| Message ID | 20250411131423.3802611-8-guodong@riscstar.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | pwm: Update PWM_PXA driver for SpacemiT K1 | expand |
| Context | Check | Description |
|---|---|---|
| bjorn/pre-ci_am | fail | Failed to apply series |
On 21:14 Fri 11 Apr , Guodong Xu wrote: > Add a PWM-based backlight node for the Banana Pi BPI-F3 board, > using PWM14. The backlight is defined as a 'pwm-backlight' device with > brightness levels and a default brightness setting. PWM14 is assigned > a period length of 2000 nanoseconds. > > This configuration was used to verify PWM driver changes, with PWM14 > tested and its waveform confirmed as correct. > > The node status is set to "disabled", and should be enabled when the > display driver is ready. > .. see comments below > Signed-off-by: Guodong Xu <guodong@riscstar.com> > --- > .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > index 816ef1bc358e..d04b57ddeb46 100644 > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > @@ -28,6 +28,32 @@ led1 { > default-state = "on"; > }; > }; > + > + pwm_bl: lcd_backlight { > + compatible = "pwm-backlight"; > + > + pwms = <&pwm14 2000>; > + brightness-levels = < > + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 > + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 > + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 > + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 > + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 > + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 > + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 > + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 > + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 > + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 > + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 > + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 > + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 > + >; > + default-brightness-level = <100>; > + status = "disabled"; I'm confused, has DT in board file with disabled status doesn't make sense? it doesn't really useful for placeholder, even worse that functionality may not verified, so I'd suggest sending along with display driver while at it.. > + }; > }; > > &uart0 { > @@ -35,3 +61,9 @@ &uart0 { > pinctrl-0 = <&uart0_2_cfg>; > status = "okay"; > }; > + > +&pwm14 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pwm14_1_cfg>; .. > + status = "disabled"; ditto > +}; > -- > 2.43.0 >
On 4/11/25 9:05 AM, Yixun Lan wrote: > > On 21:14 Fri 11 Apr , Guodong Xu wrote: >> Add a PWM-based backlight node for the Banana Pi BPI-F3 board, >> using PWM14. The backlight is defined as a 'pwm-backlight' device with >> brightness levels and a default brightness setting. PWM14 is assigned >> a period length of 2000 nanoseconds. >> >> This configuration was used to verify PWM driver changes, with PWM14 >> tested and its waveform confirmed as correct. >> >> The node status is set to "disabled", and should be enabled when the >> display driver is ready. >> > .. see comments below >> Signed-off-by: Guodong Xu <guodong@riscstar.com> >> --- >> .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ >> 1 file changed, 32 insertions(+) >> >> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts >> index 816ef1bc358e..d04b57ddeb46 100644 >> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts >> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts >> @@ -28,6 +28,32 @@ led1 { >> default-state = "on"; >> }; >> }; >> + >> + pwm_bl: lcd_backlight { >> + compatible = "pwm-backlight"; >> + >> + pwms = <&pwm14 2000>; >> + brightness-levels = < >> + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 >> + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 >> + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 >> + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 >> + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 >> + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 >> + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 >> + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 >> + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 >> + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 >> + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 >> + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 >> + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 >> + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 >> + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 >> + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 >> + >; >> + default-brightness-level = <100>; >> + status = "disabled"; > I'm confused, has DT in board file with disabled status doesn't make sense? > it doesn't really useful for placeholder, even worse that functionality may not > verified, so I'd suggest sending along with display driver while at it.. I think I suggested he include this. Guodong tested PWM using a backlight on a display connected to a Banana Pi PBI-F3 board. The above numbers come directly from the downstream code, which uses this PWM consistently as a display back light. But you're right, the exact set of numbers to use is dependent on the display used, so it's better to add them when the display gets integrated. The pwm14 node could update still be added here, but that too might as well wait until there's something to use it. So I think this patch can just be dropped. -Alex > >> + }; >> }; >> >> &uart0 { >> @@ -35,3 +61,9 @@ &uart0 { >> pinctrl-0 = <&uart0_2_cfg>; >> status = "okay"; >> }; >> + >> +&pwm14 { >> + pinctrl-names = "default"; >> + pinctrl-0 = <&pwm14_1_cfg>; > .. >> + status = "disabled"; > ditto > >> +}; >> -- >> 2.43.0 >> >
