diff options
Diffstat (limited to '0014-mfd-intel-lpss-Pass-SDA-hold-time-to-I2C-host-contro.patch')
| -rw-r--r-- | 0014-mfd-intel-lpss-Pass-SDA-hold-time-to-I2C-host-contro.patch | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/0014-mfd-intel-lpss-Pass-SDA-hold-time-to-I2C-host-contro.patch b/0014-mfd-intel-lpss-Pass-SDA-hold-time-to-I2C-host-contro.patch new file mode 100644 index 000000000..c06105162 --- /dev/null +++ b/0014-mfd-intel-lpss-Pass-SDA-hold-time-to-I2C-host-contro.patch @@ -0,0 +1,138 @@ +From 028af5941dd870afd5eb6a95c39f25564dcca79a Mon Sep 17 00:00:00 2001 +From: Mika Westerberg <mika.westerberg@linux.intel.com> +Date: Mon, 30 Nov 2015 17:11:42 +0200 +Subject: [PATCH 14/16] mfd: intel-lpss: Pass SDA hold time to I2C host + controller driver + +Intel Skylake the LPSS I2C pad circuit has internal delays that require +programming non-zero SDA hold time for the I2C host controller. If this is +not done communication to slave devices may fail with arbitration lost +errors like the one seen below taken from Lenovo Yoga 900: + + i2c_hid i2c-SYNA2B29:00: Fetching the HID descriptor + i2c_hid i2c-SYNA2B29:00: __i2c_hid_command: cmd=20 00 + i2c_designware i2c_designware.1: i2c_dw_handle_tx_abort: lost arbitration + +To fix this we follow what the Windows driver is doing and pass the default +SDA hold time of 230 ns to all Intel Skylake host controllers. This still +allows the platform to override these values by passing special ACPI +methods SSCN and FMCN. + +Reported-by: Kevin Fenzi <kevin@scrye.com> +Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> +Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> +Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +--- + drivers/mfd/intel-lpss-acpi.c | 19 +++++++++++++++++-- + drivers/mfd/intel-lpss-pci.c | 31 +++++++++++++++++++++++-------- + 2 files changed, 40 insertions(+), 10 deletions(-) + +diff --git a/drivers/mfd/intel-lpss-acpi.c b/drivers/mfd/intel-lpss-acpi.c +index b6fd904..06f00d6 100644 +--- a/drivers/mfd/intel-lpss-acpi.c ++++ b/drivers/mfd/intel-lpss-acpi.c +@@ -18,6 +18,7 @@ + #include <linux/pm.h> + #include <linux/pm_runtime.h> + #include <linux/platform_device.h> ++#include <linux/property.h> + + #include "intel-lpss.h" + +@@ -25,6 +26,20 @@ static const struct intel_lpss_platform_info spt_info = { + .clk_rate = 120000000, + }; + ++static struct property_entry spt_i2c_properties[] = { ++ PROPERTY_ENTRY_U32("i2c-sda-hold-time-ns", 230), ++ { }, ++}; ++ ++static struct property_set spt_i2c_pset = { ++ .properties = spt_i2c_properties, ++}; ++ ++static const struct intel_lpss_platform_info spt_i2c_info = { ++ .clk_rate = 120000000, ++ .pset = &spt_i2c_pset, ++}; ++ + static const struct intel_lpss_platform_info bxt_info = { + .clk_rate = 100000000, + }; +@@ -35,8 +50,8 @@ static const struct intel_lpss_platform_info bxt_i2c_info = { + + static const struct acpi_device_id intel_lpss_acpi_ids[] = { + /* SPT */ +- { "INT3446", (kernel_ulong_t)&spt_info }, +- { "INT3447", (kernel_ulong_t)&spt_info }, ++ { "INT3446", (kernel_ulong_t)&spt_i2c_info }, ++ { "INT3447", (kernel_ulong_t)&spt_i2c_info }, + /* BXT */ + { "80860AAC", (kernel_ulong_t)&bxt_i2c_info }, + { "80860ABC", (kernel_ulong_t)&bxt_info }, +diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c +index 5bfdfcc..a677480 100644 +--- a/drivers/mfd/intel-lpss-pci.c ++++ b/drivers/mfd/intel-lpss-pci.c +@@ -17,6 +17,7 @@ + #include <linux/pci.h> + #include <linux/pm.h> + #include <linux/pm_runtime.h> ++#include <linux/property.h> + + #include "intel-lpss.h" + +@@ -65,6 +66,20 @@ static const struct intel_lpss_platform_info spt_info = { + .clk_rate = 120000000, + }; + ++static struct property_entry spt_i2c_properties[] = { ++ PROPERTY_ENTRY_U32("i2c-sda-hold-time-ns", 230), ++ { }, ++}; ++ ++static struct property_set spt_i2c_pset = { ++ .properties = spt_i2c_properties, ++}; ++ ++static const struct intel_lpss_platform_info spt_i2c_info = { ++ .clk_rate = 120000000, ++ .pset = &spt_i2c_pset, ++}; ++ + static const struct intel_lpss_platform_info spt_uart_info = { + .clk_rate = 120000000, + .clk_con_id = "baudclk", +@@ -121,20 +136,20 @@ static const struct pci_device_id intel_lpss_pci_ids[] = { + { PCI_VDEVICE(INTEL, 0x9d28), (kernel_ulong_t)&spt_uart_info }, + { PCI_VDEVICE(INTEL, 0x9d29), (kernel_ulong_t)&spt_info }, + { PCI_VDEVICE(INTEL, 0x9d2a), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d60), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d61), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d62), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d63), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d64), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0x9d65), (kernel_ulong_t)&spt_info }, ++ { PCI_VDEVICE(INTEL, 0x9d60), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0x9d61), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0x9d62), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0x9d63), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0x9d64), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0x9d65), (kernel_ulong_t)&spt_i2c_info }, + { PCI_VDEVICE(INTEL, 0x9d66), (kernel_ulong_t)&spt_uart_info }, + /* SPT-H */ + { PCI_VDEVICE(INTEL, 0xa127), (kernel_ulong_t)&spt_uart_info }, + { PCI_VDEVICE(INTEL, 0xa128), (kernel_ulong_t)&spt_uart_info }, + { PCI_VDEVICE(INTEL, 0xa129), (kernel_ulong_t)&spt_info }, + { PCI_VDEVICE(INTEL, 0xa12a), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0xa160), (kernel_ulong_t)&spt_info }, +- { PCI_VDEVICE(INTEL, 0xa161), (kernel_ulong_t)&spt_info }, ++ { PCI_VDEVICE(INTEL, 0xa160), (kernel_ulong_t)&spt_i2c_info }, ++ { PCI_VDEVICE(INTEL, 0xa161), (kernel_ulong_t)&spt_i2c_info }, + { PCI_VDEVICE(INTEL, 0xa166), (kernel_ulong_t)&spt_uart_info }, + { } + }; +-- +2.5.0 + |