From mboxrd@z Thu Jan 1 00:00:00 1970 From: mturquette@linaro.org (Mike Turquette) Date: Thu, 30 May 2013 12:42:27 -0700 Subject: [PATCHv4 3/6] ARM: socfpga: Add support to gate peripheral clocks In-Reply-To: <1369410080-436-3-git-send-email-dinguyen@altera.com> References: <1369410080-436-1-git-send-email-dinguyen@altera.com> <1369410080-436-3-git-send-email-dinguyen@altera.com> Message-ID: <20130530194227.4470.3741@quantum> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Quoting dinguyen at altera.com (2013-05-24 08:41:17) > From: Dinh Nguyen > > Add support to gate the clocks that directly feed peripherals. For clocks > with multiple parents, add the ability to determine the correct parent, > and also set parents. Also add support to calculate and set the clocks' > rate. > > Signed-off-by: Dinh Nguyen > Reviewed-by: Pavel Machek > CC: Mike Turquette > CC: Arnd Bergmann > CC: Olof Johansson > Cc: Pavel Machek > CC: > Looks OK to me. Lots of conditionals in socfpga_gate_clk_init, which some day might be better to break out into separate clk types. Not a big deal for now: Acked-by: Mike Turquette > v3: > - Addressed comments from Pavel > > v2: > - Fix space/indent errors > - Add streq for strcmp == 0 > --- > drivers/clk/socfpga/clk.c | 194 ++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 185 insertions(+), 9 deletions(-) > > diff --git a/drivers/clk/socfpga/clk.c b/drivers/clk/socfpga/clk.c > index bd11315..5bb848c 100644 > --- a/drivers/clk/socfpga/clk.c > +++ b/drivers/clk/socfpga/clk.c > @@ -24,15 +24,17 @@ > #include > > /* Clock Manager offsets */ > -#define CLKMGR_CTRL 0x0 > -#define CLKMGR_BYPASS 0x4 > +#define CLKMGR_CTRL 0x0 > +#define CLKMGR_BYPASS 0x4 > +#define CLKMGR_L4SRC 0x70 > +#define CLKMGR_PERPLL_SRC 0xAC > > /* Clock bypass bits */ > -#define MAINPLL_BYPASS (1<<0) > -#define SDRAMPLL_BYPASS (1<<1) > -#define SDRAMPLL_SRC_BYPASS (1<<2) > -#define PERPLL_BYPASS (1<<3) > -#define PERPLL_SRC_BYPASS (1<<4) > +#define MAINPLL_BYPASS (1<<0) > +#define SDRAMPLL_BYPASS (1<<1) > +#define SDRAMPLL_SRC_BYPASS (1<<2) > +#define PERPLL_BYPASS (1<<3) > +#define PERPLL_SRC_BYPASS (1<<4) > > #define SOCFPGA_PLL_BG_PWRDWN 0 > #define SOCFPGA_PLL_EXT_ENA 1 > @@ -41,6 +43,17 @@ > #define SOCFPGA_PLL_DIVF_SHIFT 3 > #define SOCFPGA_PLL_DIVQ_MASK 0x003F0000 > #define SOCFPGA_PLL_DIVQ_SHIFT 16 > +#define SOCFGPA_MAX_PARENTS 3 > + > +#define SOCFPGA_L4_MP_CLK "l4_mp_clk" > +#define SOCFPGA_L4_SP_CLK "l4_sp_clk" > +#define SOCFPGA_NAND_CLK "nand_clk" > +#define SOCFPGA_NAND_X_CLK "nand_x_clk" > +#define SOCFPGA_MMC_CLK "mmc_clk" > +#define SOCFPGA_DB_CLK "gpio_db_clk" > + > +#define div_mask(width) ((1 << (width)) - 1) > +#define streq(a, b) (strcmp((a), (b)) == 0) > > extern void __iomem *clk_mgr_base_addr; > > @@ -49,6 +62,9 @@ struct socfpga_clk { > char *parent_name; > char *clk_name; > u32 fixed_div; > + void __iomem *div_reg; > + u32 width; /* only valid if div_reg != 0 */ > + u32 shift; /* only valid if div_reg != 0 */ > }; > #define to_socfpga_clk(p) container_of(p, struct socfpga_clk, hw.hw) > > @@ -132,8 +148,9 @@ static __init struct clk *socfpga_clk_init(struct device_node *node, > > socfpga_clk->hw.hw.init = &init; > > - if (strcmp(clk_name, "main_pll") || strcmp(clk_name, "periph_pll") || > - strcmp(clk_name, "sdram_pll")) { > + if (streq(clk_name, "main_pll") || > + streq(clk_name, "periph_pll") || > + streq(clk_name, "sdram_pll")) { > socfpga_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA; > clk_pll_ops.enable = clk_gate_ops.enable; > clk_pll_ops.disable = clk_gate_ops.disable; > @@ -148,6 +165,159 @@ static __init struct clk *socfpga_clk_init(struct device_node *node, > return clk; > } > > +static u8 socfpga_clk_get_parent(struct clk_hw *hwclk) > +{ > + u32 l4_src; > + u32 perpll_src; > + > + if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) { > + l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC); > + return l4_src &= 0x1; > + } > + if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) { > + l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC); > + return !!