ASoC: OMAP4: Add support for McPDM

McPDM is the interface between Phoenix audio codec
and the OMAP4430 processor. It enables data to be transfered
to/from Phoenix at sample rates of 88.4 or 96 KHz.
Signed-off-by: NJorge Eduardo Candelaria <jorge.candelaria@ti.com>
Signed-off-by: NMargarita Olaya <x0080101@ti.com>
Acked-by: NLiam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/omap/mcpdm.c

+/*
+ * mcpdm.c  --  McPDM interface driver
+ *
+ * Author: Jorge Eduardo Candelaria <x0107209@ti.com>
+ * Copyright (C) 2009 - Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/wait.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+
+#include "mcpdm.h"
+
+static struct omap_mcpdm *mcpdm;
+
+static inline void omap_mcpdm_write(u16 reg, u32 val)
+{
+       __raw_writel(val, mcpdm->io_base + reg);
+}
+
+static inline int omap_mcpdm_read(u16 reg)
+{
+       return __raw_readl(mcpdm->io_base + reg);
+}
+
+static void omap_mcpdm_reg_dump(void)
+{
+       dev_dbg(mcpdm->dev, "***********************\n");
+       dev_dbg(mcpdm->dev, "IRQSTATUS_RAW:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_IRQSTATUS_RAW));
+       dev_dbg(mcpdm->dev, "IRQSTATUS:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_IRQSTATUS));
+       dev_dbg(mcpdm->dev, "IRQENABLE_SET:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_IRQENABLE_SET));
+       dev_dbg(mcpdm->dev, "IRQENABLE_CLR:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_IRQENABLE_CLR));
+       dev_dbg(mcpdm->dev, "IRQWAKE_EN: 0x%04x\n",
+                       omap_mcpdm_read(MCPDM_IRQWAKE_EN));
+       dev_dbg(mcpdm->dev, "DMAENABLE_SET: 0x%04x\n",
+                       omap_mcpdm_read(MCPDM_DMAENABLE_SET));
+       dev_dbg(mcpdm->dev, "DMAENABLE_CLR:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_DMAENABLE_CLR));
+       dev_dbg(mcpdm->dev, "DMAWAKEEN:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_DMAWAKEEN));
+       dev_dbg(mcpdm->dev, "CTRL:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_CTRL));
+       dev_dbg(mcpdm->dev, "DN_DATA:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_DN_DATA));
+       dev_dbg(mcpdm->dev, "UP_DATA: 0x%04x\n",
+                       omap_mcpdm_read(MCPDM_UP_DATA));
+       dev_dbg(mcpdm->dev, "FIFO_CTRL_DN: 0x%04x\n",
+                       omap_mcpdm_read(MCPDM_FIFO_CTRL_DN));
+       dev_dbg(mcpdm->dev, "FIFO_CTRL_UP:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_FIFO_CTRL_UP));
+       dev_dbg(mcpdm->dev, "DN_OFFSET:  0x%04x\n",
+                       omap_mcpdm_read(MCPDM_DN_OFFSET));
+       dev_dbg(mcpdm->dev, "***********************\n");
+}
+
+/*
+ * Takes the McPDM module in and out of reset state.
+ * Uplink and downlink can be reset individually.
+ */
+static void omap_mcpdm_reset_capture(int reset)
+{
+       int ctrl = omap_mcpdm_read(MCPDM_CTRL);
+
+       if (reset)
+               ctrl |= SW_UP_RST;
+       else
+               ctrl &= ~SW_UP_RST;
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+}
+
+static void omap_mcpdm_reset_playback(int reset)
+{
+       int ctrl = omap_mcpdm_read(MCPDM_CTRL);
+
+       if (reset)
+               ctrl |= SW_DN_RST;
+       else
+               ctrl &= ~SW_DN_RST;
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+}
+
+/*
+ * Enables the transfer through the PDM interface to/from the Phoenix
+ * codec by enabling the corresponding UP or DN channels.
+ */
+void omap_mcpdm_start(int stream)
+{
+       int ctrl = omap_mcpdm_read(MCPDM_CTRL);
+
+       if (stream)
+               ctrl |= mcpdm->up_channels;
+       else
+               ctrl |= mcpdm->dn_channels;
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+}
+
+/*
+ * Disables the transfer through the PDM interface to/from the Phoenix
+ * codec by disabling the corresponding UP or DN channels.
