![Eric Miao](/assets/img/avatar_default.png)
pxa-regs.h and hardware.h are not intended for use directly in driver code, remove those unnecessary references. Signed-off-by: Eric Miao <eric.miao@marvell.com>
549 lines
12 KiB
C
549 lines
12 KiB
C
/*
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* linux/arch/arm/mach-pxa/ssp.c
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*
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* based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
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*
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* Copyright (C) 2003 Russell King.
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* Copyright (C) 2003 Wolfson Microelectronics PLC
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* PXA2xx SSP driver. This provides the generic core for simple
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* IO-based SSP applications and allows easy port setup for DMA access.
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*
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* Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <asm/irq.h>
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#include <mach/hardware.h>
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#include <mach/ssp.h>
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#include <mach/regs-ssp.h>
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#define TIMEOUT 100000
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static irqreturn_t ssp_interrupt(int irq, void *dev_id)
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{
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struct ssp_dev *dev = dev_id;
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struct ssp_device *ssp = dev->ssp;
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unsigned int status;
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status = __raw_readl(ssp->mmio_base + SSSR);
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__raw_writel(status, ssp->mmio_base + SSSR);
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if (status & SSSR_ROR)
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printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port);
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if (status & SSSR_TUR)
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printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port);
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if (status & SSSR_BCE)
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printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port);
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return IRQ_HANDLED;
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}
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/**
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* ssp_write_word - write a word to the SSP port
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* @data: 32-bit, MSB justified data to write.
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*
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* Wait for a free entry in the SSP transmit FIFO, and write a data
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* word to the SSP port.
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*
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* The caller is expected to perform the necessary locking.
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*
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* Returns:
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* %-ETIMEDOUT timeout occurred
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* 0 success
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*/
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int ssp_write_word(struct ssp_dev *dev, u32 data)
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{
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struct ssp_device *ssp = dev->ssp;
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int timeout = TIMEOUT;
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while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_TNF)) {
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if (!--timeout)
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return -ETIMEDOUT;
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cpu_relax();
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}
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__raw_writel(data, ssp->mmio_base + SSDR);
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return 0;
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}
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/**
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* ssp_read_word - read a word from the SSP port
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*
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* Wait for a data word in the SSP receive FIFO, and return the
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* received data. Data is LSB justified.
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*
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* Note: Currently, if data is not expected to be received, this
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* function will wait for ever.
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*
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* The caller is expected to perform the necessary locking.
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*
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* Returns:
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* %-ETIMEDOUT timeout occurred
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* 32-bit data success
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*/
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int ssp_read_word(struct ssp_dev *dev, u32 *data)
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{
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struct ssp_device *ssp = dev->ssp;
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int timeout = TIMEOUT;
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while (!(__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE)) {
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if (!--timeout)
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return -ETIMEDOUT;
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cpu_relax();
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}
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*data = __raw_readl(ssp->mmio_base + SSDR);
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return 0;
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}
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/**
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* ssp_flush - flush the transmit and receive FIFOs
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*
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* Wait for the SSP to idle, and ensure that the receive FIFO
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* is empty.
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*
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* The caller is expected to perform the necessary locking.
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*/
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int ssp_flush(struct ssp_dev *dev)
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{
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struct ssp_device *ssp = dev->ssp;
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int timeout = TIMEOUT * 2;
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/* ensure TX FIFO is empty instead of not full */
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if (cpu_is_pxa3xx()) {
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while (__raw_readl(ssp->mmio_base + SSSR) & 0xf00) {
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if (!--timeout)
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return -ETIMEDOUT;
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cpu_relax();
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}
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timeout = TIMEOUT * 2;
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}
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do {
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while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_RNE) {
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if (!--timeout)
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return -ETIMEDOUT;
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(void)__raw_readl(ssp->mmio_base + SSDR);
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}
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if (!--timeout)
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return -ETIMEDOUT;
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} while (__raw_readl(ssp->mmio_base + SSSR) & SSSR_BSY);
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return 0;
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}
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/**
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* ssp_enable - enable the SSP port
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*
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* Turn on the SSP port.
