diff options
Diffstat (limited to 'drivers/spi/spi-meson-spicc.c')
| -rw-r--r-- | drivers/spi/spi-meson-spicc.c | 204 |
1 files changed, 164 insertions, 40 deletions
diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c index ba70ef94a82a..bd434d9055d9 100644 --- a/drivers/spi/spi-meson-spicc.c +++ b/drivers/spi/spi-meson-spicc.c @@ -116,6 +116,9 @@ #define SPICC_DWADDR 0x24 /* Write Address of DMA */ #define SPICC_ENH_CTL0 0x38 /* Enhanced Feature */ +#define SPICC_ENH_CLK_CS_DELAY_MASK GENMASK(15, 0) +#define SPICC_ENH_DATARATE_MASK GENMASK(23, 16) +#define SPICC_ENH_DATARATE_EN BIT(24) #define SPICC_ENH_MOSI_OEN BIT(25) #define SPICC_ENH_CLK_OEN BIT(26) #define SPICC_ENH_CS_OEN BIT(27) @@ -130,6 +133,7 @@ struct meson_spicc_data { bool has_oen; + bool has_enhance_clk_div; }; struct meson_spicc_device { @@ -137,6 +141,7 @@ struct meson_spicc_device { struct platform_device *pdev; void __iomem *base; struct clk *core; + struct clk *clk; struct spi_message *message; struct spi_transfer *xfer; const struct meson_spicc_data *data; @@ -322,40 +327,6 @@ static irqreturn_t meson_spicc_irq(int irq, void *data) return IRQ_HANDLED; } -static u32 meson_spicc_setup_speed(struct meson_spicc_device *spicc, u32 conf, - u32 speed) -{ - unsigned long parent, value; - unsigned int i, div; - - parent = clk_get_rate(spicc->core); - - /* Find closest inferior/equal possible speed */ - for (i = 0 ; i < 7 ; ++i) { - /* 2^(data_rate+2) */ - value = parent >> (i + 2); - - if (value <= speed) - break; - } - - /* If provided speed it lower than max divider, use max divider */ - if (i > 7) { - div = 7; - dev_warn_once(&spicc->pdev->dev, "unable to get close to speed %u\n", - speed); - } else - div = i; - - dev_dbg(&spicc->pdev->dev, "parent %lu, speed %u -> %lu (%u)\n", - parent, speed, value, div); - - conf &= ~SPICC_DATARATE_MASK; - conf |= FIELD_PREP(SPICC_DATARATE_MASK, div); - - return conf; -} - static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, struct spi_transfer *xfer) { @@ -364,9 +335,6 @@ static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, /* Read original configuration */ conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG); - /* Select closest divider */ - conf = meson_spicc_setup_speed(spicc, conf, xfer->speed_hz); - /* Setup word width */ conf &= ~SPICC_BITLENGTH_MASK; conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, @@ -375,6 +343,8 @@ static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, /* Ignore if unchanged */ if (conf != conf_orig) writel_relaxed(conf, spicc->base + SPICC_CONREG); + + clk_set_rate(spicc->clk, xfer->speed_hz); } static int meson_spicc_transfer_one(struct spi_master *master, @@ -481,9 +451,6 @@ static int meson_spicc_unprepare_transfer(struct spi_master *master) /* Disable all IRQs */ writel(0, spicc->base + SPICC_INTREG); - /* Disable controller */ - writel_bits_relaxed(SPICC_ENABLE, 0, spicc->base + SPICC_CONREG); - device_reset_optional(&spicc->pdev->dev); return 0; @@ -502,6 +469,152 @@ static void meson_spicc_cleanup(struct spi_device *spi) spi->controller_state = NULL; } +/* + * The Clock Mux + * x-----------------x x------------x x------\ + * |---| pow2 fixed div |---| pow2 div |----| | + * | x-----------------x x------------x | | + * src ---| | mux |-- out + * | x-----------------x x------------x | | + * |---| enh fixed div |---| enh div |0---| | + * x-----------------x x------------x x------/ + * + * Clk path for GX series: + * src -> pow2 fixed div -> pow2 div -> out + * + * Clk path for AXG series: + * src -> pow2 fixed div -> pow2 div -> mux -> out + * src -> enh fixed div -> enh div -> mux -> out + */ + +static int meson_spicc_clk_init(struct meson_spicc_device *spicc) +{ + struct device *dev = &spicc->pdev->dev; + struct clk_fixed_factor *pow2_fixed_div, *enh_fixed_div; + struct clk_divider *pow2_div, *enh_div; + struct clk_mux *mux; + struct clk_init_data init; + struct clk *clk; + struct clk_parent_data parent_data[2]; + char name[64]; + + memset(&init, 0, sizeof(init)); + memset(&parent_data, 