+ */
+void omap_mcpdm_stop(int stream)
+{
+       int ctrl = omap_mcpdm_read(MCPDM_CTRL);
+
+       if (stream)
+               ctrl &= ~mcpdm->up_channels;
+       else
+               ctrl &= ~mcpdm->dn_channels;
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+}
+
+/*
+ * Configures McPDM uplink for audio recording.
+ * This function should be called before omap_mcpdm_start.
+ */
+int omap_mcpdm_capture_open(struct omap_mcpdm_link *uplink)
+{
+       int irq_mask = 0;
+       int ctrl;
+
+       if (!uplink)
+               return -EINVAL;
+
+       mcpdm->uplink = uplink;
+
+       /* Enable irq request generation */
+       irq_mask |= uplink->irq_mask & MCPDM_UPLINK_IRQ_MASK;
+       omap_mcpdm_write(MCPDM_IRQENABLE_SET, irq_mask);
+
+       /* Configure uplink threshold */
+       if (uplink->threshold > UP_THRES_MAX)
+               uplink->threshold = UP_THRES_MAX;
+
+       omap_mcpdm_write(MCPDM_FIFO_CTRL_UP, uplink->threshold);
+
+       /* Configure DMA controller */
+       omap_mcpdm_write(MCPDM_DMAENABLE_SET, DMA_UP_ENABLE);
+
+       /* Set pdm out format */
+       ctrl = omap_mcpdm_read(MCPDM_CTRL);
+       ctrl &= ~PDMOUTFORMAT;
+       ctrl |= uplink->format & PDMOUTFORMAT;
+
+       /* Uplink channels */
+       mcpdm->up_channels = uplink->channels & (PDM_UP_MASK | PDM_STATUS_MASK);
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+
+       return 0;
+}
+
+/*
+ * Configures McPDM downlink for audio playback.
+ * This function should be called before omap_mcpdm_start.
+ */
+int omap_mcpdm_playback_open(struct omap_mcpdm_link *downlink)
+{
+       int irq_mask = 0;
+       int ctrl;
+
+       if (!downlink)
+               return -EINVAL;
+
+       mcpdm->downlink = downlink;
+
+       /* Enable irq request generation */
+       irq_mask |= downlink->irq_mask & MCPDM_DOWNLINK_IRQ_MASK;
+       omap_mcpdm_write(MCPDM_IRQENABLE_SET, irq_mask);
+
+       /* Configure uplink threshold */
+       if (downlink->threshold > DN_THRES_MAX)
+               downlink->threshold = DN_THRES_MAX;
+
+       omap_mcpdm_write(MCPDM_FIFO_CTRL_DN, downlink->threshold);
+
+       /* Enable DMA request generation */
+       omap_mcpdm_write(MCPDM_DMAENABLE_SET, DMA_DN_ENABLE);
+
+       /* Set pdm out format */
+       ctrl = omap_mcpdm_read(MCPDM_CTRL);
+       ctrl &= ~PDMOUTFORMAT;
+       ctrl |= downlink->format & PDMOUTFORMAT;
+
+       /* Downlink channels */
+       mcpdm->dn_channels = downlink->channels & (PDM_DN_MASK | PDM_CMD_MASK);
+
+       omap_mcpdm_write(MCPDM_CTRL, ctrl);
+
+       return 0;
+}
+
+/*
+ * Cleans McPDM uplink configuration.
+ * This function should be called when the stream is closed.
+ */
+int omap_mcpdm_capture_close(struct omap_mcpdm_link *uplink)
+{
+       int irq_mask = 0;
+
+       if (!uplink)
+               return -EINVAL;
+
+       /* Disable irq request generation */
+       irq_mask |= uplink->irq_mask & MCPDM_UPLINK_IRQ_MASK;
+       omap_mcpdm_write(MCPDM_IRQENABLE_CLR, irq_mask);
+
+       /* Disable DMA request generation */
+       omap_mcpdm_write(MCPDM_DMAENABLE_CLR, DMA_UP_ENABLE);
+
+       /* Clear Downlink channels */
+       mcpdm->up_channels = 0;
+
+       mcpdm->uplink = NULL;
+
+       return 0;
+}
+
+/*
+ * Cleans McPDM downlink configuration.
+ * This function should be called when the stream is closed.
