
if (IS_ERR(pci->dbi_base))
@@ -683,6 +679,8 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
dev_err(dev, "unable to get reset gpio\n");
return ret;
}
+ } else if (imx6_pcie->reset_gpio == -EPROBE_DEFER) {
+ return imx6_pcie->reset_gpio;
}
/* Fetch clocks */
@@ -796,11 +794,22 @@ static struct platform_driver imx6_pcie_driver = {
.name = "imx6q-pcie",
.of_match_table = imx6_pcie_of_match,
},
+ .probe = imx6_pcie_probe,
.shutdown = imx6_pcie_shutdown,
};
static int __init imx6_pcie_init(void)
{
- return platform_driver_probe(&imx6_pcie_driver, imx6_pcie_probe);
+ /*
+ * Since probe() can be deferred we need to make sure that
+ * hook_fault_code is not called after __init memory is freed
+ * by kernel and since imx6q_pcie_abort_handler() is a no-op
+ * we can install the handler here without risking it
+ * accessing some unitialized driver state
+ */
+ hook_fault_code(16 + 6, imx6q_pcie_abort_handler, SIGBUS, 0,
+ "imprecise external abort");
+
+ return platform_driver_register(&imx6_pcie_driver);
}
device_initcall(imx6_pcie_init);
--
2.9.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v8 3/4] PCI: imx6: Do not wait for speed change on i.MX7
2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 1/4] PCI: imx6: Add code to support i.MX7D Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 2/4] PCI: imx6: Allow probe deferal by reset GPIO Andrey Smirnov
@ 2017-03-28 15:42 ` Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 4/4] PCI: imx6: Do not switch speed if Gen2 is disabled Andrey Smirnov
2017-04-04 22:59 ` [PATCH v8 0/4] i.MX7 PCI support Bjorn Helgaas
4 siblings, 0 replies; 6+ messages in thread
From: Andrey Smirnov @ 2017-03-28 15:42 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Andrey Smirnov, yurovsky, Lucas Stach, Fabio Estevam,
Dong Aisheng, linux-pci, linux-arm-kernel, linux-kernel
As can be seen from [1]:
"...the different behavior between iMX6Q PCIe and iMX7D PCIe maybe
caused by the different controller version.
Regarding to the DOC description, the DIRECT_SPEED_CHANGE should be
cleared after the speed change from GEN1 to GEN2. Unfortunately, when
GEN1 device is used, the behavior is not documented.
So, IC design guys run the simulation and
find out the following behaviors:
1. DIRECT_SPEED_CHANGE will be cleared in 7D after speed change
from GEN1 to GEN2. This matches doc’s description
2. set MAX link speed(PCIE_CAP_TARGET_LINK_SPEED=0x01) as GEN1 and
re-run the simulation, DIRECT_SPEED_CHANGE will not be cleared;
remain as 1, this matches your result, but function test is
passed, so this bit should not affect the normal PCIe function.
..."
imx6_pcie_wait_for_speed_change will report false failures for Gen1 ->
Gen1 speed transition, so avoid doing that check and just rely on
imx6_pcie_wait_for_link only.
[1] https://community.nxp.com/message/867943
Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
drivers/pci/dwc/pci-imx6.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 64de9bb..c731e41 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -545,10 +545,21 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
tmp |= PORT_LOGIC_SPEED_CHANGE;
dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
- ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
- if (ret) {
- dev_err(dev, "Failed to bring link up!\n");
- goto err_reset_phy;
+ if (imx6_pcie->variant != IMX7D) {
+ /*
+ * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
+ * from i.MX6 family when no link speed transition
+ * occurs and we go Gen1 -> yep, Gen1. The difference
+ * is that, in such case, it will not be cleared by HW
+ * which will cause the following code to report false
+ * failure.
+ */
+
+ ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
+ if (ret) {
+ dev_err(dev, "Failed to bring link up!\n");
+ goto err_reset_phy;
+ }
}
/* Make sure link training is finished as well! */
--
2.9.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v8 4/4] PCI: imx6: Do not switch speed if Gen2 is disabled
2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
` (2 preceding siblings ...)