(l4_src & 2); > + } > + > + perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC); > + if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) > + return perpll_src &= 0x3; > + if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) || > + streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) > + return (perpll_src >> 2) & 3; > + > + /* QSPI clock */ > + return (perpll_src >> 4) & 3; > + > +} > + > +static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent) > +{ > + u32 src_reg; > + > + if (streq(hwclk->init->name, SOCFPGA_L4_MP_CLK)) { > + src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC); > + src_reg &= ~0x1; > + src_reg |= parent; > + writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC); > + } else if (streq(hwclk->init->name, SOCFPGA_L4_SP_CLK)) { > + src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC); > + src_reg &= ~0x2; > + src_reg |= (parent << 1); > + writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC); > + } else { > + src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC); > + if (streq(hwclk->init->name, SOCFPGA_MMC_CLK)) { > + src_reg &= ~0x3; > + src_reg |= parent; > + } else if (streq(hwclk->init->name, SOCFPGA_NAND_CLK) || > + streq(hwclk->init->name, SOCFPGA_NAND_X_CLK)) { > + src_reg &= ~0xC; > + src_reg |= (parent << 2); > + } else {/* QSPI clock */ > + src_reg &= ~0x30; > + src_reg |= (parent << 4); > + } > + writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC); > + } > + > + return 0; > +} > + > +static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk, > + unsigned long parent_rate) > +{ > + struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk); > + u32 div = 1, val; > + > + if (socfpgaclk->fixed_div) > + div = socfpgaclk->fixed_div; > + else if (socfpgaclk->div_reg) { > + val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift; > + val &= div_mask(socfpgaclk->width); > + if (streq(hwclk->init->name, SOCFPGA_DB_CLK)) > + div = val + 1; > + else > + div = (1 << val); > + } > + > + return parent_rate / div; > +} > + > +static struct clk_ops gateclk_ops = { > + .recalc_rate = socfpga_clk_recalc_rate, > + .get_parent = socfpga_clk_get_parent, > + .set_parent = socfpga_clk_set_parent, > +}; > + > +static void __init socfpga_gate_clk_init(struct device_node *node, > + const struct clk_ops *ops) > +{ > + u32 clk_gate[2]; > + u32 div_reg[3]; > + u32 fixed_div; > + struct clk *clk; > + struct socfpga_clk *socfpga_clk; > + const char *clk_name = node->name; > + const char *parent_name[SOCFGPA_MAX_PARENTS]; > + struct clk_init_data init; > + int rc; > + int i = 0; > + > + socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL); > + if (WARN_ON(!socfpga_clk)) > + return; > + > + rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2); > + if (rc) > + clk_gate[0] = 0; > + > + if (clk_gate[0]) { > + socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0]; > + socfpga_clk->hw.bit_idx = clk_gate[1]; > + > + gateclk_ops.enable = clk_gate_ops.enable; > + gateclk_ops.disable = clk_gate_ops.disable; > + } > + > + rc = of_property_read_u32(node, "fixed-divider", &fixed_div); > + if (rc) > + socfpga_clk->fixed_div = 0; > + else > + socfpga_clk->fixed_div = fixed_div; > + > + rc = of_property_read_u32_array(node, "div-reg", div_reg, 3); > + if (!rc) { > + socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0]; > + socfpga_clk->shift = div_reg[1]; > + socfpga_clk->width = div_reg[2]; > + } else { > + socfpga_clk->div_reg = 0; > + } > + > + of_property_read_string(node, "clock-output-names", &clk_name); > + > + init.name = clk_name; > + init.ops = ops; > + init.flags = 0; > + while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] = > + of_clk_get_parent_name(node, i)) != NULL) > + i++; > + > + init.parent_names = parent_name; > + init.num_parents = i; > + socfpga_clk->hw.hw.init = &init; > + > + clk = clk_register(NULL, &socfpga_clk->hw.hw); > + if (WARN_ON(IS_ERR(clk))) { > + kfree(socfpga_clk); > + return; > + } > + rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); > + if (WARN_ON(rc)) > + return; > +} > + > static void __init socfpga_pll_init(struct device_node *node) > { > socfpga_clk_init(node, &clk_pll_ops); > @@ -160,6 +330,12 @@ static void __init socfpga_periph_init(struct device_node *node) > } > CLK_OF_DECLARE(socfpga_periph, "altr,socfpga-perip-clk", socfpga_periph_init); > > +static void __init socfpga_gate_init(struct device_node *node) > +{ > + socfpga_gate_clk_init(node, &gateclk_ops); > +} > +CLK_OF_DECLARE(socfpga_gate, "altr,socfpga-gate-clk", socfpga_gate_init); > + > void __init socfpga_init_clocks(void) > { > struct clk *clk; > -- > 1.7.9.5