+ */
+int omap_mcpdm_playback_close(struct omap_mcpdm_link *downlink)
+{
+       int irq_mask = 0;
+
+       if (!downlink)
+               return -EINVAL;
+
+       /* Disable irq request generation */
+       irq_mask |= downlink->irq_mask & MCPDM_DOWNLINK_IRQ_MASK;
+       omap_mcpdm_write(MCPDM_IRQENABLE_CLR, irq_mask);
+
+       /* Disable DMA request generation */
+       omap_mcpdm_write(MCPDM_DMAENABLE_CLR, DMA_DN_ENABLE);
+
+       /* clear Downlink channels */
+       mcpdm->dn_channels = 0;
+
+       mcpdm->downlink = NULL;
+
+       return 0;
+}
+
+static irqreturn_t omap_mcpdm_irq_handler(int irq, void *dev_id)
+{
+       struct omap_mcpdm *mcpdm_irq = dev_id;
+       int irq_status;
+
+       irq_status = omap_mcpdm_read(MCPDM_IRQSTATUS);
+
+       /* Acknowledge irq event */
+       omap_mcpdm_write(MCPDM_IRQSTATUS, irq_status);
+
+       if (irq & MCPDM_DN_IRQ_FULL) {
+               dev_err(mcpdm_irq->dev, "DN FIFO error %x\n", irq_status);
+               omap_mcpdm_reset_playback(1);
+               omap_mcpdm_playback_open(mcpdm_irq->downlink);
+               omap_mcpdm_reset_playback(0);
+       }
+
+       if (irq & MCPDM_DN_IRQ_EMPTY) {
+               dev_err(mcpdm_irq->dev, "DN FIFO error %x\n", irq_status);
+               omap_mcpdm_reset_playback(1);
+               omap_mcpdm_playback_open(mcpdm_irq->downlink);
+               omap_mcpdm_reset_playback(0);
+       }
+
+       if (irq & MCPDM_DN_IRQ) {
+               dev_dbg(mcpdm_irq->dev, "DN write request\n");
+       }
+
+       if (irq & MCPDM_UP_IRQ_FULL) {
+               dev_err(mcpdm_irq->dev, "UP FIFO error %x\n", irq_status);
+               omap_mcpdm_reset_capture(1);
+               omap_mcpdm_capture_open(mcpdm_irq->uplink);
+               omap_mcpdm_reset_capture(0);
+       }
+
+       if (irq & MCPDM_UP_IRQ_EMPTY) {
+               dev_err(mcpdm_irq->dev, "UP FIFO error %x\n", irq_status);
+               omap_mcpdm_reset_capture(1);
+               omap_mcpdm_capture_open(mcpdm_irq->uplink);
+               omap_mcpdm_reset_capture(0);
+       }
+
+       if (irq & MCPDM_UP_IRQ) {
+               dev_dbg(mcpdm_irq->dev, "UP write request\n");
+       }
+
+       return IRQ_HANDLED;
+}
+
+int omap_mcpdm_request(void)
+{
+       int ret;
+
+       clk_enable(mcpdm->clk);
+
+       spin_lock(&mcpdm->lock);
+
+       if (!mcpdm->free) {
+               dev_err(mcpdm->dev, "McPDM interface is in use\n");
+               spin_unlock(&mcpdm->lock);
+               ret = -EBUSY;
+               goto err;
+       }
+       mcpdm->free = 0;
+
+       spin_unlock(&mcpdm->lock);
+
+       /* Disable lines while request is ongoing */
+       omap_mcpdm_write(MCPDM_CTRL, 0x00);
+
+       ret = request_irq(mcpdm->irq, omap_mcpdm_irq_handler,
+                               0, "McPDM", (void *)mcpdm);
+       if (ret) {
+               dev_err(mcpdm->dev, "Request for McPDM IRQ failed\n");
+               goto err;
+       }
+
+       return 0;
+
+err:
+       clk_disable(mcpdm->clk);
+       return ret;
+}
+
+void omap_mcpdm_free(void)
+{
+       spin_lock(&mcpdm->lock);
+       if (mcpdm->free) {
+               dev_err(mcpdm->dev, "McPDM interface is already free\n");
+               spin_unlock(&mcpdm->lock);
+               return;
+       }
+       mcpdm->free = 1;
+       spin_unlock(&mcpdm->lock);
+
+       clk_disable(mcpdm->clk);
+
+       free_irq(mcpdm->irq, (void *)mcpdm);
+}
+
+/* Enable/disable DC offset cancelation for the analog
+ * headset path (PDM channels 1 and 2).