2017-03-28 15:42 ` [PATCH v8 3/4] PCI: imx6: Do not wait for speed change on i.MX7 Andrey Smirnov
@ 2017-03-28 15:42 ` Andrey Smirnov
2017-04-04 22:59 ` [PATCH v8 0/4] i.MX7 PCI support Bjorn Helgaas
4 siblings, 0 replies; 6+ messages in thread
From: Andrey Smirnov @ 2017-03-28 15:42 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Andrey Smirnov, yurovsky, Lucas Stach, Fabio Estevam,
Dong Aisheng, linux-pci, linux-arm-kernel, linux-kernel
Save a bit of time and avoid going through link speed change procedure
in configuration where link max speed is limited to Gen1 in DT.
Cc: yurovsky@gmail.com
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
drivers/pci/dwc/pci-imx6.c | 52 +++++++++++++++++++++++-----------------------
1 file changed, 26 insertions(+), 26 deletions(-)
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index c731e41..9407c03 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -533,40 +533,40 @@ static int imx6_pcie_establish_link(struct imx6_pcie *imx6_pcie)
tmp &= ~PCIE_RC_LCR_MAX_LINK_SPEEDS_MASK;
tmp |= PCIE_RC_LCR_MAX_LINK_SPEEDS_GEN2;
dw_pcie_writel_dbi(pci, PCIE_RC_LCR, tmp);
- } else {
- dev_info(dev, "Link: Gen2 disabled\n");
- }
-
- /*
- * Start Directed Speed Change so the best possible speed both link
- * partners support can be negotiated.
- */
- tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
- tmp |= PORT_LOGIC_SPEED_CHANGE;
- dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
- if (imx6_pcie->variant != IMX7D) {
/*
- * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
- * from i.MX6 family when no link speed transition
- * occurs and we go Gen1 -> yep, Gen1. The difference
- * is that, in such case, it will not be cleared by HW
- * which will cause the following code to report false
- * failure.
+ * Start Directed Speed Change so the best possible
+ * speed both link partners support can be negotiated.
*/
+ tmp = dw_pcie_readl_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL);
+ tmp |= PORT_LOGIC_SPEED_CHANGE;
+ dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, tmp);
+
+ if (imx6_pcie->variant != IMX7D) {
+ /*
+ * On i.MX7, DIRECT_SPEED_CHANGE behaves differently
+ * from i.MX6 family when no link speed transition
+ * occurs and we go Gen1 -> yep, Gen1. The difference
+ * is that, in such case, it will not be cleared by HW
+ * which will cause the following code to report false
+ * failure.
+ */
+
+ ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
+ if (ret) {
+ dev_err(dev, "Failed to bring link up!\n");
+ goto err_reset_phy;
+ }
+ }
- ret = imx6_pcie_wait_for_speed_change(imx6_pcie);
+ /* Make sure link training is finished as well! */
+ ret = imx6_pcie_wait_for_link(imx6_pcie);
if (ret) {
dev_err(dev, "Failed to bring link up!\n");
goto err_reset_phy;
}
- }
-
- /* Make sure link training is finished as well! */
- ret = imx6_pcie_wait_for_link(imx6_pcie);
- if (ret) {
- dev_err(dev, "Failed to bring link up!\n");
- goto err_reset_phy;
+ } else {
+ dev_info(dev, "Link: Gen2 disabled\n");
}
tmp = dw_pcie_readl_dbi(pci, PCIE_RC_LCSR);
--
2.9.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v8 0/4] i.MX7 PCI support
2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
` (3 preceding siblings ...)
