diff options
Diffstat (limited to 'drivers/clk/clk-axi-clkgen.c')
| -rw-r--r-- | drivers/clk/clk-axi-clkgen.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c new file mode 100644 index 00000000000..8137327847c --- /dev/null +++ b/drivers/clk/clk-axi-clkgen.c @@ -0,0 +1,331 @@ +/* + * AXI clkgen driver + * + * Copyright 2012-2013 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + * + */ + +#include <linux/platform_device.h> +#include <linux/clk-provider.h> +#include <linux/clk.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/err.h> + +#define AXI_CLKGEN_REG_UPDATE_ENABLE 0x04 +#define AXI_CLKGEN_REG_CLK_OUT1 0x08 +#define AXI_CLKGEN_REG_CLK_OUT2 0x0c +#define AXI_CLKGEN_REG_CLK_DIV 0x10 +#define AXI_CLKGEN_REG_CLK_FB1 0x14 +#define AXI_CLKGEN_REG_CLK_FB2 0x18 +#define AXI_CLKGEN_REG_LOCK1 0x1c +#define AXI_CLKGEN_REG_LOCK2 0x20 +#define AXI_CLKGEN_REG_LOCK3 0x24 +#define AXI_CLKGEN_REG_FILTER1 0x28 +#define AXI_CLKGEN_REG_FILTER2 0x2c + +struct axi_clkgen { + void __iomem *base; + struct clk_hw clk_hw; +}; + +static uint32_t axi_clkgen_lookup_filter(unsigned int m) +{ + switch (m) { + case 0: + return 0x01001990; + case 1: + return 0x01001190; + case 2: + return 0x01009890; + case 3: + return 0x01001890; + case 4: + return 0x01008890; + case 5 ... 8: + return 0x01009090; + case 9 ... 11: + return 0x01000890; + case 12: + return 0x08009090; + case 13 ... 22: + return 0x01001090; + case 23 ... 36: + return 0x01008090; + case 37 ... 46: + return 0x08001090; + default: + return 0x08008090; + } +} + +static const uint32_t axi_clkgen_lock_table[] = { + 0x060603e8, 0x060603e8, 0x080803e8, 0x0b0b03e8, + 0x0e0e03e8, 0x111103e8, 0x131303e8, 0x161603e8, + 0x191903e8, 0x1c1c03e8, 0x1f1f0384, 0x1f1f0339, + 0x1f1f02ee, 0x1f1f02bc, 0x1f1f028a, 0x1f1f0271, + 0x1f1f023f, 0x1f1f0226, 0x1f1f020d, 0x1f1f01f4, + 0x1f1f01db, 0x1f1f01c2, 0x1f1f01a9, 0x1f1f0190, + 0x1f1f0190, 0x1f1f0177, 0x1f1f015e, 0x1f1f015e, + 0x1f1f0145, 0x1f1f0145, 0x1f1f012c, 0x1f1f012c, + 0x1f1f012c, 0x1f1f0113, 0x1f1f0113, 0x1f1f0113, +}; + +static uint32_t axi_clkgen_lookup_lock(unsigned int m) +{ + if (m < ARRAY_SIZE(axi_clkgen_lock_table)) + return axi_clkgen_lock_table[m]; + return 0x1f1f00fa; +} + +static const unsigned int fpfd_min = 10000; +static const unsigned int fpfd_max = 300000; +static const unsigned int fvco_min = 600000; +static const unsigned int fvco_max = 1200000; + +static void axi_clkgen_calc_params(unsigned long fin, unsigned long fout, + unsigned int *best_d, unsigned int *best_m, unsigned int *best_dout) +{ + unsigned long d, d_min, d_max, _d_min, _d_max; + unsigned long m, m_min, m_max; + unsigned long f, dout, best_f, fvco; + + fin /= 1000; + fout /= 1000; + + best_f = ULONG_MAX; + *best_d = 0; + *best_m = 0; + *best_dout = 0; + + d_min = max_t(unsigned long, DIV_ROUND_UP(fin, fpfd_max), 1); + d_max = min_t(unsigned long, fin / fpfd_min, 80); + + m_min = max_t(unsigned long, DIV_ROUND_UP(fvco_min, fin) * d_min, 1); + m_max = min_t(unsigned long, fvco_max * d_max / fin, 64); + + for (m = m_min; m <= m_max; m++) { + _d_min = max(d_min, DIV_ROUND_UP(fin * m, fvco_max)); + _d_max = min(d_max, fin * m / fvco_min); + + for (d = _d_min; d <= _d_max; d++) { + fvco = fin * m / d; + + dout = DIV_ROUND_CLOSEST(fvco, fout); + dout = clamp_t(unsigned long, dout, 1, 128); + f = fvco / dout; + if (abs(f - fout) < abs(best_f - fout)) { + best_f = f; + *best_d = d; + *best_m = m; + *best_dout = dout; + if (best_f == fout) + return; + } + } + } +} + +static void axi_clkgen_calc_clk_params(unsigned int divider, unsigned int *low, + unsigned int *high, unsigned int *edge, unsigned int *nocount) +{ + if (divider == 1) + *nocount = 1; + else + *nocount = 0; + + *high = divider / 2; + *edge = divider % 2; + *low = divider - *high; +} + +static void axi_clkgen_write(struct axi_clkgen *axi_clkgen, + unsigned int reg, unsigned int val) +{ + writel(val, axi_clkgen->base + reg); +} + +static void axi_clkgen_read(struct axi_clkgen *axi_clkgen, + unsigned int reg, unsigned int *val) +{ + *val = readl(axi_clkgen->base + reg); +} + +static struct axi_clkgen *clk_hw_to_axi_clkgen(struct clk_hw *clk_hw) +{ + return container_of(clk_hw, struct axi_clkgen, clk_hw); +} + +static int axi_clkgen_set_rate(struct clk_hw *clk_hw, + unsigned long rate, unsigned long parent_rate) +{ + struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); + unsigned int d, m, dout; + unsigned int nocount; + unsigned int high; + unsigned