+ */
+int omap_mcpdm_set_offset(int offset1, int offset2)
+{
+       int offset;
+
+       if ((offset1 > DN_OFST_MAX) || (offset2 > DN_OFST_MAX))
+               return -EINVAL;
+
+       offset = (offset1 << DN_OFST_RX1) | (offset2 << DN_OFST_RX2);
+
+       /* offset cancellation for channel 1 */
+       if (offset1)
+               offset |= DN_OFST_RX1_EN;
+       else
+               offset &= ~DN_OFST_RX1_EN;
+
+       /* offset cancellation for channel 2 */
+       if (offset2)
+               offset |= DN_OFST_RX2_EN;
+       else
+               offset &= ~DN_OFST_RX2_EN;
+
+       omap_mcpdm_write(MCPDM_DN_OFFSET, offset);
+
+       return 0;
+}
+
+static int __devinit omap_mcpdm_probe(struct platform_device *pdev)
+{
+       struct resource *res;
+       int ret = 0;
+
+       mcpdm = kzalloc(sizeof(struct omap_mcpdm), GFP_KERNEL);
+       if (!mcpdm) {
+               ret = -ENOMEM;
+               goto exit;
+       }
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (res == NULL) {
+               dev_err(&pdev->dev, "no resource\n");
+               goto err_resource;
+       }
+
+       spin_lock_init(&mcpdm->lock);
+       mcpdm->free = 1;
+       mcpdm->io_base = ioremap(res->start, resource_size(res));
+       if (!mcpdm->io_base) {
+               ret = -ENOMEM;
+               goto err_resource;
+       }
+
+       mcpdm->irq = platform_get_irq(pdev, 0);
+
+       mcpdm->clk = clk_get(&pdev->dev, "pdm_ck");
+       if (IS_ERR(mcpdm->clk)) {
+               ret = PTR_ERR(mcpdm->clk);
+               dev_err(&pdev->dev, "unable to get pdm_ck: %d\n", ret);
+               goto err_clk;
+       }
+
+       mcpdm->dev = &pdev->dev;
+       platform_set_drvdata(pdev, mcpdm);
+
+       return 0;
+
+err_clk:
+       iounmap(mcpdm->io_base);
+err_resource:
+       kfree(mcpdm);
+exit:
+       return ret;
+}
+
+static int __devexit omap_mcpdm_remove(struct platform_device *pdev)
+{
+       struct omap_mcpdm *mcpdm_ptr = platform_get_drvdata(pdev);
+
+       platform_set_drvdata(pdev, NULL);
+
+       clk_put(mcpdm_ptr->clk);
+
+       iounmap(mcpdm_ptr->io_base);
+
+       mcpdm_ptr->clk = NULL;
+       mcpdm_ptr->free = 0;
+       mcpdm_ptr->dev = NULL;
+
+       kfree(mcpdm_ptr);
+
+       return 0;
+}
+
+static struct platform_driver omap_mcpdm_driver = {
+       .probe = omap_mcpdm_probe,
+       .remove = __devexit_p(omap_mcpdm_remove),
+       .driver = {
+               .name = "omap-mcpdm",
+       },
+};
+
+static struct platform_device *omap_mcpdm_device;
+
+static int __init omap_mcpdm_init(void)
+{
+       return platform_driver_register(&omap_mcpdm_driver);
+}
+arch_initcall(omap_mcpdm_init);

sound/soc/omap/mcpdm.h

+/*
+ * mcpdm.h -- Defines for McPDM driver
+ *
+ * Author: Jorge Eduardo Candelaria <x0107209@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+/* McPDM registers */
+
+#define MCPDM_REVISION         0x00
+#define MCPDM_SYSCONFIG                0x10
+#define MCPDM_IRQSTATUS_RAW    0x24
+#define MCPDM_IRQSTATUS                0x28
+#define MCPDM_IRQENABLE_SET    0x2C
+#define MCPDM_IRQENABLE_CLR    0x30
+#define MCPDM_IRQWAKE_EN       0x34
+#define MCPDM_DMAENABLE_SET    0x38
+#define MCPDM_DMAENABLE_CLR    0x3C
+#define MCPDM_DMAWAKEEN                0x40
+#define MCPDM_CTRL             0x44
