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spi/pl022: add support for the PL023 derivate
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This adds support for a further ST variant of the PL022 called
PL023. Some differences in the control registers due to being
stripped down to SPI mode only, and a new clock feedback sample
delay config setting is available.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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Linus Walleij authored and Grant Likely committed May 25, 2010
1 parent 556f4ae commit 781c7b1
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Showing 2 changed files with 104 additions and 18 deletions.
90 changes: 74 additions & 16 deletions drivers/spi/amba-pl022.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -135,6 +135,8 @@
#define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6)
#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
/* This one is only in the PL023 variant */
#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)

/*
* SSP Status Register - SSP_SR
Expand Down Expand Up @@ -317,12 +319,14 @@ enum ssp_writing {
* @unidir: supports unidirection transfers
* @extended_cr: 32 bit wide control register 0 with extra
* features and extra features in CR1 as found in the ST variants
* @pl023: supports a subset of the ST extensions called "PL023"
*/
struct vendor_data {
int fifodepth;
int max_bpw;
bool unidir;
bool extended_cr;
bool pl023;
};

/**
Expand Down Expand Up @@ -541,11 +545,6 @@ static void restore_state(struct pl022 *pl022)
writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
}

/**
* load_ssp_default_config - Load default configuration for SSP
* @pl022: SSP driver private data structure
*/

/*
* Default SSP Register Values
*/
Expand All @@ -568,6 +567,14 @@ static void restore_state(struct pl022 *pl022)
GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
)

/* The PL023 version is slightly different again */
#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
)

#define DEFAULT_SSP_REG_CR1 ( \
GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
Expand All @@ -585,6 +592,20 @@ static void restore_state(struct pl022 *pl022)
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
)

/*
* The PL023 variant has further differences: no loopback mode, no microwire
* support, and a new clock feedback delay setting.
*/
#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
)

#define DEFAULT_SSP_REG_CPSR ( \
GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
Expand All @@ -595,10 +616,16 @@ static void restore_state(struct pl022 *pl022)
GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
)


/**
* load_ssp_default_config - Load default configuration for SSP
* @pl022: SSP driver private data structure
*/
static void load_ssp_default_config(struct pl022 *pl022)
{
if (pl022->vendor->extended_cr) {
if (pl022->vendor->pl023) {
writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
} else if (pl022->vendor->extended_cr) {
writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
} else {
Expand Down Expand Up @@ -1629,20 +1656,27 @@ static int pl022_setup(struct spi_device *spi)

/* Special setup for the ST micro extended control registers */
if (pl022->vendor->extended_cr) {
if (pl022->vendor->pl023) {
/* These bits are only in the PL023 */
SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
SSP_CR1_MASK_FBCLKDEL_ST, 13);
} else {
/* These bits are in the PL022 but not PL023 */
SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
SSP_CR0_MASK_HALFDUP_ST, 5);
SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
SSP_CR0_MASK_CSS_ST, 16);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF_ST, 21);
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
SSP_CR1_MASK_MWAIT_ST, 6);
}
SSP_WRITE_BITS(chip->cr0, chip_info->data_size,
SSP_CR0_MASK_DSS_ST, 0);
SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
SSP_CR0_MASK_HALFDUP_ST, 5);
SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
SSP_CR0_MASK_CSS_ST, 16);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF_ST, 21);
SSP_WRITE_BITS(chip->cr1, chip_info->endian_rx,
SSP_CR1_MASK_RENDN_ST, 4);
SSP_WRITE_BITS(chip->cr1, chip_info->endian_tx,
SSP_CR1_MASK_TENDN_ST, 5);
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
SSP_CR1_MASK_MWAIT_ST, 6);
SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
SSP_CR1_MASK_RXIFLSEL_ST, 7);
SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
Expand All @@ -1657,7 +1691,9 @@ static int pl022_setup(struct spi_device *spi)
SSP_WRITE_BITS(chip->cr0, chip_info->clk_pol, SSP_CR0_MASK_SPO, 6);
SSP_WRITE_BITS(chip->cr0, chip_info->clk_phase, SSP_CR0_MASK_SPH, 7);
SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8);
SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0);
/* Loopback is available on all versions except PL023 */
if (!pl022->vendor->pl023)
SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0);
SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD, 3);
Expand Down Expand Up @@ -1874,6 +1910,7 @@ static struct vendor_data vendor_arm = {
.max_bpw = 16,
.unidir = false,
.extended_cr = false,
.pl023 = false,
};