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*/
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void ssp_enable(struct ssp_dev *dev)
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{
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struct ssp_device *ssp = dev->ssp;
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uint32_t sscr0;
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sscr0 = __raw_readl(ssp->mmio_base + SSCR0);
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sscr0 |= SSCR0_SSE;
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__raw_writel(sscr0, ssp->mmio_base + SSCR0);
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}
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/**
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* ssp_disable - shut down the SSP port
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*
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* Turn off the SSP port, optionally powering it down.
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*/
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void ssp_disable(struct ssp_dev *dev)
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{
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struct ssp_device *ssp = dev->ssp;
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uint32_t sscr0;
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sscr0 = __raw_readl(ssp->mmio_base + SSCR0);
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sscr0 &= ~SSCR0_SSE;
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__raw_writel(sscr0, ssp->mmio_base + SSCR0);
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}
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/**
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* ssp_save_state - save the SSP configuration
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* @ssp: pointer to structure to save SSP configuration
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*
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* Save the configured SSP state for suspend.
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*/
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void ssp_save_state(struct ssp_dev *dev, struct ssp_state *state)
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{
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struct ssp_device *ssp = dev->ssp;
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state->cr0 = __raw_readl(ssp->mmio_base + SSCR0);
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state->cr1 = __raw_readl(ssp->mmio_base + SSCR1);
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state->to = __raw_readl(ssp->mmio_base + SSTO);
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state->psp = __raw_readl(ssp->mmio_base + SSPSP);
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ssp_disable(dev);
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}
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/**
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* ssp_restore_state - restore a previously saved SSP configuration
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* @ssp: pointer to configuration saved by ssp_save_state
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*
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* Restore the SSP configuration saved previously by ssp_save_state.
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*/
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void ssp_restore_state(struct ssp_dev *dev, struct ssp_state *state)
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{
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struct ssp_device *ssp = dev->ssp;
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uint32_t sssr = SSSR_ROR | SSSR_TUR | SSSR_BCE;
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__raw_writel(sssr, ssp->mmio_base + SSSR);
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__raw_writel(state->cr0 & ~SSCR0_SSE, ssp->mmio_base + SSCR0);
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__raw_writel(state->cr1, ssp->mmio_base + SSCR1);
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__raw_writel(state->to, ssp->mmio_base + SSTO);
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__raw_writel(state->psp, ssp->mmio_base + SSPSP);
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__raw_writel(state->cr0, ssp->mmio_base + SSCR0);
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}
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/**
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* ssp_config - configure SSP port settings
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* @mode: port operating mode
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* @flags: port config flags
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* @psp_flags: port PSP config flags
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* @speed: port speed
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*
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* Port MUST be disabled by ssp_disable before making any config changes.
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*/
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int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed)
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{
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struct ssp_device *ssp = dev->ssp;
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dev->mode = mode;
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dev->flags = flags;
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dev->psp_flags = psp_flags;
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dev->speed = speed;
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/* set up port type, speed, port settings */
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__raw_writel((dev->speed | dev->mode), ssp->mmio_base + SSCR0);
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__raw_writel(dev->flags, ssp->mmio_base + SSCR1);
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__raw_writel(dev->psp_flags, ssp->mmio_base + SSPSP);
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return 0;
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}
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/**
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* ssp_init - setup the SSP port
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*
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* initialise and claim resources for the SSP port.
