First, some facts about Spanish:
There are two "r" phonemes, /ɾ/ and /r/. Word internally between vowels, they contrast, like "caro" [kaɾo] vs. "carro" [karo]. But word initially, only [r] appears, "religión" [relixjón], and word-finally the tap [ɾ] is favored, but the trill [r] could occur. [tɾabajaɾ] ~ [tɾabajar].
Crucially, however, when word final but followed by a vowel, only the [ɾ] occurs: trabajar en casa [tɾabajaɾ en..] vs. *[tɾabajar en..]
In Portuguese, there are also two "r phonemes", the tap [ɾ] and one of many different realizations of the trill phoneme (let's call it /R/), it can be a uvular trill, a voiceless velar fricative, a glottal fricative, an alveolar trill like in Spanish, or, I'm told, an approximant r like English.
The facts are a little different than Spanish:
Word initially, only /R/ occurs, "religão" [Religaw], it also occurs syllable final "barco" [baRku]. (at least in Brazilian Portuguese--can this be confirmed in EP?) Word internally between vowels, they contrast, same as in Spanish.
What does Portuguese do word finally, and before vowels? What are your pronunciations for the following? Is the orthographic "r" pronounced as [ɾ] or [R] ([x], [h], [r], [ʁ], etc.) for you? And where are you from?