Expand All @@ -1882,6 +1919,15 @@ static struct vendor_data vendor_st = {
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = false,
};

static struct vendor_data vendor_st_pl023 = {
.fifodepth = 32,
.max_bpw = 32,
.unidir = false,
.extended_cr = true,
.pl023 = true,
};

static struct amba_id pl022_ids[] = {
Expand All @@ -1903,6 +1949,18 @@ static struct amba_id pl022_ids[] = {
.mask = 0xffffffff,
.data = &vendor_st,
},
{
/*
* ST-Ericsson derivative "PL023" (this is not
* an official ARM number), this is a PL022 SSP block
* stripped to SPI mode only, it has 32bit wide
* and 32 locations deep TX/RX FIFO but no extended
* CR0/CR1 register
*/
.id = 0x00080023,
.mask = 0xffffffff,
.data = &vendor_st_pl023,
},
{ 0, 0 },
};

Expand Down
32 changes: 30 additions & 2 deletions include/linux/amba/pl022.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -182,8 +182,8 @@ enum ssp_microwire_wait_state {
};

/**
* enum Microwire - whether Full/Half Duplex, only available
* in the ST Micro variant.
* enum ssp_duplex - whether Full/Half Duplex on microwire, only
* available in the ST Micro variant.
* @SSP_MICROWIRE_CHANNEL_FULL_DUPLEX: SSPTXD becomes bi-directional,
* SSPRXD not used
* @SSP_MICROWIRE_CHANNEL_HALF_DUPLEX: SSPTXD is an output, SSPRXD is
Expand All @@ -194,6 +194,31 @@ enum ssp_duplex {
SSP_MICROWIRE_CHANNEL_HALF_DUPLEX
};

/**
* enum ssp_clkdelay - an optional clock delay on the feedback clock
* only available in the ST Micro PL023 variant.
* @SSP_FEEDBACK_CLK_DELAY_NONE: no delay, the data coming in from the
* slave is sampled directly
* @SSP_FEEDBACK_CLK_DELAY_1T: the incoming slave data is sampled with
* a delay of T-dt
* @SSP_FEEDBACK_CLK_DELAY_2T: dito with a delay if 2T-dt
* @SSP_FEEDBACK_CLK_DELAY_3T: dito with a delay if 3T-dt
* @SSP_FEEDBACK_CLK_DELAY_4T: dito with a delay if 4T-dt
* @SSP_FEEDBACK_CLK_DELAY_5T: dito with a delay if 5T-dt
* @SSP_FEEDBACK_CLK_DELAY_6T: dito with a delay if 6T-dt
* @SSP_FEEDBACK_CLK_DELAY_7T: dito with a delay if 7T-dt
*/
enum ssp_clkdelay {
SSP_FEEDBACK_CLK_DELAY_NONE,
SSP_FEEDBACK_CLK_DELAY_1T,
SSP_FEEDBACK_CLK_DELAY_2T,
SSP_FEEDBACK_CLK_DELAY_3T,
SSP_FEEDBACK_CLK_DELAY_4T,
SSP_FEEDBACK_CLK_DELAY_5T,
SSP_FEEDBACK_CLK_DELAY_6T,
SSP_FEEDBACK_CLK_DELAY_7T
};

/**
* CHIP select/deselect commands
*/
Expand Down Expand Up @@ -237,6 +262,8 @@ struct pl022_ssp_controller {
* @ctrl_len: Microwire interface: Control length
* @wait_state: Microwire interface: Wait state
* @duplex: Microwire interface: Full/Half duplex
* @clkdelay: on the PL023 variant, the delay in feeback clock cycles
* before sampling the incoming line
* @cs_control: function pointer to board-specific function to
* assert/deassert I/O port to control HW generation of devices chip-select.
* @dma_xfer_type: Type of DMA xfer (Mem-to-periph or Periph-to-Periph)
Expand All @@ -260,6 +287,7 @@ struct pl022_config_chip {
enum ssp_microwire_ctrl_len ctrl_len;
enum ssp_microwire_wait_state wait_state;
enum ssp_duplex duplex;
enum ssp_clkdelay clkdelay;
void (*cs_control) (u32 control);
};

Expand Down

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