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mfd: intel-lpss: Fix Intel Cannon Lake LPSS I2C input clock
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Intel Cannon Lake PCH has much higher 216 MHz input clock to LPSS I2C
than Sunrisepoint which uses 120 MHz. Preliminary information was that
both share the same clock rate but actual silicon implements elevated
rate for better support for 3.4 MHz high-speed I2C.

This incorrect input clock rate results too high I2C bus clock in case
ACPI doesn't provide tuned I2C timing parameters since I2C host
controller driver calculates them from input clock rate.

Fix this by using the correct rate. We still share the same 230 ns SDA
hold time value than Sunrisepoint.

Cc: stable@vger.kernel.org
Fixes: b418bbf ("mfd: intel-lpss: Add Intel Cannonlake PCI IDs")
Reported-by: Jian-Hong Pan <jian-hong@endlessm.com>
Reported-by: Chris Chiu <chiu@endlessm.com>
Reported-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Jian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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Jarkko Nikula authored and Lee Jones committed Jun 4, 2018
1 parent 4eb1d7f commit 4e93a65
Showing 1 changed file with 15 additions and 10 deletions.
25 changes: 15 additions & 10 deletions drivers/mfd/intel-lpss-pci.c
Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,11 @@ static const struct intel_lpss_platform_info apl_i2c_info = {
.properties = apl_i2c_properties,
};

static const struct intel_lpss_platform_info cnl_i2c_info = {
.clk_rate = 216000000,
.properties = spt_i2c_properties,
};

static const struct pci_device_id intel_lpss_pci_ids[] = {
/* BXT A-Step */
{ PCI_VDEVICE(INTEL, 0x0aac), (kernel_ulong_t)&bxt_i2c_info },
Expand Down Expand Up @@ -207,13 +212,13 @@ static const struct pci_device_id intel_lpss_pci_ids[] = {
{ PCI_VDEVICE(INTEL, 0x9daa), (kernel_ulong_t)&spt_info },
{ PCI_VDEVICE(INTEL, 0x9dab), (kernel_ulong_t)&spt_info },
{ PCI_VDEVICE(INTEL, 0x9dfb), (kernel_ulong_t)&spt_info },
{ PCI_VDEVICE(INTEL, 0x9dc5), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dc6), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dc5), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dc6), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dc7), (kernel_ulong_t)&spt_uart_info },
{ PCI_VDEVICE(INTEL, 0x9de8), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9de9), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dea), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9deb), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9de8), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9de9), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9dea), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0x9deb), (kernel_ulong_t)&cnl_i2c_info },
/* SPT-H */
{ PCI_VDEVICE(INTEL, 0xa127), (kernel_ulong_t)&spt_uart_info },
{ PCI_VDEVICE(INTEL, 0xa128), (kernel_ulong_t)&spt_uart_info },
Expand All @@ -240,10 +245,10 @@ static const struct pci_device_id intel_lpss_pci_ids[] = {
{ PCI_VDEVICE(INTEL, 0xa32b), (kernel_ulong_t)&spt_info },
{ PCI_VDEVICE(INTEL, 0xa37b), (kernel_ulong_t)&spt_info },
{ PCI_VDEVICE(INTEL, 0xa347), (kernel_ulong_t)&spt_uart_info },
{ PCI_VDEVICE(INTEL, 0xa368), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa369), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa36a), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa36b), (kernel_ulong_t)&spt_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa368), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa369), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa36a), (kernel_ulong_t)&cnl_i2c_info },
{ PCI_VDEVICE(INTEL, 0xa36b), (kernel_ulong_t)&cnl_i2c_info },
{ }
};
MODULE_DEVICE_TABLE(pci, intel_lpss_pci_ids);
Expand Down

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