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*
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* Returns:
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* %-ENODEV if the SSP port is unavailable
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* %-EBUSY if the resources are already in use
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* %0 on success
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*/
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int ssp_init(struct ssp_dev *dev, u32 port, u32 init_flags)
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{
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struct ssp_device *ssp;
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int ret;
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ssp = ssp_request(port, "SSP");
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if (ssp == NULL)
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return -ENODEV;
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dev->ssp = ssp;
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dev->port = port;
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/* do we need to get irq */
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if (!(init_flags & SSP_NO_IRQ)) {
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ret = request_irq(ssp->irq, ssp_interrupt,
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0, "SSP", dev);
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if (ret)
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goto out_region;
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dev->irq = ssp->irq;
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} else
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dev->irq = NO_IRQ;
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/* turn on SSP port clock */
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clk_enable(ssp->clk);
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return 0;
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out_region:
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ssp_free(ssp);
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return ret;
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}
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/**
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* ssp_exit - undo the effects of ssp_init
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*
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* release and free resources for the SSP port.
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*/
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void ssp_exit(struct ssp_dev *dev)
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{
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struct ssp_device *ssp = dev->ssp;
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ssp_disable(dev);
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if (dev->irq != NO_IRQ)
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free_irq(dev->irq, dev);
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clk_disable(ssp->clk);
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ssp_free(ssp);
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}
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static DEFINE_MUTEX(ssp_lock);
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static LIST_HEAD(ssp_list);
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struct ssp_device *ssp_request(int port, const char *label)
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{
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struct ssp_device *ssp = NULL;
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mutex_lock(&ssp_lock);
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list_for_each_entry(ssp, &ssp_list, node) {
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if (ssp->port_id == port && ssp->use_count == 0) {
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ssp->use_count++;
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ssp->label = label;
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break;
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}
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}
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mutex_unlock(&ssp_lock);
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if (&ssp->node == &ssp_list)
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return NULL;
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return ssp;
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}
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EXPORT_SYMBOL(ssp_request);
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void ssp_free(struct ssp_device *ssp)
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{
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mutex_lock(&ssp_lock);
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if (ssp->use_count) {
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ssp->use_count--;
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ssp->label = NULL;
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} else
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dev_err(&ssp->pdev->dev, "device already free\n");
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mutex_unlock(&ssp_lock);
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}
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EXPORT_SYMBOL(ssp_free);
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static int __devinit ssp_probe(struct platform_device *pdev, int type)
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{
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struct resource *res;
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struct ssp_device *ssp;
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int ret = 0;
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ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL);
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if (ssp == NULL) {
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dev_err(&pdev->dev, "failed to allocate memory");
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return -ENOMEM;
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}
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ssp->pdev = pdev;
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ssp->clk = clk_get(&pdev->dev, NULL);
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if (IS_ERR(ssp->clk)) {
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ret = PTR_ERR(ssp->clk);
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goto err_free;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (res == NULL) {
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dev_err(&pdev->dev, "no memory resource defined\n");
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ret = -ENODEV;
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goto err_free_clk;
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}
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res = request_mem_region(res->start, res->end - res->start + 1,
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pdev->name);
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if (res == NULL) {
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dev_err(&pdev->dev, "failed to request memory resource\n");
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ret = -EBUSY;
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goto err_free_clk;
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}
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ssp->phys_base = res->start;
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ssp->mmio_base = ioremap(res->start, res->end - res->start + 1);
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if (ssp->mmio_base == NULL) {
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dev_err(&pdev->dev, "failed to ioremap() registers\n");
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ret = -ENODEV;
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goto err_free_mem;
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}
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ssp->irq = platform_get_irq(pdev, 0);
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if (ssp->irq < 0) {
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dev_err(&pdev->dev, "no IRQ resource defined\n");
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ret = -ENODEV;
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goto err_free_io;
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}
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res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
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if (res == NULL) {
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dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
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ret = -ENODEV;
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goto err_free_io;
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}
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ssp->drcmr_rx = res->start;
