How to get a Y-axis to each separate graph with facet_grid? (with Reprex)

[HugoSantarem]

I am plotting a graph using ggplot2 and I'd like to have a Y-axis to each separate graph. I get the Y-axis for every graph when I use facet_wrap, but the layout is not what I want. On the other hand, facet_grid outputs the exact layout I am looking for, but I can't get the separate Y-axis in each graph.

How can I have the the same layout from facet_grid but also a Y-axis for each graph as in facet_wrap?

Here's a simple reproducible example.
Thank you for the input.

# Pkgs
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library(ggplot2)

# Generate fake data
set.seed(125)
df = data.frame(
  year = c(rep(2017, 3), rep(2018, 3), rep(2019, 3)),
  type = rep(c("A", "B", "C"), 3),
  month = rep(c("Jan", "Feb", "Mar"), 3),
  signal = sample(x = seq(100, 2500, 100), size = 9)
) %>%
  mutate(month = factor(month, levels = c("Jan", "Feb", "Mar")))


#Wrapping use facet_wrap........................................

# When I use facet_wrap, I get a Y-axis for each separate graph,
# but then I have a "two-level title" for each  graph, 
# consisting of year and type. 

df %>%
  ggplot(aes(x = month, y = signal)) +
  geom_point() +
  facet_wrap(vars(year, type), scales = "free")

#Wrapping use facet_grid.........................................

# When I use facet_grid, I get a Y-axis for an entire row, and 
# this is not what I want. However, the layout is exactly what I want.


df %>%
  ggplot(aes(x = month, y = signal)) +
  geom_point() +
  facet_grid(rows = vars(type),
             cols = vars(year),
             scales = "free")

^{Created on 2021-02-17 by the reprex package (v1.0.0)}

[martin.R]

The simple answer is that you cannot have the layout you want using facet_grid().

A far more complicated answer could involve generating sub-plots and stitching them together via e.g. grid.arrange() or the patchwork package.

This might help:
Modifying facet scales in ggplot2 | Fish & Whistle (fishandwhistle.net)

[HugoSantarem]

Thanks for the link, Martin.R. I'll look into it.