diff options
author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2023-04-13 09:16:42 +0300 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-05-15 16:25:56 +0300 |
commit | 7d3ee229ea51a17afc1e53272e2a8f377cc82ba2 (patch) | |
tree | 95995d1e6abaadf03ab5b3b338159db72139e2d9 /arch/powerpc/platforms/52xx | |
parent | da5311a4b852eaf2c0feac8b28884a8d8a801dfc (diff) | |
download | linux-7d3ee229ea51a17afc1e53272e2a8f377cc82ba2.tar.xz |
powerpc: Drop MPC5200 LocalPlus bus FIFO driver
While mpc5200b.dtsi contains a device that this driver can bind to, the
only purpose of a bound device is to be used by the four exported functions
mpc52xx_lpbfifo_submit(), mpc52xx_lpbfifo_abort(), mpc52xx_lpbfifo_poll()
and mpc52xx_lpbfifo_start_xfer(). However there are no callers to this
function and so the driver is effectively superfluous and can be deleted.
Also drop some defines and a struct from <asm/mpc52xx.h> that are unused
now together with the declarations of the four mentioned functions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230413061642.kqkor4wkt7lp2mhp@pengutronix.de
Diffstat (limited to 'arch/powerpc/platforms/52xx')
-rw-r--r-- | arch/powerpc/platforms/52xx/Kconfig | 5 | ||||
-rw-r--r-- | arch/powerpc/platforms/52xx/Makefile | 2 | ||||
-rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c | 594 |
3 files changed, 0 insertions, 601 deletions
diff --git a/arch/powerpc/platforms/52xx/Kconfig b/arch/powerpc/platforms/52xx/Kconfig index b72ed2950ca8..384e4bef2c28 100644 --- a/arch/powerpc/platforms/52xx/Kconfig +++ b/arch/powerpc/platforms/52xx/Kconfig @@ -54,8 +54,3 @@ config PPC_MPC5200_BUGFIX for MPC5200B based boards. It is safe to say 'Y' here - -config PPC_MPC5200_LPBFIFO - tristate "MPC5200 LocalPlus bus FIFO driver" - depends on PPC_MPC52xx && PPC_BESTCOMM - select PPC_BESTCOMM_GEN_BD diff --git a/arch/powerpc/platforms/52xx/Makefile b/arch/powerpc/platforms/52xx/Makefile index f40d48eab779..1b1f72d83342 100644 --- a/arch/powerpc/platforms/52xx/Makefile +++ b/arch/powerpc/platforms/52xx/Makefile @@ -14,5 +14,3 @@ obj-$(CONFIG_PM) += mpc52xx_sleep.o mpc52xx_pm.o ifdef CONFIG_PPC_LITE5200 obj-$(CONFIG_PM) += lite5200_sleep.o lite5200_pm.o endif - -obj-$(CONFIG_PPC_MPC5200_LPBFIFO) += mpc52xx_lpbfifo.o diff --git a/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c b/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c deleted file mode 100644 index 6d1dd6e87478..000000000000 --- a/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c +++ /dev/null @@ -1,594 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * LocalPlus Bus FIFO driver for the Freescale MPC52xx. - * - * Copyright (C) 2009 Secret Lab Technologies Ltd. - * - * Todo: - * - Add support for multiple requests to be queued. - */ - -#include <linux/interrupt.h> -#include <linux/kernel.h> -#include <linux/of.h> -#include <linux/of_address.h> -#include <linux/of_irq.h> -#include <linux/of_platform.h> -#include <linux/spinlock.h> -#include <linux/module.h> -#include <asm/io.h> -#include <asm/mpc52xx.h> -#include <asm/time.h> - -#include <linux/fsl/bestcomm/bestcomm.h> -#include <linux/fsl/bestcomm/bestcomm_priv.h> -#include <linux/fsl/bestcomm/gen_bd.h> - -MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>"); -MODULE_DESCRIPTION("MPC5200 LocalPlus FIFO device driver"); -MODULE_LICENSE("GPL"); - -#define LPBFIFO_REG_PACKET_SIZE (0x00) -#define LPBFIFO_REG_START_ADDRESS (0x04) -#define LPBFIFO_REG_CONTROL (0x08) -#define LPBFIFO_REG_ENABLE (0x0C) -#define LPBFIFO_REG_BYTES_DONE_STATUS (0x14) -#define LPBFIFO_REG_FIFO_DATA (0x40) -#define LPBFIFO_REG_FIFO_STATUS (0x44) -#define LPBFIFO_REG_FIFO_CONTROL (0x48) -#define LPBFIFO_REG_FIFO_ALARM (0x4C) - -struct mpc52xx_lpbfifo { - struct device *dev; - phys_addr_t regs_phys; - void __iomem *regs; - int irq; - spinlock_t lock; - - struct bcom_task *bcom_tx_task; - struct