| Message ID | 1525360119-102166-3-git-send-email-john.garry@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | HISI LPC ACPI UART support | expand |
On Thu, 2018-05-03 at 23:08 +0800, John Garry wrote: > On the Huawei D03 development board the system UART is > the UART connected on the LPC bus. > > The profile for the device driver required for this HW > would be as follows: > - platform driver > - supports 16550 > - supports ACPI > - supports polling mode > - supports IO space > > In principle we should use the PNP driver (8250_dw.c) for > 8250-devices with ACPI FW. However since this host driver > does not support PNP devices, and modifying the PNP core > code to support it is not worth the effort, use the generic > 8250 isa driver. > > For this, we need to setup the MFD cell platform data for > a serial 8250 Port. > > In addition to this change, we also make the following > changes: > - set child ACPI device as enumerated. This fixes a conflict > in serdev setup for the UART > - use platform device ID auto for creating the uart child > platform device to avoid conflict with platform devices > created for serial8250_isa_devs from 8250_core.c > + mfd_cell->platform_data = devm_kmemdup(hostdev, &ref_port, > + sizeof(ref_port), > GFP_KERNEL); Isn't this done by MFD core? -- Andy Shevchenko <andriy.shevchenko@linux.intel.com> Intel Finland Oy
On 03/05/2018 17:56, Andy Shevchenko wrote: > On Thu, 2018-05-03 at 23:08 +0800, John Garry wrote: >> On the Huawei D03 development board the system UART is >> the UART connected on the LPC bus. >> >> The profile for the device driver required for this HW >> would be as follows: >> - platform driver >> - supports 16550 >> - supports ACPI >> - supports polling mode >> - supports IO space >> >> In principle we should use the PNP driver (8250_dw.c) for >> 8250-devices with ACPI FW. However since this host driver >> does not support PNP devices, and modifying the PNP core >> code to support it is not worth the effort, use the generic >> 8250 isa driver. >> >> For this, we need to setup the MFD cell platform data for >> a serial 8250 Port. >> >> In addition to this change, we also make the following >> changes: >> - set child ACPI device as enumerated. This fixes a conflict >> in serdev setup for the UART >> - use platform device ID auto for creating the uart child >> platform device to avoid conflict with platform devices >> created for serial8250_isa_devs from 8250_core.c > Hi Andy, >> + mfd_cell->platform_data = devm_kmemdup(hostdev, &ref_port, >> + sizeof(ref_port), >> GFP_KERNEL); > > Isn't this done by MFD core? It does, but what we are copying from is on the stack and could be overwritten by the point we call the mfd_add_devices(). But this could be improved. BTW, As seen in other discussion, future of MFD usage is in doubt, so all this may be dropped. Thanks very much, John > >
diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 71693d77..b0ee2fa 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -17,6 +17,7 @@ #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/pci.h> +#include <linux/serial_8250.h> #include <linux/slab.h> #define DRV_NAME "hisi-lpc" @@ -362,6 +363,35 @@ static int hisi_lpc_acpi_xlat_io_res(struct acpi_device *adev, .pnpid = "IPI0001", }; +static const struct mfd_cell_acpi_match hisi_lpc_acpi_mfd_match_uart = { + .pnpid = "HISI1031", +}; + +static int hisi_lpc_acpi_uart_setup(struct device *hostdev, + struct mfd_cell *mfd_cell) +{ + const struct resource * const resource = mfd_cell->resources; + struct plat_serial8250_port ref_port[] = { + { + .iobase = resource->start, + .uartclk = 1843200, + .iotype = UPIO_PORT, + .flags = UPF_BOOT_AUTOCONF, + }, + {} + }; + + mfd_cell->platform_data = devm_kmemdup(hostdev, &ref_port, + sizeof(ref_port), GFP_KERNEL); + if (!mfd_cell->platform_data) + return -ENOMEM; + + mfd_cell->pdata_size = sizeof(ref_port); + + return 0; +} + + struct hisi_lpc_acpi_mfd_cell { struct mfd_cell mfd_cell; int (*setup)(struct device *hostdev, struct mfd_cell *mfd_cell); @@ -373,6 +403,14 @@ struct hisi_lpc_acpi_mfd_cell { .acpi_match = &hisi_lpc_acpi_mfd_match_ipmi, }, }, + /* 8250-compatible uart */ + { + .mfd_cell = { + .name = "serial8250", + .acpi_match = &hisi_lpc_acpi_mfd_match_uart, + }, + .setup = hisi_lpc_acpi_uart_setup, + }, {} }; @@ -530,10 +568,11 @@ static int hisi_lpc_acpi_probe(struct device *hostdev) return ret; } + acpi_device_set_enumerated(child); count++; } - ret = mfd_add_devices(hostdev, PLATFORM_DEVID_NONE, + ret = mfd_add_devices(hostdev, PLATFORM_DEVID_AUTO, mfd_cells, cell_num, NULL, 0, NULL); if (ret) { dev_err(hostdev, "failed to add mfd cells (%d)\n", ret);
On the Huawei D03 development board the system UART is the UART connected on the LPC bus. The profile for the device driver required for this HW would be as follows: - platform driver - supports 16550 - supports ACPI - supports polling mode - supports IO space In principle we should use the PNP driver (8250_dw.c) for 8250-devices with ACPI FW. However since this host driver does not support PNP devices, and modifying the PNP core code to support it is not worth the effort, use the generic 8250 isa driver. For this, we need to setup the MFD cell platform data for a serial 8250 Port. In addition to this change, we also make the following changes: - set child ACPI device as enumerated. This fixes a conflict in serdev setup for the UART - use platform device ID auto for creating the uart child platform device to avoid conflict with platform devices created for serial8250_isa_devs from 8250_core.c Signed-off-by: John Garry <john.garry@huawei.com> --- drivers/bus/hisi_lpc.c | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) -- 1.9.1