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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
359 lines
8.4 KiB
C
359 lines
8.4 KiB
C
![]() |
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
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*/
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#include <linux/clk.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mailbox_controller.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/slab.h>
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/* Transmit Register */
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#define IMX_MU_xTRn(x) (0x00 + 4 * (x))
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/* Receive Register */
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#define IMX_MU_xRRn(x) (0x10 + 4 * (x))
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/* Status Register */
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#define IMX_MU_xSR 0x20
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#define IMX_MU_xSR_GIPn(x) BIT(28 + (3 - (x)))
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#define IMX_MU_xSR_RFn(x) BIT(24 + (3 - (x)))
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#define IMX_MU_xSR_TEn(x) BIT(20 + (3 - (x)))
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#define IMX_MU_xSR_BRDIP BIT(9)
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/* Control Register */
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#define IMX_MU_xCR 0x24
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/* General Purpose Interrupt Enable */
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#define IMX_MU_xCR_GIEn(x) BIT(28 + (3 - (x)))
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/* Receive Interrupt Enable */
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#define IMX_MU_xCR_RIEn(x) BIT(24 + (3 - (x)))
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/* Transmit Interrupt Enable */
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#define IMX_MU_xCR_TIEn(x) BIT(20 + (3 - (x)))
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/* General Purpose Interrupt Request */
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#define IMX_MU_xCR_GIRn(x) BIT(16 + (3 - (x)))
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#define IMX_MU_CHANS 16
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#define IMX_MU_CHAN_NAME_SIZE 20
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enum imx_mu_chan_type {
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IMX_MU_TYPE_TX, /* Tx */
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IMX_MU_TYPE_RX, /* Rx */
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IMX_MU_TYPE_TXDB, /* Tx doorbell */
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IMX_MU_TYPE_RXDB, /* Rx doorbell */
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};
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struct imx_mu_con_priv {
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unsigned int idx;
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char irq_desc[IMX_MU_CHAN_NAME_SIZE];
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enum imx_mu_chan_type type;
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struct mbox_chan *chan;
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struct tasklet_struct txdb_tasklet;
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};
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struct imx_mu_priv {
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struct device *dev;
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void __iomem *base;
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spinlock_t xcr_lock; /* control register lock */
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struct mbox_controller mbox;
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struct mbox_chan mbox_chans[IMX_MU_CHANS];
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struct imx_mu_con_priv con_priv[IMX_MU_CHANS];
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struct clk *clk;
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int irq;
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bool side_b;
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};
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static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
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{
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return container_of(mbox, struct imx_mu_priv, mbox);
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}
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static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
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{
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iowrite32(val, priv->base + offs);
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}
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static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
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{
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return ioread32(priv->base + offs);
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}
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static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, u32 set, u32 clr)
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{
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unsigned long flags;
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u32 val;
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spin_lock_irqsave(&priv->xcr_lock, flags);
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val = imx_mu_read(priv, IMX_MU_xCR);
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val &= ~clr;
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val |= set;
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imx_mu_write(priv, val, IMX_MU_xCR);
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spin_unlock_irqrestore(&priv->xcr_lock, flags);
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return val;
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}
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static void imx_mu_txdb_tasklet(unsigned long data)
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{
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struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;
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mbox_chan_txdone(cp->chan, 0);
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}
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static irqreturn_t imx_mu_isr(int irq, void *p)
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{
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struct mbox_chan *chan = p;
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struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
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struct imx_mu_con_priv *cp = chan->con_priv;
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u32 val, ctrl, dat;
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ctrl = imx_mu_read(priv, IMX_MU_xCR);
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val = imx_mu_read(priv, IMX_MU_xSR);
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switch (cp->type) {
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case IMX_MU_TYPE_TX:
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val &= IMX_MU_xSR_TEn(cp->idx) &
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(ctrl & IMX_MU_xCR_TIEn(cp->idx));
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break;
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case IMX_MU_TYPE_RX:
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val &= IMX_MU_xSR_RFn(cp->idx) &
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(ctrl & IMX_MU_xCR_RIEn(cp->idx));
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break;
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case IMX_MU_TYPE_RXDB:
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val &= IMX_MU_xSR_GIPn(cp->idx) &
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(ctrl & IMX_MU_xCR_GIEn(cp->idx));
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break;
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default:
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break;
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}
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if (!val)
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return IRQ_NONE;
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if (val == IMX_MU_xSR_TEn(cp->idx)) {
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imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
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mbox_chan_txdone(chan, 0);
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} else if (val == IMX_MU_xSR_RFn(cp->idx)) {
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dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx));
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mbox_chan_received_data(chan, (void *)&dat);
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} else if (val == IMX_MU_xSR_GIPn(cp->idx)) {
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imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), IMX_MU_xSR);
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mbox_chan_received_data(chan, NULL);
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} else {
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dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
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return IRQ_NONE;
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}
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return IRQ_HANDLED;
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}
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static int imx_mu_send_data(struct mbox_chan *chan, void *data)
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{
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struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
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struct imx_mu_con_priv *cp = chan->con_priv;
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u32 *arg = data;
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switch (cp->type) {
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case IMX_MU_TYPE_TX:
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imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx));
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imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0);
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break;
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case IMX_MU_TYPE_TXDB:
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imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIRn(cp->idx), 0);
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tasklet_schedule(&cp->txdb_tasklet);
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break;
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default:
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dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
