1414
1515//! PWM access under Linux using the PWM sysfs interface
1616
17- use std:: io:: prelude:: * ;
18- use std:: fs:: File ;
1917use std:: fs;
18+ use std:: fs:: File ;
2019use std:: fs:: OpenOptions ;
20+ use std:: io:: prelude:: * ;
2121use std:: str:: FromStr ;
2222
2323mod error;
@@ -44,15 +44,19 @@ pub type Result<T> = ::std::result::Result<T, error::Error>;
4444
4545/// Open the specified entry name as a writable file
4646fn pwm_file_wo ( chip : & PwmChip , pin : u32 , name : & str ) -> Result < File > {
47- let f = OpenOptions :: new ( )
48- . write ( true )
49- . open ( format ! ( "/sys/class/pwm/pwmchip{}/pwm{}/{}" , chip. number, pin, name) ) ?;
47+ let f = OpenOptions :: new ( ) . write ( true ) . open ( format ! (
48+ "/sys/class/pwm/pwmchip{}/pwm{}/{}" ,
49+ chip. number, pin, name
50+ ) ) ?;
5051 Ok ( f)
5152}
5253
5354/// Open the specified entry name as a readable file
5455fn pwm_file_ro ( chip : & PwmChip , pin : u32 , name : & str ) -> Result < File > {
55- let f = File :: open ( format ! ( "/sys/class/pwm/pwmchip{}/pwm{}/{}" , chip. number, pin, name) ) ?;
56+ let f = File :: open ( format ! (
57+ "/sys/class/pwm/pwmchip{}/pwm{}/{}" ,
58+ chip. number, pin, name
59+ ) ) ?;
5660 Ok ( f)
5761}
5862
@@ -63,11 +67,13 @@ fn pwm_file_parse<T: FromStr>(chip: &PwmChip, pin: u32, name: &str) -> Result<T>
6367 f. read_to_string ( & mut s) ?;
6468 match s. trim ( ) . parse :: < T > ( ) {
6569 Ok ( r) => Ok ( r) ,
66- Err ( _) => Err ( Error :: Unexpected ( format ! ( "Unexpeted value file contents: {:?}" , s) ) ) ,
70+ Err ( _) => Err ( Error :: Unexpected ( format ! (
71+ "Unexpeted value file contents: {:?}" ,
72+ s
73+ ) ) ) ,
6774 }
6875}
6976
70-
7177impl PwmChip {
7278 pub fn new ( number : u32 ) -> Result < PwmChip > {
7379 fs:: metadata ( & format ! ( "/sys/class/pwm/pwmchip{}" , number) ) ?;
@@ -81,13 +87,21 @@ impl PwmChip {
8187 npwm_file. read_to_string ( & mut s) ?;
8288 match s. parse :: < u32 > ( ) {
8389 Ok ( n) => Ok ( n) ,
84- Err ( _) => Err ( Error :: Unexpected ( format ! ( "Unexpected npwm contents: {:?}" , s) ) ) ,
90+ Err ( _) => Err ( Error :: Unexpected ( format ! (
91+ "Unexpected npwm contents: {:?}" ,
92+ s
93+ ) ) ) ,
8594 }
8695 }
8796
8897 pub fn export ( & self , number : u32 ) -> Result < ( ) > {
8998 // only export if not already exported
90- if fs:: metadata ( & format ! ( "/sys/class/pwm/pwmchip{}/pwm{}" , self . number, number) ) . is_err ( ) {
99+ if fs:: metadata ( & format ! (
100+ "/sys/class/pwm/pwmchip{}/pwm{}" ,
101+ self . number, number
102+ ) )
103+ . is_err ( )
104+ {
91105 let path = format ! ( "/sys/class/pwm/pwmchip{}/export" , self . number) ;
92106 let mut export_file = File :: create ( & path) ?;
93107 let _ = export_file. write_all ( format ! ( "{}" , number) . as_bytes ( ) ) ;
@@ -96,7 +110,12 @@ impl PwmChip {
96110 }
97111
98112 pub fn unexport ( & self , number : u32 ) -> Result < ( ) > {
99- if fs:: metadata ( & format ! ( "/sys/class/pwm/pwmchip{}/pwm{}" , self . number, number) ) . is_ok ( ) {
113+ if fs:: metadata ( & format ! (
114+ "/sys/class/pwm/pwmchip{}/pwm{}" ,
115+ self . number, number
116+ ) )
117+ . is_ok ( )
118+ {
100119 let path = format ! ( "/sys/class/pwm/pwmchip{}/unexport" , self . number) ;
101120 let mut export_file = File :: create ( & path) ?;
102121 let _ = export_file. write_all ( format ! ( "{}" , number) . as_bytes ( ) ) ;
@@ -112,15 +131,16 @@ impl Pwm {
112131 pub fn new ( chip : u32 , number : u32 ) -> Result < Pwm > {
113132 let chip: PwmChip = PwmChip :: new ( chip) ?;
114133 Ok ( Pwm {
115- chip : chip,
116- number : number,
117- } )
134+ chip : chip,
135+ number : number,
136+ } )
118137 }
119138
120139 /// Run a closure with the GPIO exported
121140 #[ inline]
122141 pub fn with_exported < F > ( & self , closure : F ) -> Result < ( ) >
123- where F : FnOnce ( ) -> Result < ( ) >
142+ where
143+ F : FnOnce ( ) -> Result < ( ) > ,
124144 {
125145 self . export ( ) ?;
126146 match closure ( ) {
@@ -152,7 +172,7 @@ impl Pwm {
152172 match enable_state {
153173 1 => true ,
154174 0 => false ,
155- _ => panic ! ( "enable != 1|0 should be unreachable" )
175+ _ => panic ! ( "enable != 1|0 should be unreachable" ) ,
156176 }
157177 } )
158178 }
@@ -168,8 +188,7 @@ impl Pwm {
168188 pub fn set_duty_cycle_ns ( & self , duty_cycle_ns : u32 ) -> Result < ( ) > {
169189 // we'll just let the kernel do the validation
170190 let mut duty_cycle_file = pwm_file_wo ( & self . chip , self . number , "duty_cycle" ) ?;
171- duty_cycle_file
172- . write_all ( format ! ( "{}" , duty_cycle_ns) . as_bytes ( ) ) ?;
191+ duty_cycle_file. write_all ( format ! ( "{}" , duty_cycle_ns) . as_bytes ( ) ) ?;
173192 Ok ( ( ) )
174193 }
175194
@@ -181,8 +200,7 @@ impl Pwm {
181200 /// The period of the PWM signal in Nanoseconds
182201 pub fn set_period_ns ( & self , period_ns : u32 ) -> Result < ( ) > {
183202 let mut period_file = pwm_file_wo ( & self . chip , self . number , "period" ) ?;
184- period_file
185- . write_all ( format ! ( "{}" , period_ns) . as_bytes ( ) ) ?;
203+ period_file. write_all ( format ! ( "{}" , period_ns) . as_bytes ( ) ) ?;
186204 Ok ( ( ) )
187205 }
188206}
0 commit comments