int edge; + unsigned int low; + uint32_t filter; + uint32_t lock; + + if (parent_rate == 0 || rate == 0) + return -EINVAL; + + axi_clkgen_calc_params(parent_rate, rate, &d, &m, &dout); + + if (d == 0 || dout == 0 || m == 0) + return -EINVAL; + + filter = axi_clkgen_lookup_filter(m - 1); + lock = axi_clkgen_lookup_lock(m - 1); + + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_UPDATE_ENABLE, 0); + + axi_clkgen_calc_clk_params(dout, &low, &high, &edge, &nocount); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT1, + (high << 6) | low); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT2, + (edge << 7) | (nocount << 6)); + + axi_clkgen_calc_clk_params(d, &low, &high, &edge, &nocount); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_DIV, + (edge << 13) | (nocount << 12) | (high << 6) | low); + + axi_clkgen_calc_clk_params(m, &low, &high, &edge, &nocount); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_FB1, + (high << 6) | low); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_CLK_FB2, + (edge << 7) | (nocount << 6)); + + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK1, lock & 0x3ff); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK2, + (((lock >> 16) & 0x1f) << 10) | 0x1); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_LOCK3, + (((lock >> 24) & 0x1f) << 10) | 0x3e9); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_FILTER1, filter >> 16); + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_FILTER2, filter); + + axi_clkgen_write(axi_clkgen, AXI_CLKGEN_REG_UPDATE_ENABLE, 1); + + return 0; +} + +static long axi_clkgen_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned int d, m, dout; + + axi_clkgen_calc_params(*parent_rate, rate, &d, &m, &dout); + + if (d == 0 || dout == 0 || m == 0) + return -EINVAL; + + return *parent_rate / d * m / dout; +} + +static unsigned long axi_clkgen_recalc_rate(struct clk_hw *clk_hw, + unsigned long parent_rate) +{ + struct axi_clkgen *axi_clkgen = clk_hw_to_axi_clkgen(clk_hw); + unsigned int d, m, dout; + unsigned int reg; + unsigned long long tmp; + + axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_OUT1, ®); + dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); + axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_DIV, ®); + d = (reg & 0x3f) + ((reg >> 6) & 0x3f); + axi_clkgen_read(axi_clkgen, AXI_CLKGEN_REG_CLK_FB1, ®); + m = (reg & 0x3f) + ((reg >> 6) & 0x3f); + + if (d == 0 || dout == 0) + return 0; + + tmp = (unsigned long long)(parent_rate / d) * m; + do_div(tmp, dout); + + if (tmp > ULONG_MAX) + return ULONG_MAX; + + return tmp; +} + +static const struct clk_ops axi_clkgen_ops = { + .recalc_rate = axi_clkgen_recalc_rate, + .round_rate = axi_clkgen_round_rate, + .set_rate = axi_clkgen_set_rate, +}; + +static int axi_clkgen_probe(struct platform_device *pdev) +{ + struct axi_clkgen *axi_clkgen; + struct clk_init_data init; + const char *parent_name; + const char *clk_name; + struct resource *mem; + struct clk *clk; + + axi_clkgen = devm_kzalloc(&pdev->dev, sizeof(*axi_clkgen), GFP_KERNEL); + if (!axi_clkgen) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + axi_clkgen->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(axi_clkgen->base)) + return PTR_ERR(axi_clkgen->base); + + parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0); + if (!parent_name) + return -EINVAL; + + clk_name = pdev->dev.of_node->name; + of_property_read_string(pdev->dev.of_node, "clock-output-names", + &clk_name); + + init.name = clk_name; + init.ops = &axi_clkgen_ops; + init.flags = 0; + init.parent_names = &parent_name; + init.num_parents = 1; + + axi_clkgen->clk_hw.init = &init; + clk = devm_clk_register(&pdev->dev, &axi_clkgen->clk_hw); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + return of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, + clk); +} + +static int axi_clkgen_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + + return 0; +} + +static const struct of_device_id axi_clkgen_ids[] = { + { .compatible = "adi,axi-clkgen-1.00.a" }, + { }, +}; +MODULE_DEVICE_TABLE(of, axi_clkgen_ids); + +static struct platform_driver axi_clkgen_driver = { + .driver = { + .name = "adi-axi-clkgen", + .owner = THIS_MODULE, + .of_match_table = axi_clkgen_ids, + }, + .probe = axi_clkgen_probe, + .remove = axi_clkgen_remove, +}; +module_platform_driver(axi_clkgen_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Driver for the Analog Devices' AXI clkgen pcore clock generator"); |