[PATCH v2 2/2] spi: spi-ti-qspi: Add checking which flash chip has been mmap-ed

From: Arkadiusz Kwiatkowski
Date: Fri Mar 30 2018 - 05:56:49 EST


This patch allows placing more than one flash chip on the qspi bus
by checking which spi device has been memory-mapped and remapping
if necessary.

Signed-off-by: Arkadiusz Kwiatkowski <arkadiusz.kwiatkowski@xxxxxxxxx>
---
drivers/spi/spi-ti-qspi.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index d0ea62d..5b99a1e 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -66,7 +66,7 @@ struct ti_qspi {
u32 cmd;
u32 dc;

- bool mmap_enabled;
+ struct spi_device *mmap_spi_device;
};

#define QSPI_PID (0x0)
@@ -493,7 +493,7 @@ static void ti_qspi_enable_memory_map(struct spi_device *spi)
MEM_CS_MASK,
MEM_CS_EN(spi->chip_select));
}
- qspi->mmap_enabled = true;
+ qspi->mmap_spi_device = spi;
}

static void ti_qspi_disable_memory_map(struct spi_device *spi)
@@ -504,7 +504,7 @@ static void ti_qspi_disable_memory_map(struct spi_device *spi)
if (qspi->ctrl_base)
regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
MEM_CS_MASK, 0);
- qspi->mmap_enabled = false;
+ qspi->mmap_spi_device = NULL;
}

static void ti_qspi_setup_mmap_read(struct spi_device *spi,
@@ -544,8 +544,12 @@ static int ti_qspi_spi_flash_read(struct spi_device *spi,

mutex_lock(&qspi->list_lock);

- if (!qspi->mmap_enabled)
+ if (qspi->mmap_spi_device != spi) {
+ if (qspi->mmap_spi_device)
+ ti_qspi_disable_memory_map(qspi->mmap_spi_device);
ti_qspi_enable_memory_map(spi);
+ }
+
ti_qspi_setup_mmap_read(spi, msg);

if (qspi->rx_chan) {
@@ -600,7 +604,7 @@ static int ti_qspi_start_transfer_one(struct spi_master *master,

mutex_lock(&qspi->list_lock);

- if (qspi->mmap_enabled)
+ if (qspi->mmap_spi_device)
ti_qspi_disable_memory_map(spi);

list_for_each_entry(t, &m->transfers, transfer_list) {
@@ -787,7 +791,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
master->spi_flash_read = NULL;
}
}
- qspi->mmap_enabled = false;
+ qspi->mmap_spi_device = NULL;

ret = devm_spi_register_master(&pdev->dev, master);
if (!ret)
--
2.7.4

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