+#define MCPDM_DN_DATA          0x48
+#define MCPDM_UP_DATA          0x4C
+#define MCPDM_FIFO_CTRL_DN     0x50
+#define MCPDM_FIFO_CTRL_UP     0x54
+#define MCPDM_DN_OFFSET                0x58
+
+/*
+ * MCPDM_IRQ bit fields
+ * IRQSTATUS_RAW, IRQSTATUS, IRQENABLE_SET, IRQENABLE_CLR
+ */
+
+#define MCPDM_DN_IRQ                   (1 << 0)
+#define MCPDM_DN_IRQ_EMPTY             (1 << 1)
+#define MCPDM_DN_IRQ_ALMST_EMPTY       (1 << 2)
+#define MCPDM_DN_IRQ_FULL              (1 << 3)
+
+#define MCPDM_UP_IRQ                   (1 << 8)
+#define MCPDM_UP_IRQ_EMPTY             (1 << 9)
+#define MCPDM_UP_IRQ_ALMST_FULL                (1 << 10)
+#define MCPDM_UP_IRQ_FULL              (1 << 11)
+
+#define MCPDM_DOWNLINK_IRQ_MASK                0x00F
+#define MCPDM_UPLINK_IRQ_MASK          0xF00
+
+/*
+ * MCPDM_DMAENABLE bit fields
+ */
+
+#define DMA_DN_ENABLE          0x1
+#define DMA_UP_ENABLE          0x2
+
+/*
+ * MCPDM_CTRL bit fields
+ */
+
+#define PDM_UP1_EN             0x0001
+#define PDM_UP2_EN             0x0002
+#define PDM_UP3_EN             0x0004
+#define PDM_DN1_EN             0x0008
+#define PDM_DN2_EN             0x0010
+#define PDM_DN3_EN             0x0020
+#define PDM_DN4_EN             0x0040
+#define PDM_DN5_EN             0x0080
+#define PDMOUTFORMAT           0x0100
+#define CMD_INT                        0x0200
+#define STATUS_INT             0x0400
+#define SW_UP_RST              0x0800
+#define SW_DN_RST              0x1000
+#define PDM_UP_MASK            0x007
+#define PDM_DN_MASK            0x0F8
+#define PDM_CMD_MASK           0x200
+#define PDM_STATUS_MASK                0x400
+
+
+#define PDMOUTFORMAT_LJUST     (0 << 8)
+#define PDMOUTFORMAT_RJUST     (1 << 8)
+
+/*
+ * MCPDM_FIFO_CTRL bit fields
+ */
+
+#define UP_THRES_MAX           0xF
+#define DN_THRES_MAX           0xF
+
+/*
+ * MCPDM_DN_OFFSET bit fields
+ */
+
+#define DN_OFST_RX1_EN         0x0001
+#define DN_OFST_RX2_EN         0x0100
+
+#define DN_OFST_RX1            1
+#define DN_OFST_RX2            9
+#define DN_OFST_MAX            0x1F
+
+#define MCPDM_UPLINK           1
+#define MCPDM_DOWNLINK         2
+
+struct omap_mcpdm_link {
+       int irq_mask;
+       int threshold;
+       int format;
+       int channels;
+};
+
+struct omap_mcpdm_platform_data {
+       unsigned long phys_base;
+       u16 irq;
+};
+
+struct omap_mcpdm {
+       struct device *dev;
+       unsigned long phys_base;
+       void __iomem *io_base;
+       u8 free;
+       int irq;
+
+       spinlock_t lock;
+       struct omap_mcpdm_platform_data *pdata;
+       struct clk *clk;
+       struct omap_mcpdm_link *downlink;
+       struct omap_mcpdm_link *uplink;
+       struct completion irq_completion;
+
+       int dn_channels;
+       int up_channels;
+};
+
+extern void omap_mcpdm_start(int stream);
+extern void omap_mcpdm_stop(int stream);
+extern int omap_mcpdm_capture_open(struct omap_mcpdm_link *uplink);
+extern int omap_mcpdm_playback_open(struct omap_mcpdm_link *downlink);
+extern int omap_mcpdm_capture_close(struct omap_mcpdm_link *uplink);
+extern int omap_mcpdm_playback_close(struct omap_mcpdm_link *downlink);
+extern int omap_mcpdm_request(void);
+extern void omap_mcpdm_free(void);
+extern int omap_mcpdm_set_offset(int offset1, int offset2);