2017-03-28 15:42 ` [PATCH v8 4/4] PCI: imx6: Do not switch speed if Gen2 is disabled Andrey Smirnov
@ 2017-04-04 22:59 ` Bjorn Helgaas
4 siblings, 0 replies; 6+ messages in thread
From: Bjorn Helgaas @ 2017-04-04 22:59 UTC (permalink / raw)
To: Andrey Smirnov
Cc: Bjorn Helgaas, Dong Aisheng, linux-pci, linux-kernel,
Rob Herring, Fabio Estevam, yurovsky, linux-arm-kernel,
Lucas Stach
On Tue, Mar 28, 2017 at 08:42:48AM -0700, Andrey Smirnov wrote:
> Hello, everyone:
>
> This is a eightth iteration of the code that adds PCI-subsystem bits
> necessary for enabling PCI support on i.MX7.
>
> NOTE: To test this patchset with real i.MX7 hardware, additional
> patches, that are being upstreamed via different trees, are needed. Full
> working tree is availible at:
>
> https://github.com/ndreys/linux/tree/imx7d/pcie-support-v8
>
> Changes since v7 (can be found at [version7]):
>
> - Collected Reviewed-by for the whole series from Lucas
>
> Changes since v6 (can be found at [version6]):
>
> - Rebased against latest changes in 'next' of PCI subsystem
> git tree
>
> Chagnes since v5 (can be found at [version5]):
>
> - Collected ACKs from Lee and Rob
>
> Changes since v4 (can be found at [version4]):
>
> - Dropped typo-fix patch (originally patch #1 of the
> series).
>
> - Added patch with workaround to address speed change false
> failures (I kept it as a separate patch to better document
> exchange with NXP/Freescale that lead to that patch)
>
> - Added patch to avoid speed change on links configured Gen1
> only (Let me know if that is a terrible idea)
>
> - Addressed section mismatch problem by moving call to
> hook_fault_code to happend before driver registration.
>
> Changes since v3 (can be found at [version3]):
> - Move all of the reset_control_assert's into imx6_pcie_assert_core_reset
> - Documented required reset and power domain DT bindings
>
> Changes since v2 (can be found at [version2]):
>
> - Collected Reviewed-by for patch #2 from Lucas
> - Reset logic implementation moved out into a reset controller
> driver (see [reset1])
> - Removed unused leftover code
>
> Changes since v1 (can be found at [version1]):
>
> - All GPC related code moved into a separate driver (see [gpc1])
> - Removed GPIO probe deferral logging
> - Fixed section mismatch warning
> - Minor reformatting of fsl,imx6q-pcie.txt(as per Rob
> Herring's request)
>
> [version7] https://lkml.org/lkml/2017/3/21/331
> [version6] https://lkml.org/lkml/2017/3/14/584
> [version5] https://lkml.org/lkml/2017/2/20/376
> [version4] https://lkml.org/lkml/2017/2/7/478
> [version3] https://lkml.org/lkml/2017/2/6/565
> [version2] https://lkml.org/lkml/2017/2/1/510
> [version1] https://lkml.org/lkml/2017/1/19/488
> [gpc1] https://lkml.org/lkml/2017/2/6/551
> [reset1] https://lkml.org/lkml/2017/2/6/554
>
> Andrey Smirnov (4):
> PCI: imx6: Add code to support i.MX7D
> PCI: imx6: Allow probe deferal by reset GPIO
> PCI: imx6: Do not wait for speed change on i.MX7
> PCI: imx6: Do not switch speed if Gen2 is disabled
>
> .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 13 +-
> drivers/pci/dwc/pci-imx6.c | 198 +++++++++++++++------
> include/linux/mfd/syscon/imx7-iomuxc-gpr.h | 4 +
> 3 files changed, 160 insertions(+), 55 deletions(-)
Applied to pci/host-imx6 for v4.12, thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-04-04 22:59 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-03-28 15:42 [PATCH v8 0/4] i.MX7 PCI support Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 1/4] PCI: imx6: Add code to support i.MX7D Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 2/4] PCI: imx6: Allow probe deferal by reset GPIO Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 3/4] PCI: imx6: Do not wait for speed change on i.MX7 Andrey Smirnov
2017-03-28 15:42 ` [PATCH v8 4/4] PCI: imx6: Do not switch speed if Gen2 is disabled Andrey Smirnov
2017-04-04 22:59 ` [PATCH v8 0/4] i.MX7 PCI support Bjorn Helgaas
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