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res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
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if (res == NULL) {
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dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
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ret = -ENODEV;
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goto err_free_io;
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}
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ssp->drcmr_tx = res->start;
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/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
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* starts from 0, do a translation here
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*/
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ssp->port_id = pdev->id + 1;
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ssp->use_count = 0;
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ssp->type = type;
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mutex_lock(&ssp_lock);
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list_add(&ssp->node, &ssp_list);
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mutex_unlock(&ssp_lock);
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platform_set_drvdata(pdev, ssp);
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return 0;
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err_free_io:
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iounmap(ssp->mmio_base);
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err_free_mem:
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release_mem_region(res->start, res->end - res->start + 1);
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err_free_clk:
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clk_put(ssp->clk);
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err_free:
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kfree(ssp);
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return ret;
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}
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static int __devexit ssp_remove(struct platform_device *pdev)
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{
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struct resource *res;
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struct ssp_device *ssp;
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ssp = platform_get_drvdata(pdev);
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if (ssp == NULL)
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return -ENODEV;
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iounmap(ssp->mmio_base);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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release_mem_region(res->start, res->end - res->start + 1);
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clk_put(ssp->clk);
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mutex_lock(&ssp_lock);
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list_del(&ssp->node);
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mutex_unlock(&ssp_lock);
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kfree(ssp);
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return 0;
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}
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static int __devinit pxa25x_ssp_probe(struct platform_device *pdev)
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{
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return ssp_probe(pdev, PXA25x_SSP);
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}
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static int __devinit pxa25x_nssp_probe(struct platform_device *pdev)
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{
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return ssp_probe(pdev, PXA25x_NSSP);
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}
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static int __devinit pxa27x_ssp_probe(struct platform_device *pdev)
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{
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return ssp_probe(pdev, PXA27x_SSP);
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}
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static struct platform_driver pxa25x_ssp_driver = {
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.driver = {
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.name = "pxa25x-ssp",
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},
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.probe = pxa25x_ssp_probe,
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.remove = __devexit_p(ssp_remove),
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};
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static struct platform_driver pxa25x_nssp_driver = {
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.driver = {
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.name = "pxa25x-nssp",
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},
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.probe = pxa25x_nssp_probe,
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.remove = __devexit_p(ssp_remove),
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};
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static struct platform_driver pxa27x_ssp_driver = {
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.driver = {
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.name = "pxa27x-ssp",
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},
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.probe = pxa27x_ssp_probe,
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.remove = __devexit_p(ssp_remove),
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};
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static int __init pxa_ssp_init(void)
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{
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int ret = 0;
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ret = platform_driver_register(&pxa25x_ssp_driver);
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if (ret) {
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printk(KERN_ERR "failed to register pxa25x_ssp_driver");
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return ret;
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}
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ret = platform_driver_register(&pxa25x_nssp_driver);
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if (ret) {
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printk(KERN_ERR "failed to register pxa25x_nssp_driver");
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return ret;
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}
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ret = platform_driver_register(&pxa27x_ssp_driver);
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if (ret) {
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printk(KERN_ERR "failed to register pxa27x_ssp_driver");
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return ret;
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}
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return ret;
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}
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static void __exit pxa_ssp_exit(void)
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{
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platform_driver_unregister(&pxa25x_ssp_driver);
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platform_driver_unregister(&pxa25x_nssp_driver);
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platform_driver_unregister(&pxa27x_ssp_driver);
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}
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arch_initcall(pxa_ssp_init);
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module_exit(pxa_ssp_exit);
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EXPORT_SYMBOL(ssp_write_word);
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EXPORT_SYMBOL(ssp_read_word);
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EXPORT_SYMBOL(ssp_flush);
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EXPORT_SYMBOL(ssp_enable);
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EXPORT_SYMBOL(ssp_disable);
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EXPORT_SYMBOL(ssp_save_state);
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EXPORT_SYMBOL(ssp_restore_state);
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EXPORT_SYMBOL(ssp_init);
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EXPORT_SYMBOL(ssp_exit);
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EXPORT_SYMBOL(ssp_config);
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MODULE_DESCRIPTION("PXA SSP driver");
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MODULE_AUTHOR("Liam Girdwood");
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MODULE_LICENSE("GPL");
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