Change in coreboot[master]: drivers/wwan/fm: Add Fibocom 5G WWAN ACPI support

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Bora Guvendik, Anil Kumar K, Cliff Huang, Subrata Banik, Paul Menzel, Thejaswani Putta.
Tim Wawrzynczak has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61354 )

Change subject: drivers/wwan/fm: Add Fibocom 5G WWAN ACPI support
......................................................................

Patch Set 8:

(3 comments)

File src/drivers/wwan/fm/acpi_fm350gl.c:

https://review.coreboot.org/c/coreboot/+/61354/comment/b7567941_aa238297 
PS7, Line 55: acpigen_write_if_lequal_op_int(LOCAL0_OP, 0);
            : 	if (wwan_fm350gl_get_rtd3_method_support(config) | ACPI_PCIE_RP_EMIT_L23)
            : 		acpigen_emit_namestring(acpi_device_path_join(parent_dev, "DL23"));
            : 	/* assert PERST# pin */
            : 	acpigen_enable_tx_gpio(&config->perst_gpio);
Sorry am I misreading the logic here?

I am reading this as:
If PERST# is low, run the DL23() Method and then drive PERST# low? even though the TX state already was read back as low?

https://review.coreboot.org/c/coreboot/+/61354/comment/3e09a204_33905000 
PS7, Line 64: /* warm reset */
            : 	acpigen_write_if_lequal_op_int(ARG0_OP, 0);
            : 	acpigen_write_sleep(FM350GL_TBTG);
            : 	/* cold reset */
            : 	acpigen_write_else();
            : 	acpigen_write_if_lequal_op_int(ARG0_OP, 1);
suggestion:
add some macros here like
```
enum reset_type {
      RESET_TYPE_WARM = 0,
      RESET_TYPE_COLD = 1,
};
```

and then you can use those directly here

https://review.coreboot.org/c/coreboot/+/61354/comment/76b26178_720e3878 
PS7, Line 52: acpigen_write_method_serialized("FHRF", 1);
            : 	/* LOCAL0 = PERST# */
            : 	acpigen_get_tx_gpio(&config->perst_gpio);
            : 	acpigen_write_if_lequal_op_int(LOCAL0_OP, 0);
            : 	if (wwan_fm350gl_get_rtd3_method_support(config) | ACPI_PCIE_RP_EMIT_L23)
            : 		acpigen_emit_namestring(acpi_device_path_join(parent_dev, "DL23"));
            : 	/* assert PERST# pin */
            : 	acpigen_enable_tx_gpio(&config->perst_gpio);
            : 	acpigen_write_if_end(); /* If */
            : 	acpigen_write_sleep(FM350GL_TR2B);
            : 	/* assert RESET# pin */
            : 	acpigen_enable_tx_gpio(&config->reset_gpio);
            : 	/* warm reset */
            : 	acpigen_write_if_lequal_op_int(ARG0_OP, 0);
            : 	acpigen_write_sleep(FM350GL_TBTG);
            : 	/* cold reset */
            : 	acpigen_write_else();
            : 	acpigen_write_if_lequal_op_int(ARG0_OP, 1);
            : 	/* disable source clock */
            : 	if (wwan_fm350gl_get_rtd3_method_support(config) | ACPI_PCIE_RP_EMIT_SRCK)
            : 		acpigen_emit_namestring(acpi_device_path_join(parent_dev, "SRCK"));
            : 	acpigen_emit_byte(ZERO_OP);
            : 	acpigen_write_sleep(FM350GL_TB2F);
            : 	/* assert FCPO# pin */
            : 	acpigen_enable_tx_gpio(&config->fcpo_gpio);
            : 	acpigen_write_sleep(FM350GL_TFDI);
            : 	acpigen_write_if_end(); /* If */
            : 	acpigen_pop_len(); /* Else */
            : 	acpigen_write_method_end(); /* Method */
            : }
suggestion:
To make the If scopes and nesting read more like C, we can use arbitrary nested scopes in the actual C code to make it read similarly, e.g.

```
{
    acpigen_write_method_serialized("FHRF", 1);
    /* LOCAL0 = PERST# */
    acpigen_get_tx_gpio(&config->perst_gpio);
    acpigen_write_if_lequal_op_int(LOCAL0_OP, 0);
    {
    	if (wwan_fm350gl_get_rtd3_method_support(config) | ACPI_PCIE_RP_EMIT_L23)
    		acpigen_emit_namestring(acpi_device_path_join(parent_dev, "DL23"));
    
    	/* assert PERST# pin */
    	acpigen_enable_tx_gpio(&config->perst_gpio);
    }
    acpigen_write_if_end(); /* If */
    
    acpigen_write_sleep(FM350GL_TR2B);
    
    /* assert RESET# pin */
    acpigen_enable_tx_gpio(&config->reset_gpio);
    
    acpigen_write_if_lequal_op_int(ARG0_OP, RESET_TYPE_WARM);
    {
    	acpigen_write_sleep(FM350GL_TBTG);
    }
    acpigen_write_else();
    {
    	acpigen_write_if_lequal_op_int(ARG0_OP, RESET_TYPE_COLD);
    	{
    		/* disable source clock */
    		if (wwan_fm350gl_get_rtd3_method_support(config) | ACPI_PCIE_RP_EMIT_SRCK)
    			acpigen_emit_namestring(acpi_device_path_join(parent_dev, "SRCK"));
    		acpigen_emit_byte(ZERO_OP);
    		acpigen_write_sleep(FM350GL_TB2F);
    		/* assert FCPO# pin */
    		acpigen_enable_tx_gpio(&config->fcpo_gpio);
    		acpigen_write_sleep(FM350GL_TFDI);
    	}
    	acpigen_write_if_end(); /* If */
    }
    acpigen_pop_len(); /* Else */

acpigen_write_method_end(); /* Method */
}

```