Hi Alex, On 09:23 Fri 11 Apr , Alex Elder wrote: > On 4/11/25 9:05 AM, Yixun Lan wrote: > > > > On 21:14 Fri 11 Apr , Guodong Xu wrote: > >> Add a PWM-based backlight node for the Banana Pi BPI-F3 board, > >> using PWM14. The backlight is defined as a 'pwm-backlight' device with > >> brightness levels and a default brightness setting. PWM14 is assigned > >> a period length of 2000 nanoseconds. > >> > >> This configuration was used to verify PWM driver changes, with PWM14 > >> tested and its waveform confirmed as correct. > >> > >> The node status is set to "disabled", and should be enabled when the > >> display driver is ready. > >> > > .. see comments below > >> Signed-off-by: Guodong Xu <guodong@riscstar.com> > >> --- > >> .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ > >> 1 file changed, 32 insertions(+) > >> > >> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > >> index 816ef1bc358e..d04b57ddeb46 100644 > >> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > >> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > >> @@ -28,6 +28,32 @@ led1 { > >> default-state = "on"; > >> }; > >> }; > >> + > >> + pwm_bl: lcd_backlight { > >> + compatible = "pwm-backlight"; > >> + > >> + pwms = <&pwm14 2000>; > >> + brightness-levels = < > >> + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > >> + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > >> + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 > >> + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 > >> + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 > >> + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 > >> + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 > >> + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > >> + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 > >> + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 > >> + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 > >> + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 > >> + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 > >> + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 > >> + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 > >> + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 > >> + >; > >> + default-brightness-level = <100>; > >> + status = "disabled"; > > I'm confused, has DT in board file with disabled status doesn't make sense? > > it doesn't really useful for placeholder, even worse that functionality may not > > verified, so I'd suggest sending along with display driver while at it.. > > I think I suggested he include this. Guodong tested PWM using > a backlight on a display connected to a Banana Pi PBI-F3 board. > The above numbers come directly from the downstream code, which > uses this PWM consistently as a display back light. > > But you're right, the exact set of numbers to use is dependent > on the display used, so it's better to add them when the display > gets integrated. > Ok > The pwm14 node could update still be added here, but that too > might as well wait until there's something to use it. So I > think this patch can just be dropped. > thanks for the explanation
On Fri, Apr 11, 2025 at 09:14:21PM +0800, Guodong Xu wrote: > Add a PWM-based backlight node for the Banana Pi BPI-F3 board, > using PWM14. The backlight is defined as a 'pwm-backlight' device with > brightness levels and a default brightness setting. PWM14 is assigned > a period length of 2000 nanoseconds. > > This configuration was used to verify PWM driver changes, with PWM14 > tested and its waveform confirmed as correct. > > The node status is set to "disabled", and should be enabled when the > display driver is ready. > > Signed-off-by: Guodong Xu <guodong@riscstar.com> > --- > .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > index 816ef1bc358e..d04b57ddeb46 100644 > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > @@ -28,6 +28,32 @@ led1 { > default-state = "on"; > }; > }; > + > + pwm_bl: lcd_backlight { > + compatible = "pwm-backlight"; > + > + pwms = <&pwm14 2000>; > + brightness-levels = < > + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 > + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 > + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 > + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 > + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 > + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 > + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 > + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 > + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 > + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 > + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 > + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 > + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 > + >; Can we simplify this level matrix? I see it is continous in most cases. Regards, Inochi
