| /* |
| * 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"); |