0, sizeof(parent_data)); + + init.parent_data = parent_data; + + /* algorithm for pow2 div: rate = freq / 4 / (2 ^ N) */ + + pow2_fixed_div = devm_kzalloc(dev, sizeof(*pow2_fixed_div), GFP_KERNEL); + if (!pow2_fixed_div) + return -ENOMEM; + + snprintf(name, sizeof(name), "%s#pow2_fixed_div", dev_name(dev)); + init.name = name; + init.ops = &clk_fixed_factor_ops; + init.flags = 0; + parent_data[0].hw = __clk_get_hw(spicc->core); + init.num_parents = 1; + + pow2_fixed_div->mult = 1, + pow2_fixed_div->div = 4, + pow2_fixed_div->hw.init = &init; + + clk = devm_clk_register(dev, &pow2_fixed_div->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + pow2_div = devm_kzalloc(dev, sizeof(*pow2_div), GFP_KERNEL); + if (!pow2_div) + return -ENOMEM; + + snprintf(name, sizeof(name), "%s#pow2_div", dev_name(dev)); + init.name = name; + init.ops = &clk_divider_ops; + init.flags = CLK_SET_RATE_PARENT; + parent_data[0].hw = &pow2_fixed_div->hw; + init.num_parents = 1; + + pow2_div->shift = 16, + pow2_div->width = 3, + pow2_div->flags = CLK_DIVIDER_POWER_OF_TWO, + pow2_div->reg = spicc->base + SPICC_CONREG; + pow2_div->hw.init = &init; + + clk = devm_clk_register(dev, &pow2_div->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + if (!spicc->data->has_enhance_clk_div) { + spicc->clk = clk; + return 0; + } + + /* algorithm for enh div: rate = freq / 2 / (N + 1) */ + + enh_fixed_div = devm_kzalloc(dev, sizeof(*enh_fixed_div), GFP_KERNEL); + if (!enh_fixed_div) + return -ENOMEM; + + snprintf(name, sizeof(name), "%s#enh_fixed_div", dev_name(dev)); + init.name = name; + init.ops = &clk_fixed_factor_ops; + init.flags = 0; + parent_data[0].hw = __clk_get_hw(spicc->core); + init.num_parents = 1; + + enh_fixed_div->mult = 1, + enh_fixed_div->div = 2, + enh_fixed_div->hw.init = &init; + + clk = devm_clk_register(dev, &enh_fixed_div->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + enh_div = devm_kzalloc(dev, sizeof(*enh_div), GFP_KERNEL); + if (!enh_div) + return -ENOMEM; + + snprintf(name, sizeof(name), "%s#enh_div", dev_name(dev)); + init.name = name; + init.ops = &clk_divider_ops; + init.flags = CLK_SET_RATE_PARENT; + parent_data[0].hw = &enh_fixed_div->hw; + init.num_parents = 1; + + enh_div->shift = 16, + enh_div->width = 8, + enh_div->reg = spicc->base + SPICC_ENH_CTL0; + enh_div->hw.init = &init; + + clk = devm_clk_register(dev, &enh_div->hw); + if (WARN_ON(IS_ERR(clk))) + return PTR_ERR(clk); + + mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL); + if (!mux) + return -ENOMEM; + + snprintf(name, sizeof(name), "%s#sel", dev_name(dev)); + init.name = name; + init.ops = &clk_mux_ops; + parent_data[0].hw = &pow2_div->hw; + parent_data[1].hw = &enh_div->hw; + init.num_parents = 2; + init.flags = CLK_SET_RATE_PARENT; + + mux->mask = 0x1, + mux->shift = 24, + mux->reg = spicc->base + SPICC_ENH_CTL0; + mux->hw.init = &init; + + spicc->clk = devm_clk_register(dev, &mux->hw); + if (WARN_ON(IS_ERR(spicc->clk))) + return PTR_ERR(spicc->clk); + + return 0; +} + static int meson_spicc_probe(struct platform_device *pdev) { struct spi_master *master; @@ -533,6 +646,10 @@ static int meson_spicc_probe(struct platform_device *pdev) goto out_master; } + /* Set master mode and enable controller */ + writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER, + spicc->base + SPICC_CONREG); + /* Disable all IRQs */ writel_relaxed(0, spicc->base + SPICC_INTREG); @@ -584,6 +701,12 @@ static int meson_spicc_probe(struct platform_device *pdev) meson_spicc_oen_enable(spicc); + ret = meson_spicc_clk_init(spicc); + if (ret) { + dev_err(&pdev->dev, "clock registration failed\n"); + goto out_master; + } + ret = devm_spi_register_master(&pdev->dev, master); if (ret) { dev_err(&pdev->dev, "spi master registration failed\n"); @@ -618,6 +741,7 @@ static const struct meson_spicc_data meson_spicc_gx_data = { static const struct meson_spicc_data meson_spicc_axg_data = { .has_oen = true, + .has_enhance_clk_div = true, }; static const struct of_device_id meson_spicc_of_match[] = { |