bcom_task *bcom_rx_task; - struct bcom_task *bcom_cur_task; - - /* Current state data */ - struct mpc52xx_lpbfifo_request *req; - int dma_irqs_enabled; -}; - -/* The MPC5200 has only one fifo, so only need one instance structure */ -static struct mpc52xx_lpbfifo lpbfifo; - -/** - * mpc52xx_lpbfifo_kick - Trigger the next block of data to be transferred - * - * @req: Pointer to request structure - */ -static void mpc52xx_lpbfifo_kick(struct mpc52xx_lpbfifo_request *req) -{ - size_t transfer_size = req->size - req->pos; - struct bcom_bd *bd; - void __iomem *reg; - u32 *data; - int i; - int bit_fields; - int dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA); - int write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE; - int poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA; - - /* Set and clear the reset bits; is good practice in User Manual */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000); - - /* set master enable bit */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x00000001); - if (!dma) { - /* While the FIFO can be setup for transfer sizes as large as - * 16M-1, the FIFO itself is only 512 bytes deep and it does - * not generate interrupts for FIFO full events (only transfer - * complete will raise an IRQ). Therefore when not using - * Bestcomm to drive the FIFO it needs to either be polled, or - * transfers need to constrained to the size of the fifo. - * - * This driver restricts the size of the transfer - */ - if (transfer_size > 512) - transfer_size = 512; - - /* Load the FIFO with data */ - if (write) { - reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA; - data = req->data + req->pos; - for (i = 0; i < transfer_size; i += 4) - out_be32(reg, *data++); - } - - /* Unmask both error and completion irqs */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x00000301); - } else { - /* Choose the correct direction - * - * Configure the watermarks so DMA will always complete correctly. - * It may be worth experimenting with the ALARM value to see if - * there is a performance impact. However, if it is wrong there - * is a risk of DMA not transferring the last chunk of data - */ - if (write) { - out_be32(lpbfifo.regs + LPBFIFO_REG_FIFO_ALARM, 0x1e4); - out_8(lpbfifo.regs + LPBFIFO_REG_FIFO_CONTROL, 7); - lpbfifo.bcom_cur_task = lpbfifo.bcom_tx_task; - } else { - out_be32(lpbfifo.regs + LPBFIFO_REG_FIFO_ALARM, 0x1ff); - out_8(lpbfifo.regs + LPBFIFO_REG_FIFO_CONTROL, 0); - lpbfifo.bcom_cur_task = lpbfifo.bcom_rx_task; - - if (poll_dma) { - if (lpbfifo.dma_irqs_enabled) { - disable_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task)); - lpbfifo.dma_irqs_enabled = 0; - } - } else { - if (!lpbfifo.dma_irqs_enabled) { - enable_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task)); - lpbfifo.dma_irqs_enabled = 1; - } - } - } - - bd = bcom_prepare_next_buffer(lpbfifo.bcom_cur_task); - bd->status = transfer_size; - if (!write) { - /* - * In the DMA read case, the DMA doesn't complete, - * possibly due to incorrect watermarks in the ALARM - * and CONTROL regs. For now instead of trying to - * determine the right watermarks that will make this - * work, just increase the number of bytes the FIFO is - * expecting. - * - * When submitting another operation, the FIFO will get - * reset, so the condition of the FIFO waiting for a - * non-existent 4 bytes will get cleared. - */ - transfer_size += 4; /* BLECH! */ - } - bd->data[0] = req->data_phys + req->pos; - bcom_submit_next_buffer(lpbfifo.bcom_cur_task, NULL); - - /* error irq & master enabled bit */ - bit_fields = 0x00000201; - - /* Unmask irqs */ - if (write && (!poll_dma)) - bit_fields |= 0x00000100; /* completion irq too */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, bit_fields); - } - - /* Set transfer size, width, chip select and READ mode */ - out_be32(lpbfifo.regs + LPBFIFO_REG_START_ADDRESS, - req->offset + req->pos); - out_be32(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, transfer_size); - - bit_fields = req->cs << 24 | 0x000008; - if (!write) - bit_fields |= 0x010000; /* read mode */ - out_be32(lpbfifo.regs + LPBFIFO_REG_CONTROL, bit_fields); - - /* Kick it off */ - if (!lpbfifo.req->defer_xfer_start) - out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01); - if (dma) - bcom_enable(lpbfifo.bcom_cur_task); -} - -/** - * mpc52xx_lpbfifo_irq - IRQ handler for LPB FIFO - * @irq: IRQ number to be handled - * @dev_id: device ID cookie - * - * On transmit, the dma completion irq triggers before the fifo completion - * triggers. Handle the dma completion here instead of the LPB FIFO Bestcomm - * task completion irq because everything is not really done until the LPB FIFO - * completion irq triggers. - * - * In other words: - * For DMA, on receive, the "Fat Lady" is the bestcom completion irq. on - * transmit, the fifo completion irq is the "Fat Lady". The opera (or in this - * case the DMA/FIFO operation) is not finished until the "Fat Lady" sings. - * - * Reasons for entering this routine: - * 1) PIO mode rx and tx completion irq - * 2) DMA interrupt mode tx completion irq - * 3) DMA polled mode tx - * - * Exit conditions: - * 1) Transfer aborted - * 2) FIFO complete without DMA; more data to do - * 3) FIFO complete without DMA; all data transferred - * 4) FIFO complete using DMA - * - * Condition 1 can occur regardless of whether or not DMA is used. - * It requires executing the callback to report the error and exiting - * immediately. - * - * Condition 2 requires programming the FIFO with the next block of data - * - * Condition 3 requires executing the callback to report completion - * - * Condition 4 means the same as 3, except that we also retrieve the bcom - * buffer so DMA doesn't get clogged up. - * - * To make things trickier, the spinlock must be dropped before - * executing the callback, otherwise we could end up with a deadlock - * or nested spinlock condition. The out path is non-trivial, so - * extra fiddling is done to make sure all paths lead to the same - * outbound code. - * - * Return: irqreturn code (%IRQ_HANDLED) - */ -static irqreturn_t mpc52xx_lpbfifo_irq(int irq, void *dev_id) -{ - struct mpc52xx_lpbfifo_request *req; - u32 status = in_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS); - void __iomem *reg; - u32 *data; - int count, i; - int do_callback = 0; - u32 ts; - unsigned long flags; - int dma, write, poll_dma; - - spin_lock_irqsave(&lpbfifo.lock, flags); - ts = mftb(); - - req = lpbfifo.req; - if (!req) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - pr_err("bogus LPBFIFO IRQ\n"); - return IRQ_HANDLED; - } - - dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA); - write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE; - poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA; - - if (dma && !write) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - pr_err("bogus LPBFIFO IRQ (dma and not writing)\n"); - return IRQ_HANDLED; - } - - if ((status & 0x01) == 0) { - goto out; - } - - /* check abort bit */ - if (status & 0x10) { - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000); - do_callback = 1; - goto out; - } - - /* Read result from hardware */ - count = in_be32(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS); - count &= 0x00ffffff; - - if (!dma && !write) { - /* copy the data out of the FIFO */ - reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA; - data = req->data + req->pos; - for (i = 0; i < count; i += 4) - *data++ = in_be32(reg); - } - - /* Update transfer position and count */ - req->pos += count; - - /* Decide what to do next */ - if (req->size - req->pos) - mpc52xx_lpbfifo_kick(req); /* more work to do */ - else - do_callback = 1; - - out: - /* Clear the IRQ */ - out_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS, 0x01); - - if (dma && (status & 0x11)) { - /* - * Count the DMA as complete only when the FIFO completion - * status or abort bits are set. - * - * (status & 0x01) should always be the case except sometimes - * when using polled DMA. - * - * (status & 0x10) {transfer aborted}: This case needs more - * testing. - */ - bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL); - } - req->last_byte = ((u8 *)req->data)[req->size - 1]; - - /* When the do_callback flag is set; it means the transfer is finished - * so set the FIFO as idle */ - if (do_callback) - lpbfifo.req = NULL; - - if (irq != 0) /* don't increment on polled case */ - req->irq_count++; - - req->irq_ticks += mftb() - ts; - spin_unlock_irqrestore(&lpbfifo.lock, flags); - - /* Spinlock is released; it is now safe to call the callback */ - if (do_callback && req->callback) - req->callback(req); - - return IRQ_HANDLED; -} - -/** - * mpc52xx_lpbfifo_bcom_irq - IRQ handler for LPB FIFO Bestcomm task - * @irq: IRQ number to be handled - * @dev_id: device ID cookie - * - * Only used when receiving data. - * - * Return: irqreturn code (%IRQ_HANDLED) - */ -static irqreturn_t mpc52xx_lpbfifo_bcom_irq(int irq, void *dev_id) -{ - struct mpc52xx_lpbfifo_request *req; - unsigned long flags; - u32 status; - u32 ts; - - spin_lock_irqsave(&lpbfifo.lock, flags); - ts = mftb(); - - req = lpbfifo.req; - if (!req || (req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA)) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - return IRQ_HANDLED; - } - - if (irq != 0) /* don't increment on polled case */ - req->irq_count++; - - if (!bcom_buffer_done(lpbfifo.bcom_cur_task)) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - - req->buffer_not_done_cnt++; - if ((req->buffer_not_done_cnt % 1000) == 0) - pr_err("transfer stalled\n"); - - return IRQ_HANDLED; - } - - bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL); - - req->last_byte = ((u8 *)req->data)[req->size - 1]; - - req->pos = status & 0x00ffffff; - - /* Mark the FIFO as idle */ - lpbfifo.req = NULL; - - /* Release the lock before calling out to the callback. */ - req->irq_ticks += mftb() - ts; - spin_unlock_irqrestore(&lpbfifo.lock, flags); - - if (req->callback) - req->callback(req); - - return IRQ_HANDLED; -} - -/** - * mpc52xx_lpbfifo_poll - Poll for DMA completion - */ -void mpc52xx_lpbfifo_poll(void) -{ - struct mpc52xx_lpbfifo_request *req = lpbfifo.req; - int dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA); - int write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE; - - /* - * For more information, see comments on the "Fat Lady" - */ - if (dma && write) - mpc52xx_lpbfifo_irq(0, NULL); - else - mpc52xx_lpbfifo_bcom_irq(0, NULL); -} -EXPORT_SYMBOL(mpc52xx_lpbfifo_poll); - -/** - * mpc52xx_lpbfifo_submit - Submit an LPB FIFO transfer request. - * @req: Pointer to request structure - * - * Return: %0 on success, -errno code on error - */ -int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req) -{ - unsigned long flags; - - if (!lpbfifo.regs) - return -ENODEV; - - spin_lock_irqsave(&lpbfifo.lock, flags); - - /* If the req pointer is already set, then a transfer is in progress */ - if (lpbfifo.req) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - return -EBUSY; - } - - /* Setup the transfer */ - lpbfifo.req = req; - req->irq_count = 0; - req->irq_ticks = 0; - req->buffer_not_done_cnt = 0; - req->pos = 0; - - mpc52xx_lpbfifo_kick(req); - spin_unlock_irqrestore(&lpbfifo.lock, flags); - return 0; -} -EXPORT_SYMBOL(mpc52xx_lpbfifo_submit); - -int mpc52xx_lpbfifo_start_xfer(struct mpc52xx_lpbfifo_request *req) -{ - unsigned long flags; - - if (!lpbfifo.regs) - return -ENODEV; - - spin_lock_irqsave(&lpbfifo.lock, flags); - - /* - * If the req pointer is already set and a transfer was - * started on submit, then this transfer is in progress - */ - if (lpbfifo.req && !lpbfifo.req->defer_xfer_start) { - spin_unlock_irqrestore(&lpbfifo.lock, flags); - return -EBUSY; - } - - /* - * If the req was previously submitted but not - * started, start it now - */ - if (lpbfifo.req && lpbfifo.req == req && - lpbfifo.req->defer_xfer_start) { - out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01); - } - - spin_unlock_irqrestore(&lpbfifo.lock, flags); - return 0; -} -EXPORT_SYMBOL(mpc52xx_lpbfifo_start_xfer); - -void mpc52xx_lpbfifo_abort(struct mpc52xx_lpbfifo_request *req) -{ - unsigned long flags; - - spin_lock_irqsave(&lpbfifo.lock, flags); - if (lpbfifo.req == req) { - /* Put it into reset and clear the state */ - bcom_gen_bd_rx_reset(lpbfifo.bcom_rx_task); - bcom_gen_bd_tx_reset(lpbfifo.bcom_tx_task); - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000); - lpbfifo.req = NULL; - } - spin_unlock_irqrestore(&lpbfifo.lock, flags); -} -EXPORT_SYMBOL(mpc52xx_lpbfifo_abort); - -static int mpc52xx_lpbfifo_probe(struct platform_device *op) -{ - struct resource res; - int rc = -ENOMEM; - - if (lpbfifo.dev != NULL) - return -ENOSPC; - - lpbfifo.irq = irq_of_parse_and_map(op->dev.of_node, 0); - if (!lpbfifo.irq) - return -ENODEV; - - if (of_address_to_resource(op->dev.of_node, 0, &res)) - return -ENODEV; - lpbfifo.regs_phys = res.start; - lpbfifo.regs = of_iomap(op->dev.of_node, 0); - if (!lpbfifo.regs) - return -ENOMEM; - - spin_lock_init(&lpbfifo.lock); - - /* Put FIFO into reset */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000); - - /* Register the interrupt handler */ - rc = request_irq(lpbfifo.irq, mpc52xx_lpbfifo_irq, 0, - "mpc52xx-lpbfifo", &lpbfifo); - if (rc) - goto err_irq; - - /* Request the Bestcomm receive (fifo --> memory) task and IRQ */ - lpbfifo.bcom_rx_task = - bcom_gen_bd_rx_init(2, res.start + LPBFIFO_REG_FIFO_DATA, - BCOM_INITIATOR_SCLPC, BCOM_IPR_SCLPC, - 16*1024*1024); - if (!lpbfifo.bcom_rx_task) - goto err_bcom_rx; - - rc = request_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task), - mpc52xx_lpbfifo_bcom_irq, 0, - "mpc52xx-lpbfifo-rx", &lpbfifo); - if (rc) - goto err_bcom_rx_irq; - - lpbfifo.dma_irqs_enabled = 1; - - /* Request the Bestcomm transmit (memory --> fifo) task and IRQ */ - lpbfifo.bcom_tx_task = - bcom_gen_bd_tx_init(2, res.start + LPBFIFO_REG_FIFO_DATA, - BCOM_INITIATOR_SCLPC, BCOM_IPR_SCLPC); - if (!lpbfifo.bcom_tx_task) - goto err_bcom_tx; - - lpbfifo.dev = &op->dev; - return 0; - - err_bcom_tx: - free_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task), &lpbfifo); - err_bcom_rx_irq: - bcom_gen_bd_rx_release(lpbfifo.bcom_rx_task); - err_bcom_rx: - free_irq(lpbfifo.irq, &lpbfifo); - err_irq: - iounmap(lpbfifo.regs); - lpbfifo.regs = NULL; - - dev_err(&op->dev, "mpc52xx_lpbfifo_probe() failed\n"); - return -ENODEV; -} - - -static int mpc52xx_lpbfifo_remove(struct platform_device *op) -{ - if (lpbfifo.dev != &op->dev) - return 0; - - /* Put FIFO in reset */ - out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000); - - /* Release the bestcomm transmit task */ - free_irq(bcom_get_task_irq(lpbfifo.bcom_tx_task), &lpbfifo); - bcom_gen_bd_tx_release(lpbfifo.bcom_tx_task); - - /* Release the bestcomm receive task */ - free_irq(bcom_get_task_irq(lpbfifo.bcom_rx_task), &lpbfifo); - bcom_gen_bd_rx_release(lpbfifo.bcom_rx_task); - - free_irq(lpbfifo.irq, &lpbfifo); - iounmap(lpbfifo.regs); - lpbfifo.regs = NULL; - lpbfifo.dev = NULL; - - return 0; -} - -static const struct of_device_id mpc52xx_lpbfifo_match[] = { - { .compatible = "fsl,mpc5200-lpbfifo", }, - {}, -}; -MODULE_DEVICE_TABLE(of, mpc52xx_lpbfifo_match); - -static struct platform_driver mpc52xx_lpbfifo_driver = { - .driver = { - .name = "mpc52xx-lpbfifo", - .of_match_table = mpc52xx_lpbfifo_match, - }, - .probe = mpc52xx_lpbfifo_probe, - .remove = mpc52xx_lpbfifo_remove, -}; -module_platform_driver(mpc52xx_lpbfifo_driver); |