diff options
Diffstat (limited to 'drivers/spi/spi-fsl-spi.c')
| -rw-r--r-- | drivers/spi/spi-fsl-spi.c | 89 |
1 files changed, 66 insertions, 23 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 8f2e97857e8b..1d9b33aa1a3b 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Freescale SPI controller driver. * @@ -13,11 +14,6 @@ * GRLIB support: * Copyright (c) 2012 Aeroflex Gaisler AB. * Author: Andreas Larsson <andreas@gaisler.com> - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2 of the License, or (at your - * option) any later version. */ #include <linux/delay.h> #include <linux/dma-mapping.h> @@ -39,6 +35,14 @@ #include <linux/spi/spi_bitbang.h> #include <linux/types.h> +#ifdef CONFIG_FSL_SOC +#include <sysdev/fsl_soc.h> +#endif + +/* Specific to the MPC8306/MPC8309 */ +#define IMMR_SPI_CS_OFFSET 0x14c +#define SPI_BOOT_SEL_BIT 0x80000000 + #include "spi-fsl-lib.h" #include "spi-fsl-cpm.h" #include "spi-fsl-spi.h" @@ -355,33 +359,50 @@ static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t, static int fsl_spi_do_one_msg(struct spi_master *master, struct spi_message *m) { + struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master); struct spi_device *spi = m->spi; struct spi_transfer *t, *first; unsigned int cs_change; const int nsecs = 50; - int status; + int status, last_bpw; + + /* + * In CPU mode, optimize large byte transfers to use larger + * bits_per_word values to reduce number of interrupts taken. + */ + if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) { + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->len < 256 || t->bits_per_word != 8) + continue; + if ((t->len & 3) == 0) + t->bits_per_word = 32; + else if ((t->len & 1) == 0) + t->bits_per_word = 16; + } + } /* Don't allow changes if CS is active */ - first = list_first_entry(&m->transfers, struct spi_transfer, - transfer_list); + cs_change = 1; list_for_each_entry(t, &m->transfers, transfer_list) { - if ((first->bits_per_word != t->bits_per_word) || - (first->speed_hz != t->speed_hz)) { + if (cs_change) + first = t; + cs_change = t->cs_change; + if (first->speed_hz != t->speed_hz) { dev_err(&spi->dev, - "bits_per_word/speed_hz should be same for the same SPI transfer\n"); + "speed_hz cannot change while CS is active\n"); return -EINVAL; } } + last_bpw = -1; cs_change = 1; status = -EINVAL; list_for_each_entry(t, &m->transfers, transfer_list) { - if (t->bits_per_word || t->speed_hz) { - if (cs_change) - status = fsl_spi_setup_transfer(spi, t); - if (status < 0) - break; - } + if (cs_change || last_bpw != t->bits_per_word) + status = fsl_spi_setup_transfer(spi, t); + if (status < 0) + break; + last_bpw = t->bits_per_word; if (cs_change) { fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE); @@ -407,7 +428,6 @@ static int fsl_spi_do_one_msg(struct spi_master *master, } m->status = status; - spi_finalize_current_message(master); if (status || !cs_change) { ndelay(nsecs); @@ -415,6 +435,7 @@ static int fsl_spi_do_one_msg(struct spi_master *master, } fsl_spi_setup_transfer(spi, NULL); + spi_finalize_current_message(master); return 0; } @@ -701,10 +722,17 @@ static void fsl_spi_cs_control(struct spi_device *spi, bool on) struct fsl_spi_platform_data *pdata = dev_get_platdata(dev); struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata); u16 cs = spi->chip_select; - int gpio = pinfo->gpios[cs]; - bool alow = pinfo->alow_flags[cs]; - gpio_set_value(gpio, on ^ alow); + if (cs < pinfo->ngpios) { + int gpio = pinfo->gpios[cs]; + bool alow = pinfo->alow_flags[cs]; + + gpio_set_value(gpio, on ^ alow); + } else { + if (WARN_ON_ONCE(cs > pinfo->ngpios || !pinfo->immr_spi_cs)) + return; + iowrite32be(on ? SPI_BOOT_SEL_BIT : 0, pinfo->immr_spi_cs); + } } static int of_fsl_spi_get_chipselects(struct device *dev) @@ -712,12 +740,15 @@ static int of_fsl_spi_get_chipselects(struct device *dev) struct device_node *np = dev->of_node; struct fsl_spi_platform_data *pdata = dev_get_platdata(dev); struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata); + bool spisel_boot = IS_ENABLED(CONFIG_FSL_SOC) && + of_property_read_bool(np, "fsl,spisel_boot"); int ngpios; int i = 0; int ret; ngpios = of_gpio_count(np); - if (ngpios <= 0) { + ngpios = max(ngpios, 0); + if (ngpios == 0 && !spisel_boot) { /* * SPI w/o chip-select line. One SPI device is still permitted * though. @@ -726,6 +757,7 @@ static int of_fsl_spi_get_chipselects(struct device *dev) return 0; } + pinfo->ngpios = ngpios; pinfo->gpios = kmalloc_array(ngpios, sizeof(*pinfo->gpios), GFP_KERNEL); if (!pinfo->gpios) @@ -769,7 +801,18 @@ static int of_fsl_spi_get_chipselects(struct device *dev) } } - pdata->max_chipselect = ngpios; +#if IS_ENABLED(CONFIG_FSL_SOC) + if (spisel_boot) { + pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4); + if (!pinfo->immr_spi_cs) { + ret = -ENOMEM; + i = ngpios - 1; + goto err_loop; + } + } +#endif + + pdata->max_chipselect = ngpios + spisel_boot; pdata->cs_control = fsl_spi_cs_control; return 0; |