| Message ID | 1452667666-17533-4-git-send-email-kishon@ti.com |
|---|---|
| State | New |
| Headers | show |
Hi Suman, On Wednesday 13 January 2016 11:21 PM, Suman Anna wrote: > On 01/13/2016 12:47 AM, Kishon Vijay Abraham I wrote: >> Use platform populated reset assert and deassert >> callbacks to perform reset of PCIe. >> >> Use these callbacks until a reset interface using drivers/reset >> is available for the purpose. >> >> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> >> Signed-off-by: Sekhar Nori <nsekhar@ti.com> >> --- >> drivers/pci/host/pci-dra7xx.c | 32 ++++++++++++++++++++++++++++++++ >> 1 file changed, 32 insertions(+) >> >> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c >> index 8c36880..049083d 100644 >> --- a/drivers/pci/host/pci-dra7xx.c >> +++ b/drivers/pci/host/pci-dra7xx.c >> @@ -25,6 +25,8 @@ >> #include <linux/resource.h> >> #include <linux/types.h> >> >> +#include <linux/platform_data/pci-dra7xx.h> >> + >> #include "pcie-designware.h" >> >> /* PCIe controller wrapper DRA7XX configuration registers */ >> @@ -329,6 +331,32 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, >> return 0; >> } >> >> +static int dra7xx_pcie_reset(struct platform_device *pdev) >> +{ >> + int ret; >> + struct device *dev = &pdev->dev; >> + struct pci_dra7xx_platform_data *pdata = pdev->dev.platform_data; >> + >> + if (!(pdata && pdata->deassert_reset && pdata->assert_reset)) { >> + dev_err(dev, "platform data for reset not found!\n"); >> + return -EINVAL; >> + } >> + >> + ret = pdata->assert_reset(pdev, pdata->reset_name); >> + if (ret) { >> + dev_err(dev, "assert_reset failed: %d\n", ret); >> + return ret; >> + } >> + >> + ret = pdata->deassert_reset(pdev, pdata->reset_name); >> + if (ret) { >> + dev_err(dev, "deassert_reset failed: %d\n", ret); >> + return ret; >> + } > > The only comment I have on this is the symmetry (assert_reset invocation > in driver remove). If you install and remove the module once, then the > reset stays deasserted. On Power-On-Reset, the resets by default will be > in asserted state. hmm.. not sure of the benefits of leaving the reset lines de-asserted during remove. The idea is irrespective of the initial sate or power-on state, during probe the driver should assert and de-assert the reset lines. Thanks Kishon
diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c index 8c36880..049083d 100644 --- a/drivers/pci/host/pci-dra7xx.c +++ b/drivers/pci/host/pci-dra7xx.c @@ -25,6 +25,8 @@ #include <linux/resource.h> #include <linux/types.h> +#include <linux/platform_data/pci-dra7xx.h> + #include "pcie-designware.h" /* PCIe controller wrapper DRA7XX configuration registers */ @@ -329,6 +331,32 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx, return 0; } +static int dra7xx_pcie_reset(struct platform_device *pdev) +{ + int ret; + struct device *dev = &pdev->dev; + struct pci_dra7xx_platform_data *pdata = pdev->dev.platform_data; + + if (!(pdata && pdata->deassert_reset && pdata->assert_reset)) { + dev_err(dev, "platform data for reset not found!\n"); + return -EINVAL; + } + + ret = pdata->assert_reset(pdev, pdata->reset_name); + if (ret) { + dev_err(dev, "assert_reset failed: %d\n", ret); + return ret; + } + + ret = pdata->deassert_reset(pdev, pdata->reset_name); + if (ret) { + dev_err(dev, "deassert_reset failed: %d\n", ret); + return ret; + } + + return 0; +} + static int __init dra7xx_pcie_probe(struct platform_device *pdev) { u32 reg; @@ -347,6 +375,10 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) enum of_gpio_flags flags; unsigned long gpio_flags; + ret = dra7xx_pcie_reset(pdev); + if (ret) + return ret; + dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL); if (!dra7xx) return -ENOMEM;