arm/mach-sa1100/ssp.c

1 // SPDX-License-Identifier: GPL-2.0-only
3  *  linux/arch/arm/mach-sa1100/ssp.c
8  *  IO-based SSP applications.
38  * ssp_write_word - write a word to the SSP port
39  * @data: 16-bit, MSB justified data to write.
41  * Wait for a free entry in the SSP transmit FIFO, and write a data
42  * word to the SSP port.  Wait for the SSP port to start sending
48  *   %-ETIMEDOUT	timeout occurred
56 	        if (!--timeout)  in ssp_write_word()
57 	        	return -ETIMEDOUT;  in ssp_write_word()
65 	        if (!--timeout)  in ssp_write_word()
66 	        	return -ETIMEDOUT;  in ssp_write_word()
74  * ssp_read_word - read a word from the SSP port
76  * Wait for a data word in the SSP receive FIFO, and return the
80  * function will wait for ever.
85  *   %-ETIMEDOUT	timeout occurred
86  *   16-bit data	success
93 	        if (!--timeout)  in ssp_read_word()
94 	        	return -ETIMEDOUT;  in ssp_read_word()
104  * ssp_flush - flush the transmit and receive FIFOs
106  * Wait for the SSP to idle, and ensure that the receive FIFO
112  *   %-ETIMEDOUT	timeout occurred
121 		        if (!--timeout)  in ssp_flush()
122 		        	return -ETIMEDOUT;  in ssp_flush()
125 	        if (!--timeout)  in ssp_flush()
126 	        	return -ETIMEDOUT;  in ssp_flush()
133  * ssp_enable - enable the SSP port
135  * Turn on the SSP port.
143  * ssp_disable - shut down the SSP port
153  * ssp_save_state - save the SSP configuration
160 	ssp->cr0 = Ser4SSCR0;  in ssp_save_state()
161 	ssp->cr1 = Ser4SSCR1;  in ssp_save_state()
167  * ssp_restore_state - restore a previously saved SSP configuration
176 	Ser4SSCR0 = ssp->cr0 & ~SSCR0_SSE;  in ssp_restore_state()
177 	Ser4SSCR1 = ssp->cr1;  in ssp_restore_state()
178 	Ser4SSCR0 = ssp->cr0;  in ssp_restore_state()
182  * ssp_init - setup the SSP port
187  *   %-ENODEV	if the SSP port is unavailable
188  *   %-EBUSY	if the resources are already in use
189  *   %0		on success
196 		return -ENODEV;  in ssp_init()
199 		return -EBUSY;  in ssp_init()
216  * ssp_exit - undo the effects of ssp_init