On Fri, Apr 11, 2025 at 09:23:29AM -0500, Alex Elder wrote: > On 4/11/25 9:05 AM, Yixun Lan wrote: > > > > On 21:14 Fri 11 Apr , Guodong Xu wrote: > > > Add a PWM-based backlight node for the Banana Pi BPI-F3 board, > > > using PWM14. The backlight is defined as a 'pwm-backlight' device with > > > brightness levels and a default brightness setting. PWM14 is assigned > > > a period length of 2000 nanoseconds. > > > > > > This configuration was used to verify PWM driver changes, with PWM14 > > > tested and its waveform confirmed as correct. > > > > > > The node status is set to "disabled", and should be enabled when the > > > display driver is ready. > > > > > .. see comments below > > > Signed-off-by: Guodong Xu <guodong@riscstar.com> > > > --- > > > .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ > > > 1 file changed, 32 insertions(+) > > > > > > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > index 816ef1bc358e..d04b57ddeb46 100644 > > > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > @@ -28,6 +28,32 @@ led1 { > > > default-state = "on"; > > > }; > > > }; > > > + > > > + pwm_bl: lcd_backlight { > > > + compatible = "pwm-backlight"; > > > + > > > + pwms = <&pwm14 2000>; > > > + brightness-levels = < > > > + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > > > + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > > > + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 > > > + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 > > > + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 > > > + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 > > > + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 > > > + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > > > + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 > > > + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 > > > + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 > > > + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 > > > + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 > > > + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 > > > + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 > > > + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 > > > + >; > > > + default-brightness-level = <100>; > > > + status = "disabled"; > > I'm confused, has DT in board file with disabled status doesn't make sense? > > it doesn't really useful for placeholder, even worse that functionality may not > > verified, so I'd suggest sending along with display driver while at it.. > > I think I suggested he include this. Guodong tested PWM using > a backlight on a display connected to a Banana Pi PBI-F3 board. > The above numbers come directly from the downstream code, which > uses this PWM consistently as a display back light. > > But you're right, the exact set of numbers to use is dependent > on the display used, so it's better to add them when the display > gets integrated. > > The pwm14 node could update still be added here, but that too > might as well wait until there's something to use it. So I > think this patch can just be dropped. > If this patch will be applied as it is after applying the display driver. I recommend to preserve this patch, but move out of this series and resend it as RFC. If this is only for test purpose, it is better to move this into the cover letter and address it is for testing. In most case, patches with some unmeet dependency should follow maintainer's request, or has specific purposes. It also needed to be marked as RFC. Regards, Inochi
On Sat, Apr 12, 2025 at 7:28 AM Inochi Amaoto <inochiama@gmail.com> wrote: > > On Fri, Apr 11, 2025 at 09:23:29AM -0500, Alex Elder wrote: > > On 4/11/25 9:05 AM, Yixun Lan wrote: > > > > > > On 21:14 Fri 11 Apr , Guodong Xu wrote: > > > > Add a PWM-based backlight node for the Banana Pi BPI-F3 board, > > > > using PWM14. The backlight is defined as a 'pwm-backlight' device with > > > > brightness levels and a default brightness setting. PWM14 is assigned > > > > a period length of 2000 nanoseconds. > > > > > > > > This configuration was used to verify PWM driver changes, with PWM14 > > > > tested and its waveform confirmed as correct. > > > > > > > > The node status is set to "disabled", and should be enabled when the > > > > display driver is ready. > > > > > > > .. see comments below > > > > Signed-off-by: Guodong Xu <guodong@riscstar.com> > > > > --- > > > > .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ > > > > 1 file changed, 32 insertions(+) > > > > > > > > diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > > index 816ef1bc358e..d04b57ddeb46 100644 > > > > --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > > +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts > > > > @@ -28,6 +28,32 @@ led1 { > > > > default-state = "on"; > > > > }; > > > > }; > > > > + > > > > + pwm_bl: lcd_backlight { > > > > + compatible = "pwm-backlight"; > > > > + > > > > + pwms = <&pwm14 2000>; > > > > + brightness-levels = < > > > > + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > > > > + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 > > > > + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 > > > > + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 > > > > + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 > > > > + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 > > > > + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 > > > > + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 > > > > + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 > > > > + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 > > > > + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 > > > > + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 > > > > + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 > > > > + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 > > > > + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 > > > > + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 > > > > + >; > > > > + default-brightness-level = <100>; > > > > + status = "disabled"; > > > I'm confused, has DT in board file with disabled status doesn't make sense? > > > it doesn't really useful for placeholder, even worse that functionality may not > > > verified, so I'd suggest sending along with display driver while at it.. > > > > I think I suggested he include this. Guodong tested PWM using > > a backlight on a display connected to a Banana Pi PBI-F3 board. > > The above numbers come directly from the downstream code, which > > uses this PWM consistently as a display back light. > > > > But you're right, the exact set of numbers to use is dependent > > on the display used, so it's better to add them when the display > > gets integrated. > > > > The pwm14 node could update still be added here, but that too > > might as well wait until there's something to use it. So I > > think this patch can just be dropped. > > > I checked the existing boards based on SpacemiT K1 Soc, all of them are following the same pinmux design of using pwm14 (and pinctrl group 1, ie. pwm14_1_cfg) as the display backlight control. That's why the code relating to pwm14, in my opinion, could be useful to others. > If this patch will be applied as it is after applying the display > driver. I recommend to preserve this patch, but move out of this > series and resend it as RFC. If this is only for test purpose, it > is better to move this into the cover letter and address it is for > testing. > Yes, it's for test purpose. So, let me move the code snippet into the cover letter in my next version. -Guodong > In most case, patches with some unmeet dependency should follow > maintainer's request, or has specific purposes. It also needed to > be marked as RFC. > > Regards, > Inochi >
Hello, On Fri, Apr 11, 2025 at 09:14:21PM +0800, Guodong Xu wrote: > +&pwm14 { > + pinctrl-names = "default"; > + pinctrl-0 = <&pwm14_1_cfg>; > + status = "disabled"; > +}; I wonder if the pinctrl properties can better be added to the SoC's .dtsi file. (Only applies if this is a canonical choice, i.e. there is no other possible output configuration.) Best regards Uwe
Hi Uwe, On 07:58 Mon 14 Apr , Uwe Kleine-König wrote: > Hello, > > On Fri, Apr 11, 2025 at 09:14:21PM +0800, Guodong Xu wrote: > > +&pwm14 { > > + pinctrl-names = "default"; > > + pinctrl-0 = <&pwm14_1_cfg>; > > + status = "disabled"; > > +}; > > I wonder if the pinctrl properties can better be added to the SoC's > .dtsi file. (Only applies if this is a canonical choice, i.e. there is > no other possible output configuration.) > I'd agree it's a good idea and should follow, but unfortunately in the practical case, all pwm able to route to at least two different pins.. https://developer.spacemit.com/documentation?token=YiJZwXA2Ri4nJikV9E1cp6nqnMh see section: 4.5 Multi-Function I/O Pin Assignments
diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts index 816ef1bc358e..d04b57ddeb46 100644 --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts @@ -28,6 +28,32 @@ led1 { default-state = "on"; }; }; + + pwm_bl: lcd_backlight { + compatible = "pwm-backlight"; + + pwms = <&pwm14 2000>; + brightness-levels = < + 0 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 + 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 + 40 40 40 40 40 40 40 40 40 41 42 43 44 45 46 47 + 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 + 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 + 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 + 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 + 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 + 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 + 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 + 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 + 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 + 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 + 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 + 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 + 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 + >; + default-brightness-level = <100>; + status = "disabled"; + }; }; &uart0 { @@ -35,3 +61,9 @@ &uart0 { pinctrl-0 = <&uart0_2_cfg>; status = "okay"; }; + +&pwm14 { + pinctrl-names = "default"; + pinctrl-0 = <&pwm14_1_cfg>; + status = "disabled"; +};
Add a PWM-based backlight node for the Banana Pi BPI-F3 board, using PWM14. The backlight is defined as a 'pwm-backlight' device with brightness levels and a default brightness setting. PWM14 is assigned a period length of 2000 nanoseconds. This configuration was used to verify PWM driver changes, with PWM14 tested and its waveform confirmed as correct. The node status is set to "disabled", and should be enabled when the display driver is ready. Signed-off-by: Guodong Xu <guodong@riscstar.com> --- .../boot/dts/spacemit/k1-bananapi-f3.dts | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+)