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return -EINVAL;
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}
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return 0;
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}
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static int imx_mu_startup(struct mbox_chan *chan)
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{
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struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
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struct imx_mu_con_priv *cp = chan->con_priv;
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int ret;
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if (cp->type == IMX_MU_TYPE_TXDB) {
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/* Tx doorbell don't have ACK support */
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tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
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(unsigned long)cp);
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return 0;
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}
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ret = request_irq(priv->irq, imx_mu_isr, IRQF_SHARED, cp->irq_desc,
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chan);
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if (ret) {
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dev_err(priv->dev,
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"Unable to acquire IRQ %d\n", priv->irq);
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return ret;
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}
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switch (cp->type) {
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case IMX_MU_TYPE_RX:
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imx_mu_xcr_rmw(priv, IMX_MU_xCR_RIEn(cp->idx), 0);
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break;
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case IMX_MU_TYPE_RXDB:
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imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIEn(cp->idx), 0);
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break;
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default:
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break;
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}
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return 0;
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}
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static void imx_mu_shutdown(struct mbox_chan *chan)
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{
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struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
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struct imx_mu_con_priv *cp = chan->con_priv;
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if (cp->type == IMX_MU_TYPE_TXDB)
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tasklet_kill(&cp->txdb_tasklet);
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imx_mu_xcr_rmw(priv, 0,
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IMX_MU_xCR_TIEn(cp->idx) | IMX_MU_xCR_RIEn(cp->idx));
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free_irq(priv->irq, chan);
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}
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static const struct mbox_chan_ops imx_mu_ops = {
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.send_data = imx_mu_send_data,
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.startup = imx_mu_startup,
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.shutdown = imx_mu_shutdown,
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};
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static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
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const struct of_phandle_args *sp)
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{
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u32 type, idx, chan;
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if (sp->args_count != 2) {
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dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
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return ERR_PTR(-EINVAL);
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}
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type = sp->args[0]; /* channel type */
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idx = sp->args[1]; /* index */
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chan = type * 4 + idx;
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if (chan >= mbox->num_chans) {
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dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
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return ERR_PTR(-EINVAL);
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}
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return &mbox->chans[chan];
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}
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static void imx_mu_init_generic(struct imx_mu_priv *priv)
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{
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if (priv->side_b)
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return;
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/* Set default MU configuration */
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imx_mu_write(priv, 0, IMX_MU_xCR);
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}
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static int imx_mu_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct resource *iomem;
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struct imx_mu_priv *priv;
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unsigned int i;
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int ret;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->dev = dev;
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iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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priv->base = devm_ioremap_resource(&pdev->dev, iomem);
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if (IS_ERR(priv->base))
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return PTR_ERR(priv->base);
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priv->irq = platform_get_irq(pdev, 0);
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if (priv->irq < 0)
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return priv->irq;
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priv->clk = devm_clk_get(dev, NULL);
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if (IS_ERR(priv->clk)) {
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if (PTR_ERR(priv->clk) != -ENOENT)
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return PTR_ERR(priv->clk);
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priv->clk = NULL;
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}
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ret = clk_prepare_enable(priv->clk);
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if (ret) {
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dev_err(dev, "Failed to enable clock\n");
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return ret;
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}
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for (i = 0; i < IMX_MU_CHANS; i++) {
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struct imx_mu_con_priv *cp = &priv->con_priv[i];
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cp->idx = i % 4;
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cp->type = i >> 2;
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cp->chan = &priv->mbox_chans[i];
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priv->mbox_chans[i].con_priv = cp;
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snprintf(cp->irq_desc, sizeof(cp->irq_desc),
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"imx_mu_chan[%i-%i]", cp->type, cp->idx);
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}
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priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
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spin_lock_init(&priv->xcr_lock);
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priv->mbox.dev = dev;
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priv->mbox.ops = &imx_mu_ops;
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priv->mbox.chans = priv->mbox_chans;
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priv->mbox.num_chans = IMX_MU_CHANS;
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priv->mbox.of_xlate = imx_mu_xlate;
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priv->mbox.txdone_irq = true;
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platform_set_drvdata(pdev, priv);
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imx_mu_init_generic(priv);
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return mbox_controller_register(&priv->mbox);
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}
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static int imx_mu_remove(struct platform_device *pdev)
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{
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struct imx_mu_priv *priv = platform_get_drvdata(pdev);
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mbox_controller_unregister(&priv->mbox);
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clk_disable_unprepare(priv->clk);
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return 0;
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}
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static const struct of_device_id imx_mu_dt_ids[] = {
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{ .compatible = "fsl,imx6sx-mu" },
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{ },
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};
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MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
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static struct platform_driver imx_mu_driver = {
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.probe = imx_mu_probe,
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.remove = imx_mu_remove,
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.driver = {
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.name = "imx_mu",
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.of_match_table = imx_mu_dt_ids,
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},
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};
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module_platform_driver(imx_mu_driver);
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MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
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MODULE_DESCRIPTION("Message Unit driver for i.MX");
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MODULE_LICENSE("GPL v2");
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